Cutting tools are one of the most significant ongoing costs in any machining or manufacturing operation. And one of the most common questions we hear at SGSI is simple: should I resharpen this, or just replace it?
It sounds like a straightforward question. It isn’t.
The answer depends on the tool type, the material it’s made from, how worn it actually is, and what you’re paying for replacement versus sharpening. Get it right and you can cut your tooling costs by 40 to 60 percent. Get it wrong and you’re either running dull tools that destroy surface finish and break unexpectedly, or you’re throwing away money on new tools you didn’t need.
Here’s how to think through it.
The Basic Economics of Resharpening
A quality carbide endmill costs anywhere from $25 to $200 or more depending on diameter, flute count, and coating. A resharpen on that same tool typically runs $8 to $25. That’s a significant difference — and carbide can usually be resharpened 3 to 5 times before it’s truly worn out.
Over the life of a single endmill, resharpening instead of replacing can save you $60 to $400 per tool. Multiply that across a shop running dozens or hundreds of tools and the math gets serious fast.
The key is knowing when the tool is still worth sharpening — and when it isn’t.
Signs a Tool Should Be Resharpened
Cutting edge wear without chipping. If you can see the edge is dull — producing more heat, leaving a worse surface finish, requiring more force — but the flutes and body are intact, that tool is a prime candidate for resharpening. This is normal wear and exactly what resharpening is designed to fix.
Consistent geometry. A tool that’s worn evenly across all flutes can be reground to original geometry with high precision. At SGSI we use ANCA FX7 CNC grinders with ANCA CIM 3D software to reground tools to OEM tolerances — the same machines used to manufacture new tooling from carbide blanks.
Adequate diameter remaining. Each resharpen removes a small amount of material from the cutting edge, which slightly reduces the tool’s diameter. As long as the diameter is still within tolerance for your application, resharpening is viable. Most tools can handle 3 to 5 resharps before diameter loss becomes an issue.
HSS tools. High speed steel tools are almost always worth resharpening. HSS is less brittle than carbide, holds up well to regrinding, and new HSS tooling is expensive. If it’s not chipped or cracked, sharpen it.
Signs a Tool Should Be Replaced
Chipping or micro-fractures. Carbide is extremely hard but also brittle. If a tool has chipped cutting edges — even small chips — the structural integrity is compromised. Resharpening a chipped carbide tool can sometimes salvage it if the chips are minor and confined to the cutting edge, but significant chipping usually means replacement.
Catastrophic breakage. If a tool has snapped or broken mid-cut, it’s done. No amount of resharpening fixes a broken tool.
Excessive diameter loss. If the tool has already been resharpened multiple times and the diameter has dropped below your tolerance threshold, it’s time for a new one. Running an undersized tool causes dimensional errors in your parts.
Heavily worn flute geometry. Resharpening restores the cutting edge, but it can’t rebuild worn or damaged flute geometry. If the flutes themselves are heavily worn or deformed, the tool is past saving.
Cheap import tooling. Low-cost import endmills are often made from inferior carbide grades and aren’t worth the cost of resharpening. Stick to resharpening quality domestic or brand-name tooling — Kennametal, Seco, Sandvik, Niagara, Garr, OSG. If you bought a 10-pack of Chinese endmills for $30, just replace them.
A Note on Coatings
If your tools are coated — AlTiN, TiN, TiCN, ZrN, DLC — resharpening will remove the coating from the cutting edge. That’s normal and expected. Many shops recoat their tools after resharpening to restore full performance and tool life. At SGSI we offer recoating services in AlTiN, ZrN, TiN, TiLAN, DLC, AlCrN, and TiCN — matched to your material and application.
A resharpened and recoated tool performs essentially identically to a new coated tool, at a fraction of the cost.
The Decision Framework
Ask yourself these questions:
- Is the tool chipped, cracked, or broken? → Replace
- Is the diameter still within tolerance for the application? → Resharpen
- Has it already been resharpened 4+ times? → Inspect carefully, likely replace
- Is it quality carbide or HSS from a reputable manufacturer? → Resharpen
- Is it cheap import tooling? → Replace
- Is the cutting edge dull but geometry intact? → Resharpen
When in doubt, call us. We look at tools every day and can tell you in about 30 seconds whether a tool is worth resharpening.
The Bottom Line
Resharpening is almost always the right financial decision for quality carbide and HSS cutting tools that are worn but structurally sound. The savings are real, the performance of a properly resharpened tool is equivalent to new, and the environmental benefit of extending tool life rather than discarding it isn’t nothing either.
At SGSI we’ve been resharpening cutting tools for manufacturers, machine shops, cabinet shops, and food processors across the Midwest since 1976. We run 4 fully automated ANCA FX7 CNC grinders and turn around most orders within a week — with pickup and delivery within 100 miles of the Twin Cities.
If you’ve got a drawer full of dull tools and you’re not sure what’s worth saving, give us a call at 763.786.9652 or fill out our quote form. We’ll take a look and give you a straight answer.