43641- 45mm Shaft Mounting- Eccentric Locking Shear Holder 1.771 ID 4.13 O.D .375 Wide. This knife holder requires a keyway in the male knife shaft for locking. Locking is accomplished by rotating the holder while mounted on the shaft. This system will lock more parallel than set screw lock and will set up faster. This knife holder takes part number 12610 male knife blade