So I couldn't readily locate specific spring steel so I figured I would try what I had on hand. I took the coiled spring off of a linchpin on my tractor and decided to try that. After straightening the spring I cut it to approximate length of 1.81 inches which in layman term for me came to 1 inch and 9/16, then used my dremel to round each end and it didn't work so I looked at an old buck 110 with a broken blade to see how there spring worked, even trying it but again it didn't work but when I put the buck spring back in the knife I noticed how it slide into the notch. So I decided to bevel the edge of my spring and after three tries it did fit in the recess and actually does work, at least for now maybe for good. Time will tell. Oh and lucky for me the linchpin spring was the correct thickness. I didn't have any stainless stock to replace the back spring pin with so I used brass.