How to Sharpen a Drill Bit: Step-by-Step Guide for Beginners and Pros

A dull drill bit can turn a simple job into a slow, noisy mess. The hard part is not knowing what angle to hold, how much metal to remove, or when a bit is too far gone. I use a simple shop method that works for most twist bits, and I will walk you through it step by step.

Quick Answer: How Do You Sharpen a Drill Bit?

To sharpen a drill bit, I inspect the tip, match the original point angle, grind each cutting lip evenly, keep a small relief angle behind the cutting edge, cool the bit often in water, and test it on scrap. A bench grinder is the most common method. A drill bit sharpener or jig gives more repeatable results, especially for beginners.

Can All Drill Bits Be Sharpened?

Drill bits that can usually be sharpened

Most standard shop bits can be sharpened more than once if the damage is light.

• HSS drill bits are the easiest to sharpen.
• Cobalt bits can be sharpened, but they run hotter and need a lighter touch.
• Black oxide bits sharpen much like regular HSS bits.
• Larger twist bits are usually the best bits to learn on because the tip geometry is easier to see.

Drill bits that are harder or less practical to sharpen

Some bits are possible to sharpen, but they are not always worth the time.

• Titanium-coated bits can be sharpened, but the coating at the tip is removed.
• Masonry bits often use carbide tips and need a different approach.
• Brad point bits need extra care to preserve the center point and spurs.
• Step bits and very small bits are harder to restore by hand.

When to sharpen vs. replace

I sharpen when the bit is just dull. I replace when the bit is cracked, badly chipped, burned blue from heat, or worn so short that it no longer drills straight. If the tip geometry is badly damaged, replacement is often faster and cheaper than trying to save it.

Signs Your Drill Bit Needs Sharpening

A dull bit gives warning signs before it completely quits. Watch for these problems:

• The bit takes longer to cut.
• You need more pressure to make progress.
• The bit squeals, smokes, or gets hot fast.
• The tip wanders before it bites.
• The hole comes out rough, oversized, or out of round.
• Instead of clean chips, the bit makes fine dust or tiny flakes.

Quick dull vs. damaged bit comparison table

Tools You Need to Sharpen a Drill Bit

Basic tools

I keep the setup simple for most shop work.

• Bench grinder
• Safety glasses
• Light work gloves if you prefer them
• Cup of water for cooling
• Marker to track what you grind off

Optional tools for better accuracy

These tools make the job easier, especially when you want repeatable results.

• Drill bit sharpening jig
• Drill Doctor or a similar drill bit sharpener
• Angle gauge
• Magnifying glass
• Diamond wheel for specialty bits and carbide work

Best grinding wheel types

For most HSS and cobalt bits, I like an aluminum oxide wheel. A clean, properly dressed wheel cuts cooler and gives better control. For carbide-tipped bits, a standard wheel is not ideal. That is where specialty wheels and more experience matter.

Drill Bit Anatomy Explained

Main parts of a drill bit

If you know the names of the parts, sharpening gets much easier.

• Point: the cutting tip of the bit
• Cutting lips: the two main cutting edges
• Chisel edge: the short line in the center of the tip
• Flutes: the grooves that carry chips out
• Margin: the narrow outer edge that guides the hole
• Shank: the part clamped in the drill or chuck
• Heel: the area behind the cutting edge

Why geometry matters when sharpening

A drill bit does not cut well just because it is pointy. The shape has to be right. I always check for four things: equal lip length, equal lip angle, proper relief angle, and a centered chisel edge. If one lip is longer than the other, the bit will cut a larger hole and walk off center.

Standard point angles in the USA

In machine shops, these angles follow the same basic geometry you will see in classic references like Machinery’s Handbook. For most home and shop work in the USA, two angles matter most: 118 degrees and 135 degrees.

Drill Bit Sizes Explained

Fractional, number, letter, and metric sizes

Drill bits in the USA are sold in four common systems:

• Fractional sizes: 1/16 inch, 1/8 inch, 1/4 inch, and so on
• Number sizes: #80 through #1
• Letter sizes: A through Z
• Metric sizes: 1 mm, 2 mm, 10 mm, and more

If you switch between inch and metric bits, the NIST SI unit guide is a solid reference for clear unit use and conversion basics.

Why size matters when sharpening

Size changes how easy the job feels. Small bits overheat fast and are easy to ruin. Large bits are easier to hold and inspect, so they are better for practice. Every sharpening pass removes metal, so repeated sharpening slowly shortens the bit. If both lips are not even, the bit can drill an oversize hole.

Most common drill bit sizes in the USA

Tap Drill Chart: Common Sizes Used in the USA

After sharpening, hole size matters even more when the hole will be tapped. A good sharp bit helps you hold size, start straighter, and cut cleaner threads. If you like to cross-check numbers, the Engineering Toolbox tap drill reference is handy.

Common tap drill size chart

Why sharpened drill bits matter for tapping

A dull bit can wander, rub, and cut an ugly hole. That makes tapping harder and increases the chance of a broken tap. A sharp bit starts cleaner, needs less force, and helps the tap follow a straighter path.

Step-by-Step: How to Sharpen a Drill Bit by Hand on a Bench Grinder

Step 1: Inspect the bit

Look for cracks, chips, heavy blue heat marks, and bent tips. If the bit is badly damaged, do not waste time trying to save it. I also check the original point angle before I grind anything.

Step 2: Mark the cutting edges

Use a marker on both lips. This simple trick shows where the wheel touches first. It helps beginners keep both sides even and avoids grinding more than needed.

Step 3: Set your grinder and stance

Adjust the tool rest so it supports your hands without getting too close to the wheel. Stand square to the grinder. Hold the bit firmly with both hands. I like to brace my elbows so the movement stays small and controlled.

Step 4: Grind the first cutting lip

Match the original point angle and touch the wheel lightly. Use a short, smooth motion. The goal is not to jam the tip into the wheel. You only want to remove a little metal from the lip and heel area.

Step 5: Create the relief angle

As the lip touches the wheel, gently lift and roll the shank downward so the heel ends up lower than the cutting edge. This relief is what lets the edge cut instead of rub.

Step 6: Grind the second lip to match

Turn the bit 180 degrees and repeat the same motion on the other lip. Try to make the lip length and angle match the first side. If one side gets longer, the chisel edge moves off center and the bit will drill poorly.

Step 7: Cool the bit frequently

Dip the bit in water after each short pass. If the tip turns blue, the steel may have lost hardness. Light passes and frequent cooling are better than one hot, aggressive grind.

Step 8: Check symmetry

Hold the bit straight toward your eyes and compare both lips. They should look equal in length and angle. The chisel edge should sit close to the center. If one side is off, touch up the longer lip.

Step 9: Test drill performance

Drill into scrap metal or wood. A properly sharpened bit should start with less pressure, cut without squealing, and produce clean chips. If it walks or cuts a rough hole, the tip still needs work.

Step 10: Fine-tune if needed

Small corrections make a big difference. If the bit wanders, one lip is usually longer or the point angle is wrong. If the bit rubs and heats up, the relief angle may be too flat.

How to Sharpen a Drill Bit with a Drill Bit Sharpener

When a sharpener is easier than a bench grinder

A drill bit sharpener is a great choice for beginners, small bits, and anyone who wants repeatable results. It also helps if you sharpen a lot of bits and do not want to freehand every one.

Basic process using a sharpening machine

Most sharpeners follow the same basic routine:

• Pick the correct collet or size setting.
• Insert the bit so it aligns with the guide.
• Set the angle for the bit style.
• Rotate or grind the bit as the machine directs.
• Inspect the tip, then test it on scrap.

Bench grinder vs. drill bit sharpener

How to Sharpen Different Types of Drill Bits

HSS drill bits

These are the easiest bits to learn on. They sharpen well on a bench grinder and respond quickly to light touch-up passes.

Cobalt drill bits

Cobalt bits are harder and more heat resistant, but they can still overheat at the edge while grinding. I use lighter pressure and cool them more often.

Titanium-coated bits

You can sharpen them, but the titanium coating at the tip gets ground away. The bit can still work well, but it no longer has that coating where it matters most.

Masonry bits

Masonry bits usually have a carbide insert at the tip. They are not sharpened the same way as twist bits, and many DIY users are better off replacing them unless they have the right wheel and experience.

Small drill bits

Small bits are easy to overheat and hard to hold at a steady angle. I recommend a jig or drill bit sharpener for these.

Large drill bits

Large bits are easier to inspect and freehand. They also make great practice bits because the cutting geometry is easier to see from the front.

Common Drill Bit Sharpening Mistakes

Uneven cutting lips

This is the most common mistake I see. It leads to wobble, oversized holes, and poor chip flow.

Wrong point angle

If the angle is too blunt or too sharp for the job, the bit will cut poorly and may wander in hard material.

Too much pressure on the grinder

Heavy pressure overheats the tip and removes too much metal too fast. Let the wheel do the work.

No relief angle

If the heel is not lower than the cutting edge, the bit rubs instead of cutting. That creates heat and frustration.

Overheating the bit

Blue color at the tip often means the steel got too hot and softened. Once the temper is gone, the edge will not stay sharp for long.

Ignoring the chisel edge

The chisel edge does not do much cutting, but it affects centering and feed pressure. If it is off center, the bit will not behave.

Pro Tips for Sharpening Drill Bits Like a Machinist

Use a marker to keep both lips even

I still do this on rough bits. It saves time and makes errors obvious.

Count grinding passes per side

If I take two light passes on one lip, I try to take two on the other. That simple habit helps keep the tip centered.

Check the point head-on after every pass

Do not wait until the end to inspect. A quick look from the front catches uneven lips before they become a bigger problem.

Practice on larger cheap bits first

Start with worn-out 3/8-inch or 1/2-inch HSS bits. They are easier to hold and easier to read.

Match the angle to the material being drilled

For general drilling, 118 degrees is fine. For tougher metals, 135 degrees often tracks better and needs less force.

Thin the web on heavily worn large bits

As a bit gets sharpened shorter, the web at the center gets thicker. On large bits, thinning the web can lower feed pressure and improve cutting. This is more advanced, so take it slow.

Use cutting fluid after sharpening for better performance

A sharp bit works even better when you control heat during drilling. I use cutting fluid on steel, stainless, and tough metals to help the edge last longer and to improve hole quality.

How to Test Whether a Drill Bit Is Sharp Enough

Visual inspection checklist

Before I drill, I look for:

• Sharp, clean cutting edges
• A centered tip
• Equal lip length
• Proper relief behind each edge

Drilling test checklist

On scrap material, a sharp bit should:

• Start quickly
• Cut without squealing
• Make clean chips
• Drill a round, clean hole
• Need less pushing force

What good chips look like in wood vs. metal

In metal, I want to see small curled chips, not dust. In wood, I want clean shavings and a clean hole edge. Dust, smoke, and heavy pressure usually mean the bit is still dull or the speed is too high.

Safety Tips When Sharpening Drill Bits

Wear eye protection

Grinding throws grit and sparks. Safety glasses are not optional. For basic PPE guidance, OSHA has a helpful page on eye and face protection.

Keep fingers clear of the wheel

Use a stable grip and never crowd the wheel. A small bit can grab if you get careless.

Do not overheat the bit

Short passes and frequent cooling help protect the temper of the steel.

Dress the grinding wheel if needed

A glazed or uneven wheel cuts poorly. A fresh wheel face gives better control and less heat.

Never sharpen cracked bits

A cracked bit can fail in the drill and become dangerous fast. Replace it.

Use proper lighting and stable footing

If you cannot clearly see the lips and chisel edge, you cannot sharpen accurately.

When You Should Replace a Drill Bit Instead of Sharpening It

Sometimes the smart move is replacement. I replace a bit when it has a cracked shank, broken tip, severe heat damage, or so much wear that it has become too short to cut well. I also replace cheap specialty bits when the time needed to restore them is greater than their value.

FAQ: How to Sharpen a Drill Bit

What is the correct angle to sharpen a drill bit?

Most general-purpose twist bits use a 118-degree point angle. Bits made for harder metals often use 135 degrees.

Can you sharpen a drill bit without a grinder?

Yes. A drill bit sharpener or sharpening jig can do it. Freehand sharpening without a grinder is possible, but it is harder to do accurately.

How do I know if both cutting edges are even?

Look at the bit head-on. The lips should match in length and angle, and the chisel edge should sit near the center.

Can titanium drill bits be sharpened?

Yes, but sharpening removes the titanium coating at the tip. The bit can still work, but it loses that coated edge.

Is it worth sharpening cheap drill bits?

Sometimes. It is usually worth it for larger bits or decent-quality steel bits. Very cheap or tiny bits are often faster to replace.

Why does my sharpened drill bit still wander?

The most common causes are uneven lips, an off-center chisel edge, or the wrong point angle for the material.

How often should drill bits be sharpened?

Sharpen them when cutting slows, heat goes up, or hole quality starts to drop. Do not wait until the bit is badly damaged.

Final Thoughts: Sharpening Drill Bits Saves Money and Improves Hole Quality

A sharp drill bit cuts faster, runs cooler, and makes cleaner holes. If you are new to this, start with a larger HSS bit and focus on one thing: make both lips match. Once you can do that, the rest gets much easier. Keep practicing, test on scrap, and your bits will stay useful a lot longer.