Cardboard cutting tool - is hardened by HF in chamber filled with protective gas

摘要

In mfg. cutting and scratching tools to work paper and cardboard and mark out cutting section lines, the cutting and scratching edge (12) is partic. hardened by heat to a required temp., by passing it through a HF zone, so that the area to be hardened partic. is heated for a sufficient time. A controlled atmos. of protective gas prevents tarnishing and sparking. ADVANTAGE - The tool is produced simply and inexpensively, giving a cutting edge with a long life to execute a clean out.