Question on tempering

Blacksmithing General Discussion
1

Hello I’m fairly new to Blacksmithing and I hope no one minds me asking, but I figure this is the best place to ask.

I was just wondering if there is a reason my knives keep breaking when I test them? I have done everything possible to ensure a good quench and temper. I’ve even used a microscope to look for cracks before going into a quench. I temper my knives with blue on the spine and straw yellow on the cutting edge. When I went to test the flexibility of my latest knife by pressing down slightly on the middle my knife broke.

I am just wondering what I am doing wrong. I was using a file at the time that wasn’t case hardened for my metal. The knife was about seven inches long and one inch wide. the only thing that I didn’t take much care to do was check if the metal was non magnetic before going into the quench, however because the color was orangy yellow I knew the knife was none magnetic or above.

I would deeply appreciate any suggestions or pointers on where I’m going wrong or things I can improve so as to get the best quench and temper that I can.

2

Multiple tempering is preferred when differential tempering is used. This will overlap and create a more uniform temper.

3

Thank you so much for the response!

How would I go about doing a multiple temper?

4

just redo your temper three or four times, its supposed to relax the fractures that you get when you quench,try preheating your quench oil so that it cools down a bit slower so that it doesn’t go so brittle. hope it helps:+1:

5

Ok, thanks again! I’m new here so thank you for replying to my question

6

I think adding some copper will make it stronger