Hardening & Tempering
The two halves of the cycle
Hardening sets the maximum the material can reach. Tempering decides what you actually keep: a low tempering temperature holds most of the hardness for wear resistance, a higher one gives up hardness for impact strength. The tempering temperature is chosen against the hardness your drawing specifies, not against a house default.
Quenching
Quench severity governs both the hardness achieved and the risk of cracking and distortion. Our oil quench tank holds 30,000 litres, which matters because a large charge dropped into a small tank raises the oil temperature and quenches the last part differently from the first. Volume is what keeps a batch consistent from end to end.
Size is rarely the constraint
The gas-fired box furnaces take work up to six metres long, and the pit furnaces take a metre and a half of vertical section, so long shafts and large rings are handled without splitting the batch. Overhead cranes rated at five tonnes serve the floor.
Common questions
What hardness can you hold?
The achievable range depends on the grade and section. Give us the specified hardness and the material and the cycle is set against it, then verified on the treated part before dispatch.
Will my part distort?
Any through-hardening cycle moves material to some degree. Fixturing and load orientation are planned to control it, and telling us the critical dimensions at enquiry is what lets that planning happen.
Do you supply a hardness report?
Yes. Every batch leaves with a QA report and certificate of conformity tied to its job card.