Replacement blade checklist
HOW TO MEASURE SHREDDER BLADES.
A machine model is the starting point. Clear photos and controlled measurements help identify the exact rotor knife, counter knife or cutter disc before quotation and production.
Six-step review
Capture the geometry without guessing.
Clean the part and use calibrated tools where possible. Record units on every sketch, keep the blade orientation consistent and identify any surface that is already worn.
Identify
Record machine brand, model, serial range and the blade position in the cutting system.
Overall size
Measure length, width or outside diameter, plus the maximum and minimum thickness.
Mounting
Measure hole diameter, center distance, countersink, counterbore, keyway and bore features.
Cutting edge
Record bevel side, edge angle, concave or straight face, hook direction and tooth profile.
Photo checklist
Show every face and mounting feature.
- Front and back
Photograph square-on, not at an angle - All side views
Show thickness, bevel direction and edge profile - Close-ups
Capture holes, countersinks, bores, hooks, teeth and damaged areas - Scale and orientation
Include a ruler and mark rotation, feed direction or mounting position - Matching parts
Show the counter knife, spacer or adjacent cutter when fit depends on a pair
| Square rotor knife | Length × width × thickness, center hole, countersink or thread, face geometry and usable corners |
|---|---|
| Bed / counter knife | Overall size, hole pattern, slot position, bevel side, edge angle and mounting face |
| Cutter disc | Outside diameter, bore, thickness, hook count, tooth profile, keyway and spacer arrangement |
| Hook / tooth | Overall envelope, mounting geometry, hook direction, cutting radius and matching holder |
| Units | Use millimetres or clearly state the measurement system on every drawing |
Avoid common errors
Measure the original geometry—not only the wear.
A worn edge may be shorter, thinner or rounded. Mark worn surfaces, compare multiple blades when available and provide an unworn reference dimension wherever possible.
Cross-check
Compare several pieces, the machine manual or an approved historical drawing.
Add duty data
State feedstock, contamination, quantity, current material and the observed failure mode.
Send a sample
Use a physical sample when complex profiles or worn dimensions cannot be verified remotely.
Approve
Review the controlled replacement drawing and acceptance points before production.
Measurement FAQ
Useful information before quotation.
Photos help with identification; confirmed geometry protects fit and repeatability.
What dimensions are needed?
Record the overall size plus all mounting and cutting features. The exact points depend on whether the part is a rotor knife, bed knife, cutter disc, spacer or tooth.
Can a worn blade be measured?
Yes, but identify worn surfaces and avoid using a rounded edge as the original profile. A matching unworn part or machine drawing improves verification.
Are photos enough for a quote?
They can support an initial review, especially with the machine model. Final manufacturing dimensions should be confirmed from measurements, an approved drawing or a physical sample.