Surface decarburization


What is surface decarburization?

Because of occasional faults during the hardening of, for example, 8.8 or 10.9 screws, carbon may escape from the surface of the steel, thus rendering it unsuitable for hardening.

If decarburisation exceeds the reference values, the load-bearing capacity of the thread may decrease. This creates the risk that the thread will strip off during assembly or when a load is applied to the threaded joint. This critical aspect is rather difficult to quantify, and is therefore sometimes ignored by certain suppliers.

FABORY Group assesses the relevant manufacturers on their ability to prevent surface decarburisation. Moreover, FABORY Group's own laboratories use metallographic examinations to check if its products are showing signs of unacceptable decarburization.