An embrittlement relief treatment in which electroplated or acid-cleaned parts of high hardness are held at about 190 to 220 C for several hours, starting within a few hours of plating. The heat drives absorbed hydrogen out or traps it harmlessly before it can cause delayed cracking. Baking lowers the risk without removing it, which is why many specifications ban electroplating on the hardest grades altogether.
Plating has to bake the 12.9s within four hours, so don't let that basket sit on the dock overnight.
Also heard as
- embrittlement relief
- relief bake
- de-embrittlement bake
Related terms
Hydrogen embrittlement
Delayed brittle cracking of hard steel fasteners caused by hydrogen absorbed from plating, cleaning or corrosion.
Zinc plating
An electroplated zinc layer, usually with a clear, blue or yellow passivate, the cheapest common fastener finish.
Quench and temper
The hardening heat treatment behind strength-grade bolts: heat, quench rapidly, then reheat to toughen.