Cassette Configuration
This configuration uses a simple cassette-style assembly that mounts between the drum and OEM clamp. The Key Knife clamp and counterknife are linked together for accurate clamping. Shim packs are used to adjust knife tip location. No modification to the drum is necessary.
Examples of drum chippers running this configuration: Bruks 820 and 1212 chippers

Holder Configuration
This configuration uses a holder to mount Key Knife clamps and counterknives between the drum and OEM clamp. This unique design allows for the use of an indexable counterknife. Shim packs are used to adjust knife tip location. No modification to the drum is necessary.
Examples of drum chippers running this configuration: Brunette 3230 & 6040 chippers

Holder configuration (for shallow pocket drum chippers)
This configuration is for drum chippers that have shallow pockets, preventing the use of Key Knife’s cassette and standard holder configurations. This configuration replaces the OEM clamp with a holder used to mount Key Knife clamps and indexable counterknives. Shim packs are used to adjust knife tip location. No modification to the drum is necessary.
Examples of drum chippers running this configuration: CBI 6400 and Bruks chippers