Most small shops handle drill bits the same way: run them until they squeak, then dig through the drawer for a replacement. It works until it doesn't — and when it doesn't, you're chasing a $40 broken tap out of a part that took three hours to get to.
A basic maintenance program changes that. It doesn't need to be complicated. Here's how to build one that actually gets used.
Downtime. A dull bit walking, oversizing a hole, or snapping mid-feature shuts down a machine. The cost isn't the bit — it's the 45 minutes diagnosing the problem, the scrapped part, the interrupted job.
Tooling costs. Most shops throw away bits that still have 3–5 resharpenings in them. A bit that costs $8 and gets discarded twice as often as it should costs $16. Multiply that across 200 bits and the math hurts.
Repeatability. Sharp, correctly-ground bits produce consistent hole sizes and finishes. Bits run past their useful life don't — and those inconsistencies end up as inspection failures downstream.
Start with what you actually have. Pull everything out of every drawer, every tool crib shelf, every machine cabinet. Sort by size. You're looking for bits with visible damage, bits that are clearly dull, bits with unknown condition, and bits that are sharp and serviceable.
Retire the damaged ones. Set aside the questionable ones for inspection. Keep the sharp ones in active rotation. This first pass usually reveals a drawer full of bits in unknown condition that nobody trusts but nobody throws away. That's where a lot of downtime comes from — operators grabbing a "probably fine" bit and running with it.
Most shops use a relatively small range of drill sizes for 80% of their work. Figure out which sizes you drill most often — those are your priority sizes for the program. For each priority size, decide the minimum count in rotation and the trigger point for reorder or resharpen.
A simple example: you drill a lot of 3/8" holes. You decide you want 6 sharp 3/8" bits in rotation at all times, and you'll resharpen or reorder when you're down to 2. That's the whole policy for that size. Write it down somewhere visible in the tool crib. A laminated index card works fine.
The goal is to use bits in sequence so you know which ones have the most wear and can pull them for resharpening before they fail in a part.
Simple physical system: Mark each bit with a paint marker dot or engraving at the shank. Bits go into rotation from the left side of a rack or bin. Operators always grab from the right side (oldest bits first). When a bit dulls, it goes into a "for sharpening" bin, not back into the main stock.
This FIFO approach ensures no single bit gets run to death while fresh ones sit untouched. It also means your sharpest bits are always on deck.
Reactive: Bits go to resharpening when operators notice performance degradation. Works fine in small shops where operators are engaged and experienced. Breaks down when operators just grab a fresh bit instead of flagging the dull one.
Proactive: Bits are pulled on a schedule — after X hours of use, after X number of holes in a given material, or on a calendar basis. More consistent, less dependent on individual operators.
Most small shops do best with a hybrid: reactive flagging of obviously dull bits plus a weekly 10-minute crib review where someone looks at the condition of everything in the "questionable" bin and makes a call.
In-house resharpening requires a drill grinding attachment or a dedicated drill grinder. Good ones start around $300–500. If you're doing volume and have someone who knows how to use it correctly, this makes sense. The risk is inconsistent geometry.
Mail-in resharpening makes sense for shops that don't want to invest in equipment or train someone. You batch up dull bits, ship them, and get them back sharp with consistent geometry. The turnaround is a few days, which is why you want a rotation — you're not waiting on bits you need tomorrow.
At MachinistPost, we handle HSS twist drill resharpening by mail. Cost runs $1–3 per bit depending on size. The key is batch shipping — if you're sending bits in one at a time, the economics get worse. Build up a batch of 10–20 before shipping.
A maintenance program that operators don't follow doesn't exist. Keep training short and practical: show them where to grab bits, show them the "for sharpening" bin and when to use it, explain why. Most machinists understand this intuitively — they just need a system to follow.
| Step | Action |
|---|---|
| 1 | Inventory and retire damaged bits |
| 2 | Standardize priority sizes, set min quantities |
| 3 | FIFO rotation — oldest bits used first |
| 4 | "For sharpening" bin, weekly review |
| 5 | Batch resharpen in-house or by mail |
| 6 | Train operators, reinforce consistently |
A well-run shop can maintain this in under an hour per week. The payoff is fewer surprises on the machine, lower tooling spend over time, and operators who aren't gambling on whether the bit they grabbed is any good.
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