How to Organize a Production Drill Audit: Step-by-Step

Most shops manage their drill inventory the way they manage their refrigerator: they know approximately what is in there, they add things when they run out, and they throw things away when they notice something is bad. This works until the refrigerator has fourteen half-used bottles of condiments and nobody knows if the leftover thing in the back is still good.

A drill audit replaces intuition with a documented snapshot of the actual condition of your drill inventory. It takes a few hours depending on shop size, produces a clear picture of what you have, what needs attention, and what needs to be retired, and — when done on a regular cycle — creates a baseline that makes cost-per-hole calculations and resharpening ROI visible.

Here is how to run one from start to finish.

Step 1: Pull All Drills From Rotation

The audit starts by physically collecting every drill in active use. This means checking every machine, every tool crib drawer, every toolbox, every "I'll get to these" pile on the bench, and any drills currently at a resharpening service waiting to return.

Do not audit machines individually. Pull everything to one location — a cleared bench works well — so you can see the full inventory at once. Drills scattered across twelve machines are impossible to assess; the same drills laid out on a 4-foot bench tell a different story.

What to collect: All HSS drills in rotation. Do not include drills in sealed new packaging — those are inventory stock, not in-use tools, and get counted separately. Do not include carbide drills in this pass unless you are specifically auditing them (carbide has different economics and failure modes).

Label machine sources as you pull. If a drill came out of the Bridgeport, mark it. If it came out of the CNC drill press, mark it. This helps later when correlating drill condition with specific machines — if all the bad drills came from one machine, that is a process or machine problem, not a tooling management problem.

Step 2: Sort by Size and Identify Duplicates

Before assessing condition, organize by size. Group all 1/4" drills together, all #29 drills together, and so on. A 115-piece combination index helps here as a physical reference — lay the index case open and use it as a sorting guide.

During sorting, several things become visible immediately:

• Size gaps: Sizes you use but have no current inventory for (they broke and were not replaced, or they walked off)
• Unintended duplicates: Eight copies of one size sitting in the drawer because nobody tracked what was resharpened and what was stocked
• Unrecognized inventory: Drills in the shop that nobody remembers ordering and cannot identify — possibly left over from a job, possibly wrong size purchased in error
• Mixed quality levels: Premium cobalt drills mixed in with standard M2, running the same jobs with no differentiation

Document the count by size. A simple spreadsheet with size, quantity, and a condition column is sufficient.

Step 3: Assess Each Drill's Condition

With drills organized by size, assess each one. You need three tools: a loupe or jeweler's magnifier (10×), a micrometer or caliper, and a strong light source.

What to look for:

Cutting edge condition: Under magnification, each cutting lip should have a clean, sharp edge with consistent relief behind it. Look for: rounded or chipped edge (worn), large flat wear land on the relief face (dull), microchipping along the edge (thermal damage or hard material contact), missing material at the corner (broken out).

Web thickness: The web is the central core of the drill that connects the two flutes. As the drill is shortened through resharpening, the web gets thicker at the new cutting end (the taper increases toward the shank). A drill with a thick web requires excessive thrust to push the chisel edge through the material, generating heat and reducing hole quality. You can estimate web thickness by looking at the point from the end — the chisel edge (the flat line across the tip) should be narrow relative to the drill diameter. A chisel edge wider than 15–20% of drill diameter indicates web growth that needs a web thinning operation.

Shank condition: Inspect the shank for chuck jaw marks (gouges from overtightening), corrosion, bending, and diameter at two or three points to check for wear. A shank worn significantly below nominal diameter will not hold concentrically in the chuck.

Remaining length: Measure overall drill length and compare to new length for that size (available from manufacturer charts or tool catalogs). Excessive shortening means fewer resharpening cycles remain before retirement. For a jobber-length 1/2" drill, new length is approximately 6". If an in-use drill measures 5" overall, it still has usable life. If it measures 4-1/4", it may have one or two resharpening cycles remaining.

Step 4: Sort Into Three Categories

After assessing each drill, assign it to one of three categories. Write the category on a piece of tape on the shank, or drop it into a physical bin.

KEEP (Ready to Use): Edge is sharp, geometry is good, web is not excessively thick, shank is clean, adequate remaining length. This drill goes back into rotation as-is.

SHARPEN: Edge is dull, chipped, or showing wear lands, but: the drill has enough remaining length to survive another sharpening, the web thickness is manageable (or web thinning should be requested), and the shank is acceptable. This drill goes into the resharpening batch — either to your in-house grinder or to a mail-in service.

Size matters here: below 1/4" diameter, sharpening economics are marginal. Below 3/16", replacement is almost always cheaper than resharpening. Know your size threshold and sort accordingly.

RETIRE: Shank damage, excessive shortening (under minimum usable length), broken or missing flute sections, severe thermal damage visible as surface discoloration with edge microcracking, or geometry so distorted that resharpening cannot economically restore it. Retire means disposal — do not keep it "just in case."

Step 5: Build the Decision Matrix Log

The audit is not useful if the results live only in your head. Log what you found.

A minimal audit log contains:

• Audit date
• For each size: quantity audited, quantity keep/sharpen/retire, notes on specific issues found
• Total cost of the sharpen batch (estimated or quoted)
• Identified gaps (sizes with zero usable inventory that need restocking)
• Machine correlations if any sizes show consistently worse condition on a specific machine

Store the log where future audits can reference it. After two or three audit cycles, patterns emerge: which sizes wear fastest in your material mix, which machines are hardest on tools, how long a sharpened drill typically lasts before needing another cycle.

Step 6: Execute the Sharpen Batch

The sharpen pile from the audit is the resharpening batch. If using an outsourced service, package by size group, include your web thinning instructions for drills flagged with thick webs, and ship with a return list. The audit log becomes your receiving inspection checklist — when the batch returns, verify count by size against what was sent.

Timing the audit to align with your resharpening cycle makes this efficient. If you use a mail-in service with a 5-business-day turnaround, plan the audit so the shop is not without critical sizes during the resharpening window. Keep a buffer of sharp spares in the sizes you cannot afford to run without.

Audit Frequency

For most production shops, a full audit every 3–4 months is the right cadence. Enough time passes between audits for meaningful data accumulation, but not so long that tooling problems compound undetected. High-volume shops or shops running hard materials may benefit from monthly audits of their highest-turnover sizes and quarterly full audits.

Between formal audits, many shops use a simple ongoing system: a "sharpening bin" that operators drop drills into when they pull them from service. The bin gets reviewed and processed weekly or biweekly. This is not a substitute for the full audit — it misses drills still in machines, inventory accumulation, and condition assessment — but it keeps the sharpen/retire cycle moving between formal reviews.