How to Sharpen Drill Bits at Home Like a Pro

By Drill Hog® | Published: 2026-10-17

Category: How-to Guides

Learn how to sharpen drill bits at home with a bench grinder or dedicated sharpener. Step-by-step guide to restore twist drills and extend their life.

Quick answer

You can sharpen drill bits at home using a bench grinder or a dedicated home drill bit sharpener. The key is maintaining the original point angle and relief angle. For standard twist drills, a 118° point angle works for most metals, while 135° is better for harder materials.

What You Need to Sharpen Drill Bits at Home

To sharpen drill bits effectively, you need a bench grinder with a fine-grit wheel (around 80-120 grit) or a dedicated home drill bit sharpener. A drill bit gauge helps you check the point angle and lip length after sharpening. The Drill Hog 29 Size Drill Gauge Size Checker (product ID 1290143) is a handy tool for verifying sizes from 1/16" to 3/4" after you sharpen. Safety glasses and a light touch are essential to avoid overheating the bit and ruining its temper.

When to Sharpen vs. Replace a Drill Bit

A dull drill bit produces smoke, requires excessive pressure, and leaves rough holes. If the cutting edges are chipped or the tip is rounded, sharpening can restore it. However, if the bit is severely worn, bent, or has broken flutes, replacement is more cost-effective. Left-hand drill bits, such as those in the Drill Hog 44 Pc Left Hand Drill Bit Set (product ID 1290139), are often used for extracting broken bolts and should be sharpened carefully to maintain their reverse-cutting geometry.

Common Mistakes to Avoid

Overheating the bit is the most common mistake during drill bit sharpening. Dip the bit in water frequently to keep it cool. Another error is removing too much material, which shortens the bit's life. Always match the original point angle and relief angle. Using a drill bit gauge to check your work after each pass helps maintain accuracy.

Step-by-Step Guide to Sharpen Drill Bits at Home

Step 1: Inspect the drill bit: Examine the cutting edges and tip. If the bit is chipped or heavily worn, consider replacement. For light dullness, proceed. Check the point angle (118° is standard for most metals). Skip sharpening if the bit is bent or flutes are cracked.
Step 2: Secure the grinder and set the tool rest: Mount a fine-grit wheel on your bench grinder. Set the tool rest to match the bit's original point angle (usually 59° from the wheel face for a 118° point). Keep a container of water nearby for cooling. A common mistake is setting the angle too steep, which weakens the cutting edge.
Step 3: Grind the first cutting edge: Hold the drill bit at the correct angle and lightly touch the cutting edge to the wheel. Use a sweeping motion to grind the relief angle behind the cutting lip. Apply light pressure and dip the bit in water every 2-3 seconds to prevent overheating. Overheating ruins the bit's hardness. Cool frequently.
Step 4: Grind the second cutting edge: Rotate the bit 180° and repeat the same grinding motion. Aim to remove an equal amount of material so both lips are the same length and angle. Uneven lips cause the bit to drill oversized or wobbling holes.
Step 5: Check with a drill bit gauge: Use the Drill Hog 29 Size Drill Gauge to verify the bit size and that both cutting lips are symmetrical. If needed, make a few more light passes to even them out. A gauge is the fastest way to confirm accuracy without guesswork.
Step 6: Test the sharpened bit: Drill a test hole in scrap metal. The bit should cut smoothly with minimal pressure and produce clean, consistent chips. If it still struggles, repeat the sharpening process. If the bit still smokes or binds after a second attempt, it may be time to replace it.

Products That Help with Drill Bit Sharpening

Drill Bit Gauge Measure Drill Bits Drill Gauge Hole Size Checker Tool Drill Hog: Drill Hog 29 Size Drill Gauge Size Checker for drill bits from 1/16" to 3/4" with 32 holes in fractional sizes. After sharpening, use this gauge to quickly verify the bit size and check that both cutting lips are equal length, which is critical for clean, straight holes.
44 Pc Left Hand Drill Bit Set Left Hand Drills Reverse Twist Moly M7 Drill Hog®: Drill Hog 44 Pc Left Hand Drill Bit Set includes 29 right hand fractional sizes from 1/16" to 1/2" in HI-Molybdenum M7 steel. If you use left-hand bits for bolt extraction, sharpening them correctly preserves their reverse-twist geometry. This set also gives you a wide range of common sizes for general drilling.