Folder spring question

[John L]

I normally use 0-1 and D-2 for my folders and am going to try a few new steels such as M4, 1095, and 440C. Do all of these steels make suitable springs if heat treated properly? Do some makers use one steel for the blade and another for the spring? I normally take the springs to R49-50. Thanks for any info.

 

[STR]

I asked Bill Ruple about this once and he said he uses the same steel as the blade for the springs in his knives. I think you can give any steel a spring hardness. Stainless to stainless shouldn't make much difference though. I don't think I'd mix carbon steel and stainless but I know some that are done that way. I read somewhere that it can lead to finish differences and other issues but couldn't find it before posting.

STR

 

[Dan Zawacki]

I can't speak intelligently on the spring issue, except to say that most steels with which I am familiar, once hardened and tempered would be suitable for SOME spring applications. The modulus of elasticity doesn't change to any really noticeable degree from one steel to another, so a thin enough cross section would be bendy whether it was 5160, 01, 440C or anything else.

I can say that two steels that are different enough from one another could look noticeably different once polished. Some steels seem to just "take" a polish better than others. If you were to look at one then the other, you might not see anything different, but put them directly side by side, and the difference can be fairly obvious.

 

[mete]

I don't think M4 is suitable for springs but 1095 and 440C have often been used for springs.A hardness of 50 HRc is ok but make sure the spring is polished -no scratches to start failures !