I have been doing heat treatment of peoples' blades for several years now. I can heat treat the most popular steels such as D2, Niolox, N690, Damsteel and a few more. If you have a blade steel not on the list, ask me and I can tell you if I can do it or not. I can also do folder springs as well in a variety of steels.
The heating is done in my digitally controlled Evenheat oven and quenched in liquid nitrogen if the steel needs it. The cost is £8 per blade for blades up to 200mm long and an addition £1.20 per 25mm above that up to 350mm long I now only heat treat air hardening steels and no longer heat treat oil or water hardening steels
The cost includes signed for return UK postage. The service also includes straightening the blades post hardening, a service few large commercial firms can offer. Turnaround time is typically 3 weeks or less.
Please contact me for further information.
Disclaimer: I am not responsible for loss or damage to blades/springs sent to me for treatment.