Best Drill Press Bits For Metal

When it comes to drilling metal with a drill press, the right bit isn’t just a suggestion, it’s the difference between a clean hole and a ruined workpiece or worse, a broken bit and frustration. The absolute best drill press bits for metal are those crafted from Cobalt M35 or M42 High-Speed Steel HSS, followed closely by Titanium Nitride TiN coated HSS for enhanced durability and lubricity. These materials offer the necessary hardness and heat resistance to cut through various metals, from mild steel to stainless, without losing their edge prematurely. You’re looking for bits designed for precision, longevity, and efficiency, allowing you to punch perfect holes every time. Think of it like a chef choosing the right knife – the material, grind, and coating all play a critical role in the final output and how much effort you expend.

Here’s a comparison list of top drill press bits for metal, designed to help you zero in on your next go-to set:

• DEWALT Cobalt Drill Bit Set

  

  • Key Features: M35 Cobalt steel, optimized for tough metals like stainless steel, split point tip for no-walk starts, includes a durable carrying case.
  • Average Price: $40-$70 for a common 14-piece set
  • Pros: Excellent heat resistance, superior durability for hard metals, self-centering tip.
  • Cons: Can be more brittle than standard HSS if mishandled, higher price point.

• BOSCH Cobalt M42 Drill Bit Set

  • Key Features: M42 Cobalt alloy 8% cobalt for increased heat and abrasion resistance, thick core for added stability, 135-degree split point for quick penetration.
  • Average Price: $50-$90 for a common 14-piece set
  • Pros: Exceptional performance on difficult metals, very long lifespan under proper use, reduced walking on start-up.
  • Cons: Higher cost, requires careful handling to prevent breakage.

• Irwin Industrial Tools Cobalt M-35 Metal Index Drill Bit Set

  • Key Features: M-35 Cobalt HSS, 135-degree split point, heavy-duty web construction for increased strength, includes a sturdy metal index case.
  • Average Price: $35-$60 for a common 29-piece set
  • Pros: Good value for a comprehensive set, strong performance on a variety of metals, durable case for organization.
  • Cons: Not as high cobalt content as M42 bits, individual bits might not last as long as premium M42 options in extreme applications.

• Milwaukee Red Helix Cobalt Drill Bit Set

  • Key Features: Patented RED HELIX design for rapid chip removal, 135-degree split point, M35 Cobalt steel, optimized for durability and faster drilling.
  • Average Price: $45-$80 for a common 15-piece set
  • Pros: Unique flute design enhances drilling speed and reduces heat build-up, very durable, excellent for deep holes.
  • Cons: May be slightly pricier than some entry-level cobalt sets, some users find the red coating wears off over time though this doesn’t affect performance.

• Neiko Titanium Nitride Coated HSS Drill Bit Set

  • Key Features: HSS with Titanium Nitride TiN coating, 135-degree split point, black and gold finish, comes in a sturdy metal index.
  • Average Price: $25-$45 for a common 29-piece set
  • Pros: TiN coating reduces friction and increases surface hardness, good general-purpose metal drilling, more affordable than cobalt.
  • Cons: TiN coating can wear off with heavy use, not as heat resistant or durable as cobalt for very hard metals.

• Drill America Cobalt Drill Bit Set

  • Key Features: M35 Cobalt HSS, 135-degree split point, industrial grade, black oxide finish, made in the USA.
  • Average Price: $60-$100 for a common 29-piece set
  • Pros: High-quality industrial-grade bits, reliable performance, good for professional use, often comes in large sets.
  • Cons: Higher cost, plain black oxide finish doesn’t offer the same friction reduction as TiN.

• Makita Cobalt M35 Drill Bit Set

  • Key Features: M35 Cobalt steel, 135-degree split point, polished finish, designed for use with impact drivers and drills.
  • Average Price: $30-$50 for a common 14-piece set
  • Pros: Durable for a wide range of metals, good value, often designed with features for general-purpose use like hex shanks.
  • Cons: May not include the largest sizes found in some other sets, primary focus often on cordless drill use, though perfectly fine for drill presses.

Understanding Drill Bit Materials: Your First Line of Defense Against Metal

When you’re staring down a piece of steel, the material of your drill bit is paramount.

It’s like picking the right tool for a specific job—you wouldn’t try to loosen a stuck bolt with a pair of pliers, right? For drilling metal, especially with a drill press where precision and consistency are key, the bit’s composition dictates its performance, lifespan, and what kind of metal it can effectively cut.

High-Speed Steel HSS: The Workhorse of the Workshop

High-Speed Steel, or HSS, is the baseline for general-purpose drilling.

It’s a fantastic upgrade from standard carbon steel bits because it can withstand much higher temperatures without losing its hardness.

This is crucial when friction from drilling generates heat, which happens quickly when cutting metal.

HSS bits are a good choice for drilling softer metals like aluminum, copper, and even mild steel, but they’ll struggle and dull quickly on harder alloys.

• Composition: Primarily iron, carbon, and chromium, often with tungsten, molybdenum, or vanadium for increased hardness and wear resistance.
• Key Benefits:
  • Cost-effective: Generally the most affordable option for metal drilling.
  • Versatile: Suitable for a range of softer metals and light-duty work on mild steel.
  • Resharpenable: Can often be sharpened if they dull, extending their life.
• Limitations:
  • Heat Sensitivity: Can lose temper and dull rapidly when drilling harder metals or at high speeds without proper coolant.
  • Wear Rate: Faster wear on harder materials compared to more advanced alloys.

Cobalt M35/M42 Drill Bits: The Heavy Hitters

If HSS is your everyday sedan, Cobalt bits are your performance vehicle.

These bits are made from High-Speed Steel that has been alloyed with a percentage of cobalt, typically M35 5% cobalt or M42 8% cobalt. The addition of cobalt significantly increases the bit’s hot hardness—its ability to retain sharpness at elevated temperatures.

This makes them ideal for drilling tough materials where standard HSS bits would quickly fail, such as stainless steel, cast iron, titanium, and other high-tensile alloys.

• Composition: HSS base with 5% M35 to 8% M42 cobalt.
  • Superior Heat Resistance: Excellent for drilling hard, abrasive metals without losing temper.
  • Enhanced Durability: Longer lifespan, especially in demanding applications.
  • Reduced Wear: Maintains a sharp edge for extended periods.
  • Self-Centering: Often feature a 135-degree split point for precise starts without walking.
  • Brittleness: More brittle than standard HSS. susceptible to breakage if subjected to sideways pressure or flexing, making proper drill press setup critical.
  • Cost: Significantly more expensive than HSS or TiN-coated bits.
• Real-World Application: Imagine needing to drill a dozen holes through a stainless steel plate for a custom bracket. Trying this with HSS would be an exercise in futility, likely resulting in multiple dulled bits. Cobalt bits, especially M42, will cut through with consistent performance, minimizing downtime and bit replacement.

Titanium Nitride TiN Coated HSS Drill Bits: The Friction Fighters

TiN coating is a must for HSS bits, giving them a distinctive gold color. This isn’t just for aesthetics. Massage Gun Cryotex

It’s a super-hard ceramic coating that significantly reduces friction and increases surface hardness.

While a TiN coating doesn’t make an HSS bit perform like a cobalt bit against extreme heat, it certainly improves its overall performance and lifespan when drilling softer to medium-hard metals.

The reduced friction means less heat generated, which in turn helps the bit stay sharper longer.

• Composition: HSS substrate with a thin layer of Titanium Nitride TiN applied via a physical vapor deposition PVD process.
  • Reduced Friction: Less heat build-up, leading to longer bit life and cleaner holes.
  • Increased Surface Hardness: Makes the bit more resistant to abrasion and wear.
  • Improved Chip Flow: Smoother chip evacuation due to the slippery surface.
  • Cost-Effective Upgrade: Offers a significant performance boost over plain HSS without the higher cost of cobalt.
  • Coating Wear: The coating is very thin and can wear off over time, especially during heavy use, after which the bit performs like standard HSS.
  • Not for Extreme Heat: While it reduces friction, the HSS core still has limitations at very high temperatures.
  • Resharpening Impact: Sharpening the bit removes the TiN coating from the cutting edge, effectively turning it into a regular HSS bit at that point.

Essential Features of Drill Press Bits for Metal

Beyond the material, several design features play a critical role in how effectively a drill bit performs on metal when mounted in a drill press.

Think of these as the engineering tweaks that make a great bit truly exceptional.

Getting these details right means less frustration, cleaner holes, and a longer life for your bits.

Split Point vs. Standard Point

This is arguably one of the most important features for drilling metal, especially when starting a hole.

• 135-Degree Split Point Self-Centering: This design eliminates the need for a pilot hole or center punch in most applications. The split point has an additional cutting edge that prevents the bit from “walking” or wandering on the surface of the workpiece. It bites immediately and precisely, which is invaluable when you’re aiming for accuracy on a drill press.
  • Advantages:
    • No Walking: Starts holes exactly where you want them, reducing material damage.
    • Faster Penetration: The aggressive cutting action digs in quickly.
    • Reduced Drilling Pressure: Requires less downward force, making it easier on your drill press and extending bit life.
    • Ideal for Hard Metals: Especially beneficial for materials like stainless steel where precise starting is difficult.
• 118-Degree Standard Point: This is the common point angle you’ll see on general-purpose drill bits. Without a split point, these bits tend to wander on metal surfaces unless you use a center punch and/or a pilot hole.
  * Cost-Effective: Generally cheaper to manufacture.
  * Versatile: Works well for wood, plastics, and softer metals with proper setup.
  • Disadvantages for Metal:
    • Walking: Prone to wandering, requiring careful starting.
    • Needs Pilot Hole: Often requires a pilot hole for accurate placement, especially on harder metals.
    • Increased Pressure: Requires more downward force to initiate the cut.

Flute Design and Chip Evacuation

The flutes are the spiral grooves running up the drill bit.

Their design is crucial for evacuating chips the metal shavings from the hole as you drill. Westinghouse Wgen9500Df Reviews

Proper chip evacuation prevents clogging, reduces heat build-up, and ensures a cleaner cut.

• Standard Flutes: Common on general-purpose bits, effective for most materials, but can sometimes struggle with deep holes or gummy metals.
• Optimized Flute Designs e.g., Milwaukee Red Helix: Some manufacturers engineer specific flute geometries to improve chip removal and reduce heat. A wider, more aggressive helix angle can move chips out faster, which is critical for deep holes and preventing re-cutting chips.
  • Benefits of Good Flute Design:
    • Efficient Chip Removal: Prevents chips from packing in the hole, which can cause heat build-up and bind the bit.
    • Reduced Heat: Less friction from re-cutting chips means a cooler bit and workpiece.
    • Smoother Drilling: A consistent flow of chips leads to a more stable drilling process.
    • Longer Bit Life: Reduced heat and friction prolong the cutting edge.

Shank Type

The shank is the non-cutting end of the drill bit that fits into the drill press chuck.

• Round Shank: The most common type. Works universally with standard drill chucks. Ensure your chuck jaws are clean and tighten securely to prevent slippage.
• Tri-Flat 3-Flat Shank: Features three flattened sides on the shank.
  * Improved Grip: Prevents slippage in the chuck, especially beneficial when drilling larger holes or tough materials that exert high torque.
  * Reduces Chuck Wear: Less slipping means less wear on the chuck jaws.
• Hex Shank: Typically found on bits designed for impact drivers, but also work in drill press chucks.
  * Excellent Grip: Virtually eliminates slippage.
  * Quick Changes: Very fast to insert and remove from quick-change chucks.
  • Disadvantages:
    • Not as common on larger diameter metal-specific bits.

Surface Treatment/Finish

While not a material, the finish on a drill bit can affect its performance, especially in terms of friction and corrosion resistance.

• Bright Finish No Coating: Standard on many HSS bits. Offers no added lubricity or corrosion resistance.
• Black Oxide Finish: A common coating that reduces friction and provides some corrosion resistance, helping to prolong bit life. It’s often seen on HSS and some cobalt bits.
• Bronze/Gold Finish TiN Coating: As discussed, Titanium Nitride TiN provides a hard, low-friction surface.
• Polished Finish: A smooth, highly polished surface can also reduce friction, though it’s typically found on premium bits and less common than coatings.

Optimizing Drill Press Usage for Metal Drilling

A great drill bit is only part of the equation.

Maximizing its performance and longevity when drilling metal with a drill press requires proper technique, setup, and maintenance. This isn’t just about getting the job done.

It’s about doing it right, safely, and efficiently.

Correct Speed and Feed Rate

This is probably the single most critical factor for successful metal drilling.

Drilling too fast generates excessive heat, quickly dulling your bit.

Drilling too slow can lead to rubbing and inefficient chip removal. Best Massage Gun With Heat

• Speed RPM: Measured in Revolutions Per Minute, this depends on the diameter of the drill bit and the type of metal you’re drilling.
  • Smaller Bits, Softer Metals: Generally higher RPMs.
  • Larger Bits, Harder Metals e.g., Stainless Steel: Significantly lower RPMs.
  • General Rule of Thumb: As bit diameter increases, RPM decreases. As metal hardness increases, RPM decreases.
  • Example Speeds:
    • Aluminum: 1/4″ bit: 2000-3000 RPM. 1/2″ bit: 1000-1500 RPM
    • Mild Steel: 1/4″ bit: 700-1000 RPM. 1/2″ bit: 350-500 RPM
    • Stainless Steel: 1/4″ bit: 300-500 RPM. 1/2″ bit: 150-250 RPM
  • Listen to the Bit: A good sign you’re drilling at the right speed is a continuous, curling chip. If you’re getting dust or blue chips, you’re too fast. If you’re getting no chip and just rubbing, you might be too slow or not applying enough feed pressure.
• Feed Rate Pressure: This is the rate at which you plunge the bit into the material.
  • Consistent Pressure: Apply steady, firm pressure to ensure the bit is cutting, not just rubbing. Too little pressure causes rubbing and heat. Too much pressure can overload the bit and cause breakage.
  • Breakthrough: As the bit approaches breakthrough, ease up on the pressure to prevent grabbing, burring, and potential bit breakage.
  • Listen and Feel: You should hear a consistent cutting sound, not a screeching or groaning.

Proper Workpiece Clamping

Never, ever hand-hold metal while drilling, especially with a drill press.

This is a primary safety rule and a critical factor in achieving accurate holes.

• Secure Vises: Use a drill press vise to securely hold smaller workpieces. Ensure the vise itself is clamped or bolted to the drill press table.
• Clamps: For larger or irregular workpieces, use C-clamps or hold-down clamps to firmly secure the material to the drill press table.
• Support: Ensure the workpiece is fully supported, especially when drilling through. If the material flexes, it can bind the bit.
• Prevent Rotation: The primary goal is to prevent the workpiece from spinning with the bit, which is incredibly dangerous and can damage both the material and the bit.

Lubrication and Cooling

Heat is the enemy of drill bits when cutting metal.

Proper lubrication and cooling are indispensable for extending bit life, improving cut quality, and preventing work hardening of the metal.

• Cutting Fluid/Oil: This is not optional for metal drilling. A good quality cutting oil or fluid serves multiple purposes:
  • Lubrication: Reduces friction between the bit and the workpiece, lowering heat.
  • Cooling: Carries heat away from the cutting edge.
  • Chip Evacuation: Helps flush chips out of the hole.
  • Improved Finish: Leads to cleaner, smoother holes.
• Application: Apply cutting fluid generously and continuously, especially for deep holes. For through-holes, you can apply it from both sides if possible.
• Types of Fluid:
  • General Purpose Cutting Oil: Good for most metals.
  • Tapping Fluid: Excellent for hard metals like stainless steel.
  • Lubricating Oils e.g., 3-in-1 oil: Can work in a pinch for softer metals but are not as effective as dedicated cutting fluids.
• Signs of Insufficient Cooling:
  • Smoking: Your bit is getting too hot.
  • Blue Chips: The metal chips are turning blue, indicating excessive heat.
  • Rapid Dullness: Your bit loses its edge quickly.

Pilot Holes When Necessary

While 135-degree split point bits largely eliminate the need for a center punch, pilot holes are still invaluable for certain applications.

• Large Diameter Holes: For holes larger than, say, 1/2 inch 12-13mm, drilling a pilot hole with a smaller bit first e.g., 1/4″ or 6mm makes the job much easier and safer. It reduces the load on the larger bit, helps it start accurately, and ensures a cleaner cut.
• Hard Metals with Standard Point Bits: If you’re using a bit without a split point on hard metal, a pilot hole is essential to prevent wandering.
• Accuracy: For extremely precise hole placement, a small pilot hole drilled with a sharp, high-quality bit can ensure the final larger hole is exactly where you want it.

Drill Bit Maintenance and Sharpening

Even the best drill bits won’t last forever without proper care.

Think of it like taking care of your car—regular maintenance keeps it running optimally.

For drill bits, this means cleaning, proper storage, and knowing when and how to sharpen them.

Cleaning After Use

This seems basic, but it’s often overlooked.

Metal chips and cutting fluid residue can adhere to the bit, potentially leading to corrosion or affecting performance. Top Gaming Ultrawide Monitors

• Brush Off Chips: Use a stiff brush or an air compressor to remove all metal chips. Be careful not to damage the cutting edges.
• Wipe Down: Wipe the bit clean with a rag, especially if you’ve used cutting fluid. This removes residue and prevents gumming up.
• Degrease Optional: For bits that have been heavily used with sticky coolants, a quick wipe with a degreaser can be beneficial before storage.

Proper Storage

How you store your bits directly impacts their longevity and ease of use.

• Dedicated Cases/Indexes: The best way to store drill bits is in their original index or a dedicated drill bit case. This keeps them organized, prevents them from rattling against each other which can dull edges, and protects them from rust.
• Separation: If you don’t have a case, store bits separately to prevent their cutting edges from coming into contact with other bits or tools.
• Dry Environment: Store bits in a dry environment to prevent rust and corrosion. If you’re in a humid area, consider using desiccant packs in your storage containers.
• Light Oil Coat: For long-term storage, especially for carbon steel or HSS bits, a light coat of machine oil can provide an extra layer of rust protection.

Sharpening Drill Bits

Knowing how to sharpen a drill bit or when to send it out for sharpening can save you money and keep your drilling precise.

A dull bit not only performs poorly but can also generate excessive heat, work-harden your material, and potentially break.

• When to Sharpen:
  • Visible Wear: Look for rounded edges on the cutting lips, nicks, or chips.
  • Poor Performance: If the bit starts rubbing instead of cutting, producing fine dust instead of chips, or generating excessive heat.
  • Increased Pressure: If you need significantly more downward force to make the bit cut.
• Methods of Sharpening:
  • Manual Sharpening Grinder: This requires skill and practice to maintain the correct angles point angle, lip relief angle. A bench grinder with an aluminum oxide wheel is commonly used. It’s challenging to get it perfectly right, especially for split points.
  • Drill Bit Sharpeners: These are specialized jigs or machines e.g., Drill Doctor that hold the bit at the correct angles and guide it against a grinding wheel. They make sharpening much easier and more consistent for the average user.
    • Advantages: User-friendly, produces consistent results, often can recreate split points.
    • Disadvantages: Initial cost of the sharpener, some models may not accommodate all bit sizes or types.
  • Professional Sharpening Services: For expensive or very large bits, sending them to a professional sharpening service is often the best option. They have specialized equipment to restore bits to like-new condition.
• Cobalt and TiN Coated Bits:
  • Cobalt: Can be sharpened, but requires careful technique due to their brittleness. The high hot hardness means they typically hold an edge much longer, so sharpening is less frequent.
  • TiN Coated: Sharpening removes the TiN coating from the cutting edge. While the bit will still function as a standard HSS bit after sharpening, it loses the benefits of the coating. For this reason, some users opt not to sharpen heavily coated bits and instead replace them.

Safety First: Essential Precautions for Drill Press Use

Working with a drill press, especially when drilling metal, carries inherent risks.

Ignoring safety precautions isn’t just about avoiding minor injuries. it’s about preventing severe accidents.

Treat your drill press with respect, and it will serve you well.

Eye Protection Safety Glasses

This is non-negotiable.

Metal chips, especially when drilling, are often hot and can fly at high speeds.

• Always Wear Them: Whether you’re drilling, setting up, or just observing, safety glasses should be on.
• Side Shields: Opt for glasses with side shields for maximum protection.
• Prescription Glasses are Not Enough: If you wear prescription glasses, you still need to wear safety glasses over them, or use prescription safety glasses.

Hand Protection Gloves – With Caution

Gloves can be a double-edged sword around rotating machinery.

• General Rule: Avoid wearing gloves when operating a drill press with small or intricate workpieces, as the glove can get caught and pull your hand into the bit.
• When to Consider Gloves: For large, rough metal workpieces where there’s a risk of cuts from sharp edges or burrs while handling the material before and after drilling. Remove gloves before operating the drill press.
• Best Practice: Use a brush or specific tool to clear chips, never your bare hands.

Workpiece Securing

As discussed, this is paramount for safety and quality. Dewalt Nail Gun Not Working

• Never Hand-Hold: Reiterate this: never hand-hold any workpiece, especially metal. If the bit grabs, the workpiece will spin violently and can cause severe injury.
• Clamp/Vise: Always use a drill press vise or appropriate clamps to secure the workpiece to the drill press table.
• Bolt Down Vise: Ensure the vise itself is clamped or bolted to the drill press table. Even a heavy vise can shift under drilling pressure.

Proper Attire

Loose clothing, jewelry, and long hair are significant hazards around rotating machinery.

• No Loose Clothing: Roll up sleeves, tuck in shirts, and avoid dangling drawstrings or ties.
• Remove Jewelry: Rings, watches, necklaces, and bracelets can get caught and cause degloving injuries or pull you into the machine.
• Tie Back Long Hair: Long hair should be tied back or tucked under a cap to prevent it from getting entangled.

Emergency Stop Awareness

Know where the emergency stop button or power switch is on your drill press.

• Familiarize Yourself: Before you start drilling, identify and practice reaching the power switch or emergency stop.
• In Case of Jam: If the bit jams, the workpiece spins, or any other emergency occurs, hitting the power is your first response.

Good Ventilation

Drilling metal, especially with cutting fluids, can produce fumes.

• Ventilation: Ensure your workspace is well-ventilated to avoid inhaling fumes or metal dust.
• Dust Collection Optional: While more common for wood, some drill presses can be adapted for chip collection if you’re doing high-volume work.

When to Consider Specialty Bits for Metal

While cobalt and TiN-coated HSS bits cover 90% of your metal drilling needs, there are specific situations and materials where specialty bits truly shine.

These aren’t your everyday bits, but they’re invaluable when you encounter particular challenges.

Step Drills

Also known as unibits, step drills are cone-shaped bits with multiple diameters in steps.

• Purpose: Ideal for drilling thin sheet metal, plastics, and conduit boxes where you need to create multiple sized holes without changing bits, or deburring a hole.
• Advantages for Metal:
  • Deburring: Each step deburrs the previous hole as it drills.
  • Single Bit, Multiple Sizes: Eliminates the need to switch bits for different hole diameters.
  • Clean Holes: Produces very clean, round holes in thin materials.
  • Reduced Walking: Self-starting tips are common.
  • Thin Materials Only: Not suitable for thick materials typically max 1/8″ – 1/4″ thickness, depending on the bit.
  • Limited Depth: Can only drill holes up to the length of the step.
  • Not for Through-Holes in Thick Material: If you need a consistent diameter through a thick piece, a standard twist drill is better.
• Material: Usually HSS or TiN-coated HSS. Cobalt versions exist for tougher sheet metals.
• Application: Perfect for electrical enclosures, automotive bodywork, or creating custom panels.

Annular Cutters Hole Saws for Metal

Annular cutters, often used with magnetic drills but can be adapted for drill presses with the right arbor, cut a circular ring out of the material, leaving a slug in the center.

• Purpose: For drilling large diameter holes typically 1/2″ or larger in thick plate steel, structural steel, or pipes.
  • Faster Cutting: Because they only cut the circumference, they are significantly faster than twist drills for large holes.
  • Less Power Required: Lower horsepower machinery can handle larger diameters.
  • Cleaner Holes: Produces burr-free holes.
  • Longer Bit Life: Spreads the cutting load over multiple teeth.
  • Cost: Much more expensive than twist drills.
  • Requires Pilot Pin: Needs a pilot pin to eject the slug and guide the cutter.
  • Specific Arbors: Requires specialized arbors to fit drill press chucks, and not all drill presses are robust enough for very large cutters.
• Material: HSS, Cobalt, or Tungsten Carbide Tipped TCT. TCT versions are for the hardest materials.
• Application: Fabrication shops, structural steel work, bridge construction.

Countersink Bits

While not strictly for drilling a hole through metal, countersink bits are essential for preparing a hole for flat-head screws.

• Purpose: To create a conical recess around the top of a drilled hole, allowing the head of a flat-head screw or rivet to sit flush or below the surface.
  • Clean Finish: Provides a professional, flush finish.
  • Prevents Stress: Distributes pressure evenly around the screw head, reducing stress on the material.
  • Deburring: Can also be used to quickly deburr the edge of a drilled hole.
• Types: Single flute, three-flute, and multi-flute designs are common.
• Material: HSS or Cobalt.
• Application: Any project where you need to recess fasteners for a smooth surface, like automotive repairs, metal fabrication, or machinery assembly.

Common Problems and Troubleshooting When Drilling Metal

Even with the right bits and a solid drill press, you’ll inevitably run into challenges when drilling metal.

Knowing how to diagnose and fix these common problems can save you time, bits, and material. I Can Fall Asleep But Cant Stay Asleep

It’s like having a mechanic’s manual for your drilling operations.

Excessive Heat / Smoking Bit

This is arguably the most frequent issue and the primary cause of bit dulling and failure.

• Symptoms: Drill bit smokes, chips turn blue or purple, burning smell, bit loses its sharpness quickly.
• Causes:
  • Too High RPM: The most common culprit. The bit is spinning too fast for the material and diameter.
  • Insufficient Lubrication: Not enough cutting fluid to cool the bit and reduce friction.
  • Dull Bit: A dull bit generates excessive friction as it rubs instead of cuts.
  • Insufficient Feed Pressure: Not enough downward force means the bit is rubbing rather than aggressively cutting, leading to friction and heat.
• Solutions:
  • Reduce RPM: Consult a drill speed chart for the specific material and bit size. Always err on the side of slower.
  • Apply More Cutting Fluid: Generously and continuously apply cutting oil.
  • Sharpen or Replace Bit: If the bit is dull, it needs attention.
  • Increase Feed Pressure: Apply steady, firm downward pressure to ensure the bit is taking a proper chip.

Bit Walking / Wandering

When the drill bit doesn’t start exactly where you want it.

• Symptoms: The bit slides across the surface before biting, resulting in an off-center hole or marring the workpiece.
  • No Center Punch: The bit has no indentation to guide it.
  • Standard Point Bit: A 118-degree point bit without a split point is prone to walking.
  • Lack of Downward Pressure: Not enough force for the bit to engage the material.
  • Center Punch: Always use a center punch to create an indentation before drilling, especially with standard point bits.
  • Use Split Point Bits: Invest in 135-degree split point bits, which are inherently self-centering.
  • Start Slow: Begin drilling at a very low RPM until the bit has firmly engaged the material.
  • Pilot Hole: For larger holes, drill a small pilot hole first.

Breakage Bit or Workpiece

Bits can snap, or the workpiece can grab and spin violently.

• Symptoms: Bit snaps, workpiece spins rapidly, loud bang, potential injury.
  • No Workpiece Clamping: The workpiece is not secured and spins when the bit grabs. This is extremely dangerous.
  • Excessive Side Pressure: Applying sideways force instead of straight downward pressure.
  • Bit Overload: Too much feed pressure for the bit’s diameter or the material’s hardness.
  • Dull Bit: A dull bit can bind and grab.
  • Incorrect Point Angle: Improperly sharpened or manufactured bits can be weak.
  • Hitting the Table: Drilling too far through and hitting the drill press table.
  • ALWAYS Clamp Workpiece: This is paramount for safety.
  • Straight Downward Pressure: Maintain consistent, straight pressure.
  • Reduce Feed Pressure: Don’t force the bit. let it cut.
  • Use Sharp Bits: Dull bits are more likely to bind.
  • Proper Backing: Use a sacrificial piece of wood or plastic under your workpiece to protect the table and allow the bit to clear.

Burrs and Rough Holes

When the hole isn’t clean or has sharp edges.

• Symptoms: Raised, sharp edges around the drilled hole, uneven hole walls.
  • Dull Bit: A dull bit tears rather than cuts.
  • Improper Feed Rate: Too fast or too slow can lead to rough edges.
  • Incorrect RPM: Too fast can burnish the hole instead of cutting.
  • Lack of Lubrication: Increased friction and heat lead to poorer cut quality.
  • Incorrect Point Angle: A point that’s too shallow or too steep can contribute to poor finish.
  • Use a Sharp Bit: Ensure your bit is sharp and in good condition.
  • Optimize Speed and Feed: Adjust according to material and bit size.
  • Use Cutting Fluid: Ensure ample lubrication.
  • Deburr: Use a countersink bit, deburring tool, or file to clean up the edges after drilling.

Work Hardening Especially Stainless Steel

Certain metals, like stainless steel, can become harder if drilled incorrectly, making subsequent drilling even more difficult.

• Symptoms: The drill bit suddenly stops cutting, or seems to “skate” over the surface, even if it was previously cutting fine. The material surface appears burnished and shiny.
  • Insufficient Feed Pressure: Rubbing the bit on the surface without cutting it.
  • Too High RPM: Generating too much heat.
  • Dull Bit: A dull bit doesn’t cut effectively, leading to rubbing.
  • Aggressive Feed Rate: Apply consistent, firm pressure to ensure the bit is always cutting. Don’t let it rub.
  • Lower RPM: Use very slow speeds, especially for harder grades of stainless.
  • Use Cobalt Bits: Cobalt bits are far more resistant to the heat generated by work hardening.
  • Constant Lubrication: Essential for cooling and lubrication.
  • Don’t “Baby” It: Sometimes, you need to apply more pressure than you think to get the bit to bite and prevent work hardening.

Advanced Techniques and Considerations

Once you’ve mastered the basics, there are a few advanced techniques and considerations that can elevate your metal drilling game, especially when using a drill press for more intricate or challenging projects.

Peck Drilling for Deep Holes

When drilling holes deeper than about three times the bit’s diameter, continuous drilling can lead to several problems: chip packing, excessive heat build-up, and bit breakage. Peck drilling is the solution.

• Technique: Instead of plunging the bit all the way through, you drill in small increments, retracting the bit completely out of the hole after each “peck.”
• Benefits:
  • Chip Evacuation: Each retraction allows chips to clear from the flutes and the hole.
  • Cooling: Provides an opportunity to reapply cutting fluid directly to the cutting edge and allows air to cool the bit.
  • Reduced Heat: Prevents overheating and work hardening.
  • Prevents Bit Binding: Reduces the risk of the bit getting stuck or breaking due to packed chips.
• How to Peck:

  1. Start drilling with steady pressure.

  2. Drill down a short distance e.g., 1/4″ to 1/2″ depending on bit size and material. Perks Of Rowing Machine

  3. Retract the bit fully to clear chips and apply more cutting fluid.

  4. Repeat until the hole is complete.

• Advanced Peck Drilling: Some drill presses or digital readouts have peck drilling cycles that can automate this process, ensuring consistent depth for each peck.

Through-Hole vs. Blind Hole Considerations

The type of hole you’re drilling influences your technique and bit selection.

• Through-Holes: Holes that go all the way through the material.
  • Backing Material: Always use a sacrificial backing material wood, thick plastic under your workpiece. This prevents “breakout” jagged edges as the bit exits, protects your drill press table, and allows the bit to finish its cut without hitting metal.
  • Ease Pressure on Breakthrough: As the bit is about to break through, ease up on the feed pressure to prevent grabbing, violent workpiece spinning, and a rough exit hole.
• Blind Holes: Holes that do not go all the way through the material, stopping at a specific depth.
  • Depth Stop: Utilize your drill press’s depth stop feature. Set it carefully to the desired depth.
  • Chip Evacuation: Peck drilling is even more critical for blind holes to ensure chips are cleared. Packed chips can bind the bit and prevent it from reaching the full depth.
  • Bit Point Angle: For perfectly flat-bottomed blind holes, specialized “end mill” type drill bits or proper end mills on a milling machine are needed. Standard twist drills will always leave a conical point at the bottom due to their tip geometry.

Choosing the Right Cutting Fluid for Specific Metals

Not all cutting fluids are created equal.

Matching the fluid to the metal can yield superior results.

• Water-Soluble Coolants: These are often concentrated and mixed with water. They provide excellent cooling and are generally clean to work with. Good for general-purpose drilling of mild steel, aluminum, and cast iron.
• Straight Cutting Oils Sulfurized/Chlorinated: These are heavier, non-water-miscible oils. They provide superior lubrication and are excellent for tough metals like stainless steel, tool steel, and other exotic alloys where friction and heat generation are high. They often contain extreme pressure EP additives.
• Synthetics/Semi-Synthetics: Offer a balance of cooling and lubrication, often cleaner than straight oils. Good all-around choices.
• Tapping Fluid: A very aggressive cutting fluid, often used for tapping threads, but also highly effective for drilling very hard metals like stainless steel due to its excellent lubricity and extreme pressure properties.
• Aluminum: Use a specific cutting fluid designed for aluminum to prevent gumming and improve chip flow. Kerosene or mineral spirits can also be used, but dedicated aluminum cutting fluid is best.
• Cast Iron: Often drilled dry or with compressed air, as cast iron produces fine, dusty chips that can turn into a messy paste with liquid coolants. If using fluid, a flood coolant system is preferred to wash away chips.

Magnetic Drill Bases vs. Drill Presses

For very large or heavy metal workpieces, a traditional drill press might not be the most practical solution.

• Magnetic Drill Presses Mag Drills: These are portable drills with an electromagnetic base that clamps securely to ferrous metal surfaces.
  * Portability: Can be brought to the workpiece, ideal for large or fixed structures.
  * Capacity: Often designed to use annular cutters, allowing for very large holes in thick material.
  * Stability: The magnetic base provides rock-solid stability.
  * Limited to Ferrous Metals: Only works on steel, iron, etc.
  * Cost: More expensive than standard benchtop drill presses.
  * Specialty Use: Primarily for large, heavy-duty holes.
• When to Use a Mag Drill: When your workpiece is too large or heavy to easily maneuver onto a drill press table, or when you need to drill on site e.g., structural beams, heavy machinery.

Frequently Asked Questions

What are the best drill press bits for metal?

The best drill press bits for metal are typically Cobalt M35 or M42 High-Speed Steel HSS for their superior heat resistance and durability in hard metals, and Titanium Nitride TiN coated HSS for reduced friction and extended life in general metal drilling.

What’s the difference between M35 and M42 cobalt bits?

M42 cobalt bits contain a higher percentage of cobalt typically 8% compared to M35 5%, offering even greater hot hardness and abrasion resistance, making them superior for extremely hard metals like stainless steel and tool steel, though they can be more brittle.

Can I use regular HSS bits for drilling metal on a drill press?

Yes, you can use regular HSS bits for drilling softer metals like aluminum, copper, and mild steel.

However, they will dull quickly and struggle with harder metals like stainless steel, where cobalt or TiN-coated bits are much more effective. Gaming Pc Under 1

Do I need to use cutting fluid when drilling metal?

Yes, using cutting fluid or oil is highly recommended, if not essential, when drilling metal.

It lubricates the bit, reduces friction, dissipates heat, improves chip evacuation, and extends the life of your drill bit.

What speed should I use for drilling metal on a drill press?

The correct speed RPM depends on the drill bit’s diameter and the type of metal. Generally, slower speeds are required for larger bits and harder metals, while faster speeds can be used for smaller bits and softer metals. Always consult a drill speed chart.

Why is my drill bit smoking when drilling metal?

Your drill bit is likely smoking due to excessive heat. This is usually caused by too high RPM, insufficient cutting fluid, or a dull bit. Reduce speed, apply more lubricant, or sharpen/replace your bit.

How do I prevent the drill bit from walking on metal?

To prevent walking, use a 135-degree split point drill bit as it’s self-centering. Alternatively, for standard point bits, use a center punch to create an indentation before drilling, and start at a very low RPM.

Is a pilot hole necessary for drilling metal?

A pilot hole is not strictly necessary for all metal drilling, especially with self-centering 135-degree split point bits. However, it is highly recommended for larger diameter holes e.g., over 1/2″ to reduce the load on the larger bit and improve accuracy. It’s also essential for standard point bits on hard metals.

Can I sharpen cobalt drill bits?

Yes, cobalt drill bits can be sharpened, but they are more brittle than standard HSS, requiring careful technique.

Using a drill bit sharpener designed for proper angles is often the easiest and most effective method.

What is a split point drill bit?

A split point drill bit has an additional cutting edge at its tip, typically at 135 degrees, that allows it to start drilling precisely without “walking” or requiring a center punch, especially on hard, smooth surfaces like metal.

Why is my drill bit dulling so quickly?

Rapid dulling is usually due to excessive heat too high RPM, lack of coolant, insufficient feed pressure rubbing instead of cutting, or using the wrong type of bit for the hardness of the metal you’re drilling. Best Reviews Guide

What kind of cutting fluid is best for stainless steel?

For stainless steel, a heavy-duty cutting oil or tapping fluid with extreme pressure EP additives is best. Stainless steel work-hardens easily, so superior lubrication and cooling are critical.

How do I clamp metal securely on a drill press?

Always use a drill press vise or heavy-duty clamps to secure the metal workpiece to the drill press table. Never hand-hold metal when drilling, as it can spin dangerously.

What is the purpose of flutes on a drill bit?

The flutes spiral grooves on a drill bit serve to evacuate chips metal shavings from the drilled hole, prevent clogging, reduce heat build-up, and allow cutting fluid to reach the cutting edge.

Can I use a drill press for hardened steel?

Drilling hardened steel is very challenging. You would need carbide-tipped drill bits specifically designed for hardened materials, very slow speeds, and consistent, robust pressure with ample cutting fluid. Cobalt bits may work on some lower levels of hardened steel, but carbide is typically required for true hardened steel.

What’s the best way to clean drill bits after use?

After use, brush off all chips and wipe down the drill bit with a rag to remove residue and cutting fluid.

For long-term storage or in humid environments, apply a light coat of machine oil.

How do I store drill bits to prolong their life?

Store drill bits in their original index or a dedicated drill bit case to keep them organized, prevent contact with other bits which can dull edges, and protect them from rust and moisture.

What safety precautions should I take when drilling metal?

Always wear safety glasses, secure the workpiece firmly with a clamp or vise never hand-hold, tie back long hair, remove loose clothing and jewelry, and be aware of the emergency stop button.

What’s a step drill bit used for in metal?

A step drill bit is used for drilling multiple sized holes in thin sheet metal or plastic, as well as for deburring holes. It has multiple steps that cut progressively larger diameters.

Can I use a regular drill bit as a countersink?

No, a regular twist drill bit cannot be used as a countersink. Corded Massage Gun

A countersink bit has a specific conical shape designed to create a tapered recess for the head of a flat-head screw to sit flush.

Why does my drill bit grab the workpiece when breaking through?

This usually happens when you maintain too much feed pressure as the bit is about to break through the material. Ease up on the pressure just before breakthrough to prevent grabbing and ensure a clean exit.

What is work hardening in metal drilling?

Work hardening is a phenomenon where certain metals like stainless steel become harder as they are deformed or heated by rubbing.

If your drill bit is dull or you apply too little pressure, it can rub the metal, causing it to harden and making it even more difficult to drill.

How often should I re-apply cutting fluid?

For optimal performance and bit life, apply cutting fluid continuously or very frequently, especially when drilling deep holes or hard metals. Don’t let the bit or workpiece go dry.

Can I use a drill press to drill through thick steel plates?

Yes, a drill press is ideal for drilling through thick steel plates.

Use appropriate cobalt or carbide-tipped bits, very slow speeds, ample cutting fluid, and peck drilling for deep holes.

What’s the difference between drilling and milling with a drill press?

A drill press is designed for drilling creating round holes. While some light milling can be done with specialized attachments, it’s generally not recommended for milling creating slots or shaping as drill presses lack the rigidity and spindle bearings necessary for side loads, which can damage the machine.

Are titanium drill bits good for metal?

Titanium Nitride TiN coated HSS bits are good for general-purpose metal drilling, offering reduced friction and increased surface hardness compared to plain HSS.

However, they are not as heat resistant or durable for very hard metals as cobalt bits. Treadmill Belt Catching

What’s the ideal point angle for metal drilling?

A 135-degree split point is generally considered ideal for drilling metal, as it provides self-centering capabilities and better penetration on hard materials. A 118-degree standard point is common but less effective on metal without a pilot hole.

Can I drill cast iron dry?

Yes, cast iron is often drilled dry or with compressed air, as its fine, powdery chips can turn into a messy, abrasive paste when mixed with liquid coolants.

If using liquid, a flood coolant system is best to wash away chips.

Why is my drill bit squealing?

A squealing sound typically indicates that the drill bit is dull, not cutting effectively, or you’re using an incorrect speed/feed rate. It means the bit is rubbing rather than cleanly cutting the metal, generating excessive friction.

What is the “Red Helix” design in Milwaukee drill bits?

The “Red Helix” design in Milwaukee drill bits refers to a patented flute geometry that is engineered for rapid chip removal and reduced heat build-up, leading to faster drilling and longer bit life, especially in demanding applications.