Rust on the joint

The rust on the hinge you describe is in all likelihood not rust, but our lubricating and preservative oil.

At the end of production, our tongs are processed with a clean clear oil. During this process, the oil enters the hinge and encounters soot. This soot comes from the quenching and tempering process. The hardening oil that enters the joint gap during this "quenching" burns there because of the high temperatures - soot remains. This is only a little, but because of the extremely narrow joint gaps, this soot is not completely washed out during subsequent washing operations.

If fresh lubricating oil now penetrates the joint gap, this soot is dissolved and the very fine particles turn the lubricating oil dark brown.