The pure carbide layer produced by the TDX Process is extremely hard. It is therefore very important that the surface finish of the tooling be smooth and free of all tool marks. Key points to be considered are surface roughness and polishing direction.
In all cases, the final finish on tooling details subject to moderate forming pressures should be 5-to-8 RMS micro-inches or better.
When forming coated, plated, stainless, or HSLA (High Strength Low Alloy) steels, the final surface roughness of the tooling should be between 1 and 5 RMS micro-inches or at a “mirror” finish.
Polishing should be performed after final machining in the wear areas or working surfaces. The detail should be polished progressively, using polishing stones ranging from 200 grit at the beginning to 1000 grit at the end. The tooling detail can be finished with a 5-to-7 micron diamond compound.
All tool and grind marks must be removed. If visible lines or scratches are present on the detail, it is recommended that the polishing direction be the same as the direction of the metal flow (see sketches below).