View Full Version : heat treating engraved blades

02-10-2011, 07:20 AM
I am currently involved in a project with Mr Riccardo which will require that the blades for the knives be heat treated after engraving. This is something I have never done before. Do I need to send the blades out to someone who heat treats iin a vaccuum and if so who would you recommend? How is oxegen free heat treat different from heat treat in a stainless envelope? What do the blades look like after coming out of an oxegen free heat treat?
So many questions, thank you for your patience.

Bruce Bump
02-10-2011, 09:26 AM
Hi Steve,
I'm guessing the steel is high carbon non stainless? Some heat treat shops purge their electric ovens with argon gas which displaces the oxygen. I make gun parts that are finished to 400 grit and coat them with PBC from Brownells. You should test a scrap piece first if you're going to try it yourself. PBC needs to be put on at a higher temp than the directions on the jar. I preheat to 700-800 deg. and sprinkle it on and watch it melt and cover the entire surface. If it still shows shiney spots I re-heat and give it another coating. If it doesnt cover the blade completely there will be some pitting, thats why I think you should practise first. After the quench, the PBC rinses right off with hot/boling water in huge flakes and leaves the same 400 grit finish with only slight discoloration.
Salt bath heat treatment will work also if you have a salt pot system.
Hope this helps somewhat.

02-10-2011, 08:12 PM
I guess I forgot to mention that these are 440C blades. Does that make a difference in the oxegen free heat treat?

Bruce Bump
02-11-2011, 06:52 PM
OK, that makes a big differance. You can send it to Paul Bos Heat Treating. They deal with stainless on a daily basis and your blades will come back almost as pretty as when they went out. If you have a digital oven and stainless foil you can do it yourself. I paint the entire blade blue with dykem blue layout fluid and double wrap them to absorb any oxygen that will cause de-carb.

07-07-2011, 06:04 PM
do you still have to clean the engraved area out at all? or just sand down the flats and go.