Long-Run Economics: Resharpening vs. New Drills Over 5 Years

Arguments about resharpening versus buying new tend to be abstract. "It saves money" is intuitive but not compelling without numbers. This post puts actual figures behind the comparison — not to sell a service, but to give shops a framework they can apply to their own tooling consumption and make the decision with real data.

The Baseline Assumptions

For this comparison, we're working with a common production scenario: a shop that uses 3/8" HSS M2 jobber-length drill bits regularly, drills primarily mild steel (A36/1018), and runs a consistent volume. Adjust the numbers for your actual consumption, sizes, and materials.

Starting assumptions:

• Bit size: 3/8" HSS M2 jobber
• New bit cost (quality brand): $6.50 each
• Holes per new bit before dulling: 200 holes in mild steel
• Resharpen cost (mail-in service): $2.00 per bit
• Holes per resharpened bit: 185 holes (92% of new bit life)
• Resharpens per bit before retirement: 5 (typical for a quality bit)
• Shipping cost (batch of 10 bits): $8 round trip = $0.80/bit
• Monthly drilling volume: 1,000 holes in this size

Year 1: Establishing the Baseline

At 1,000 holes/month, the shop needs approximately 5 bits per month at 200 holes each (new) or about 5.4 bits/month at 185 holes each (resharpened). Over 12 months, the hole count is 12,000.

Strategy	Bits Used/Year	Unit Cost	Annual Tooling Cost
Buy new every time	60	$6.50	$390
Resharpen (5x per bit, then replace)	10 new + 50 resharpens	$6.50 / $2.80*	$205

*Resharpen cost includes $2.00 service + $0.80 amortized shipping

Year 1 savings: $185 on this one drill size. That's a 47% reduction in tooling cost for 3/8" bits alone.

Five-Year Projection: Single Drill Size

Extending the comparison over five years, assuming 3% annual cost inflation on new bits and stable resharpen pricing:

Year	Buy New (annual)	Resharpen (annual)	Annual Savings
Year 1	$390	$205	$185
Year 2	$402	$211	$191
Year 3	$414	$218	$196
Year 4	$426	$224	$202
Year 5	$439	$231	$208
5-Year Total	$2,071	$1,089	$982

Nearly $1,000 in savings on a single drill size over five years. For a shop running 10 different drill sizes at similar volumes, the five-year number scales proportionally.

Scaling to a Multi-Size Shop

Most production shops use more than one drill size. A shop running 10 sizes (say, 1/8" through 3/4" in common increments) with comparable monthly hole volumes would see:

• Larger bits cost more to replace — the savings per resharpen are higher in absolute dollars
• Shipping efficiency improves — sending mixed sizes in a single batch lowers per-bit shipping cost
• The aggregate five-year savings across 10 sizes: $8,000–$12,000 at this volume level

These aren't speculative numbers. They're the result of applying the same cost model across size ranges, accounting for actual tool replacement pricing from major distributors.

The Hidden Costs Not Yet Counted

The table above only counts direct tooling cost. There are secondary costs that favor resharpening further:

Procurement overhead: Every new bit order requires a purchase order, receipt, inventory check, and accounts payable processing. Some shops estimate $15–$40 in overhead per purchase transaction. Resharpening consolidates tooling service into fewer, larger transactions.

Inventory carrying cost: Maintaining a buffer stock of new bits ties up capital. A resharpening program with known turnaround times allows tighter inventory management.

Quality consistency: New bits from different batches may have subtle geometry differences. Resharpened bits from a consistent service restore to a known standard. On critical holes, that consistency has value beyond just cost.

When the Math Breaks Down

Resharpening economics don't always win. The cases where buying new is the right call:

• Small diameter bits (under 3/16"): The bit cost is low, the resharpen cost relative to replacement is higher, and small bits have limited resharpen life. At 3/32" and under, replacement is almost always the right answer.
• Cheap import HSS: A $1.50 bit isn't worth resharpening. The steel quality may not support multiple resharpens, and the service cost exceeds the replacement cost.
• Emergency situations: If you need a bit today and your resharpened stock is at the service provider, buying new is the right operational decision regardless of economics.
• Severely damaged bits: Bits with chipped lips, bent shanks, or excessive wear past the flute may not be viable resharpen candidates. Evaluate before sending.

Building the Resharpening Habit

The barrier to resharpening programs isn't usually economics — it's logistics. Setting up a process where bits get pulled when dull, batched, shipped, and tracked back into the crib requires some initial overhead. Once the process is established, it runs on its own. The key steps:

1. Define the pull point — how dull is dull enough to pull rather than run one more job?
2. Designate a collection point — a bin or shelf where pulled bits accumulate until batch size justifies shipping
3. Establish a turnaround buffer — how many bits need to be in the crib to cover production during resharpening turnaround?
4. Track the numbers — even a simple spreadsheet of bits sent, cost, and holes drilled builds the data to verify the economics hold

The five-year numbers are clear. Resharpening quality HSS bits at significant production volume reduces tooling cost by 40–50% relative to buying new — on every size above 3/16" where the math works. For shops not already running a resharpening program, the only cost is getting started.