Extend Your Drill Bits' Life: 7 Proven Maintenance Steps Every Machinist Swears By

A dull bit is a safety hazard, a waste of money, and a source of endless frustration. I learned that the hard way when a cheap HSS bit snapped in the middle of a kitchen remodel. Since then I’ve kept a tight routine on my bits, and the savings speak for themselves.

Why Bit Care Matters Now

Most of us run a shop or a garage where the drill is used daily. Bits get tossed into a toolbox, into a bag of junk, or left on a bench after a job. In that chaos they pick up metal shavings, oil, and rust. If you ignore the buildup, the cutting edges wear faster, the bit can overheat, and you end up replacing a $5 bit after a single use. A little upkeep extends life, cuts cost, and keeps the job safe.

Step 1: Clean Off Every Chip

After each job, wipe the shank and flutes with a clean rag. For stubborn chips, dip the bit in a bucket of warm soapy water, give it a gentle brush with a soft nylon brush, then dry it thoroughly. Never let water sit on the tip; moisture can cause rust in a matter of hours.

Pro tip: I keep a small spray bottle of light machine oil in my toolbox. A quick spray after cleaning adds a protective film that stops rust before it starts.

Step 2: Inspect the Cutting Edge

Look at the tip under a bright lamp. If you see nicks, burrs, or a rounded edge, the bit is losing its efficiency. Small burrs can be removed with a fine file or a piece of sandpaper wrapped around a dowel. Be careful not to over‑file – you want to keep the original geometry.

I once found a tiny nick on a cobalt bit that I thought was harmless. After a few more holes the bit started to wander, and the hole was out of round. A quick file saved the rest of the batch.

Step 3: Sharpen When Needed

Not every bit needs a professional sharpening service. For standard twist bits, a bench grinder set to a low speed works fine. Hold the bit steady, match the original angle (usually 118 degrees for HSS), and grind just enough to restore the edge. Too much grinding shortens the bit, so stop when the edge looks crisp.

If you’re uncomfortable with a grinder, a sharpening stone works too. I keep a 120‑grit stone for quick touch‑ups on the job site.

Step 4: Lubricate the Shank

The shank is the part that goes into the chuck. Over time it can develop a thin layer of rust or oil residue that makes the chuck slip. Lightly coat the shank with a drop of machine oil or a spray of WD‑40 before you store the bit. This keeps the chuck grip tight and prevents rust from forming.

Step 5: Store Properly

Never toss bits loose in a drawer. Use a magnetic bit holder, a zip‑lock bag, or a dedicated bit case. Separate bits by size and type so you don’t have to dig around and risk bending a tip. I label each compartment in my wall‑mounted rack – a small habit that saves minutes every day.

Step 6: Use the Right Speed and Feed

Every material has a recommended RPM (revolutions per minute) and feed rate. Running a high‑speed steel bit at too high a speed in steel creates heat, which dulls the edge fast. Conversely, a low speed in wood can cause the bit to chatter and wear the flutes.

A quick reference chart on my shop wall reminds me: steel – 500‑800 RPM, wood – 1500‑2500 RPM, plastic – 2000‑3000 RPM. Adjust the feed so the bit bites, not slides.

Step 7: Rotate and Replace Strategically

Even with perfect care, a bit will eventually wear out. Keep a log of how many holes you’ve drilled with each size. When you notice a drop in performance – slower drilling, more force needed, or a rougher hole – it’s time to retire the bit.

I label the shank with a tiny piece of masking tape and a number. After about 150 holes in metal, I swap it out. The habit of rotating bits also spreads wear evenly across my inventory.

A Quick Recap

• Clean after each use
• Inspect the tip for damage
• Sharpen only when needed
• Lubricate the shank before storage
• Store in a dedicated holder or case
• Match speed and feed to material
• Track usage and replace at the right time

Following these seven steps has let me keep a set of 1/4‑inch HSS bits alive for over three years, a timeline most shops would envy. The next time you reach for a drill, remember that a little care now saves you time, money, and a lot of headaches later.