Inventory Management for Cutting Tools

Cutting tool inventory has two failure modes, and most shops live in one of them. The first is stockouts — you need a 25/64" drill to tap a hole and you don't have one, so the job sits while someone drives to the supplier or waits for a next-day order. The second is overstock — you have 40 drills in sizes you rarely use, money tied up in a metal tray, while your high-volume sizes are constantly out.

Good inventory management avoids both. Here's how to build a system that keeps your shop stocked correctly without carrying more than you need.

The Two Categories of Cutting Tool Inventory

Treat your tooling as two separate populations, because they're managed differently:

The distinction matters because these populations need different policies. Standard stock gets a par level and a reorder trigger. Job-specific tooling gets purchased for the job and reviewed afterward — if you ordered the same specialty bit three times in six months, it should move to standard stock.

Setting Par Levels

A par level is the minimum quantity of a given item you want on hand at all times. When you dip below par, you reorder. The calculation is straightforward:

Par = (daily usage rate) × (lead time in days) + safety stock

For drill bits, "daily usage rate" is how many of a given size you consume or pull for service per day on average. Lead time is how long it takes to get a replacement from your supplier. Safety stock is a buffer for demand variability and supplier delays.

Example: A 1/4" HSS jobber drill gets used heavily — you pull one for service every three days on average, and your supplier delivers in two days. Safety stock of two bits covers variability. Par = (0.33 per day × 2 days) + 2 = 3 bits. Round up to 4. When you're down to 4 bits in that size, reorder.

For sizes you use less frequently — once a month — a par of 2 (one in service, one as backup) is often sufficient.

Reorder Points vs. Periodic Review

Two systems work for managing when to reorder:

Continuous review (reorder point system): Every time a bit is issued from the crib, update the count. When the count hits the reorder point, trigger an order. This is precise but requires consistent logging of every issue and return. It works well if you have a dedicated crib attendant or a digital system.

Periodic review: On a set schedule (weekly is common for most shops), do a quick count of in-stock tools. Anything below par goes on the order. Less precise — you might go slightly below par between reviews — but much easier to maintain, especially in small shops without dedicated crib management.

Either system works. The most important thing is consistency. A system you actually use beats a perfect system that requires too much overhead to maintain.

Managing the Regrind Queue as Inventory

Bits in the regrind queue are not available inventory — they're like work-in-process. When you pull a drill for service, your available count drops. Don't wait until available count hits zero before sending bits out. Send batches before you're depleted.

The practical rule: when your available count hits par level, it's time to send the queue to service. You should never be in a situation where you've depleted available stock, the regrind batch is in transit, and you need that size now. Buffer your service cycle by initiating it before you're down to your last serviceable bit.

Storage and Crib Organization

Inventory management depends on accurate counts, and accurate counts depend on knowing where everything is. Basic storage requirements:

Single location per SKU: Each drill size should have one designated home in the crib. No overflow locations, no "just put it wherever there's room." If you can't find it, you can't count it.

Visual quantity indicators: For high-turnover sizes, a visual trigger is faster than counting. A line on the storage tray that indicates par level — when you can see the bottom of the tray, it's time to reorder — requires no logging or spreadsheet.

FIFO rotation: New stock goes behind or under existing stock. Oldest bits get used first. This matters most for bits in storage for longer periods where surface oxidation can be an issue.

Managing the Regrind Cost in Your Inventory Budget

Regrind costs belong in your tooling budget alongside purchase costs. If you're spending $200/month on new drill bits and $80/month on regrinding, your tooling budget is $280/month — not $200. Tracking both gives you the true cost of your drilling program and lets you make accurate comparisons when evaluating alternative tooling or service arrangements.

Shops that don't track regrind costs as part of the tooling budget often underestimate how much they're spending on cutting tools, and make decisions based on incomplete data. Add regrind to the line item.

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Inventory management for cutting tools is not a complex problem. Par levels, reorder triggers, a consistent process for issuing and receiving, and accurate counts are enough. The shops that get this right don't run out of tooling, don't carry dead stock, and can answer "what's this costing us?" with a number rather than a shrug.