What regrinding actually restores

A worn blade has usually lost one thing: the edge geometry. The body is sound, the mounting holes are sound, the steel is sound. Regrinding removes a controlled amount of material from the cutting face until the original edge angle is back, then re-checks the dimensions your machine depends on.

What it does not do is put back material that has chipped away, straighten a blade that has bent, or undo heat damage. Knowing which of those you have is the difference between a blade that works after grinding and one that comes back the same as it went out.

What we can regrind

• Circular slitter knives — top and bottom, kept as a pair
• Circular knives and perforating discs — outside diameter and face
• Straight and long flat blades — mask machine blades, sheeter and trimming blades
• Guillotine and shear blades — single or in sets
• Granulator and pelletizer knives — rotor and bed knives
• Zig-zag and serrated blades — where the tooth form can still be reproduced

What we will not regrind, and why

We would rather turn down a job than return a blade that disappoints. These we decline, or tell you honestly that a new blade is the cheaper answer:

• Deep chipping that would take the blade below its usable section. Grinding it would produce a thin, weak edge.
• Bent or distorted blades. Grinding a bent blade gives you a sharp bent blade. The distortion stays.
• Overheated edges — blue or purple discolouration along the edge. The heat treatment is gone, and no amount of grinding brings it back.
• Coated blades where the coating does the work. We can grind the substrate; we cannot restore the coating.
• Welded, built-up or previously repaired edges.

How much can be removed

Every regrind takes material off, and that changes the numbers your machine registers against. A circular knife loses diameter, which changes the overlap with its mating knife. A flat blade loses thickness, which changes how it clamps. Both have a limit, and the limit is set by the starting section — which is why we measure before quoting rather than promising a number of regrinds up front.

One rule that saves a lot of trouble: grind the pair together. Regrinding only the top knife leaves you setting clearance against a worn bottom knife, and the cut quality rarely comes back. Send both and we keep them matched.

What comes back with the blade

• The blade, ground to its original edge angle
• A dimension sheet — outside diameter or length, bore, thickness and edge angle after grinding, plus the usable section left
• Matched pairs kept together and marked, so they go back on the machine in the same order

The dimension sheet matters more than it sounds. If the diameter has come down, your operator needs to know before the blade goes on, not after the first rejected roll.

How the process works

1. Send photos of the worn edge and the main dimensions, or the original drawing if you have it.
2. We assess the blade and quote — including whether regrinding is worth doing at all.
3. Ship the blades to us in Shenzhen. Inbound freight is on your side.
4. We regrind, inspect, and send the dimension sheet for your approval.
5. We ship the blades back to you as soon as you approve the dimension sheet.

Be realistic about the round trip. Cross-border freight and customs add time in both directions. Regrinding works well when you build a set of worn blades and send them together; it is a poor fit for one blade you need back this week. If downtime is the problem, keeping a spare set on the shelf is the answer, not express shipping.

Regrind or replace?

• Edge rounded evenly, no chips — regrind. This is the ideal case.
• Small chips inside the usable section — regrind, but expect a shorter life than a new blade.
• Deep chips, cracks or heat discolouration — replace.
• Already at the minimum section — replace. There is nothing left to take off.
• One half of a pair worn much faster than the other — check the machine before spending money on blades. Uneven wear is usually run-out, mounting or pressure, not steel.

Regrinding questions

How many times can a blade be reground?

It depends on the starting section and how much material the holder needs in order to clamp properly. We measure the blade and tell you the realistic number; anyone quoting a fixed figure without seeing the blade is guessing.

Do you regrind blades you did not make?

Yes. Send them for assessment. If we can match the geometry we will quote it; if the blade is at the end of its life we will say so.

Will the dimensions change after grinding?

Yes, and that is normal. Diameter or thickness comes down by whatever the regrind removed. The dimension sheet tells you exactly how much, so the machine can be set accordingly.

Can you regrind a coated blade?

We can grind the steel, but the coating will not come back. If the coating is what gives the blade its life, regrinding is usually not worth it and we will tell you before you ship.

Do you sharpen mask machine blades?

Sometimes. Those blades are thin, and grinding removes thickness that the machine may depend on. Send a photo and the thickness and we will give you a straight answer rather than take the job and return something that will not run.