heat treating engraved blades

SVanderkolff

Well-Known Member
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.
Steve
 
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.
 
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I guess I forgot to mention that these are 440C blades. Does that make a difference in the oxegen free heat treat?
Steve
 
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.
 
do you still have to clean the engraved area out at all? or just sand down the flats and go.
 
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