slipjoint backspring

K

KenH

Well-Known Member
OK, I'm using Sandvik 14C28 for blades, and used it for a backspring. It broke - I was over stressing it a bit, but still broke. After tempering for 2 hrs around 850ºF it was still around 55Rc or so. I hoped for something in the area of 50Rc or so. Seems like I read or heard somewhere 14C28 wasn't the best option for backspring metal - true? Or not?

If 14C28 will work for backspring - would someone provide heat treating info please?

Would 440C be any better for backspring? If so, what heat heating/tempering info? I read on USAKnifemakers.com 440C for springs should be 1880ºF for 15 minutes, with a 1 hr at 1100ºF - does that sound about right?

Thanks to all for suggestions and guidance.

Ken H>
 
Ken,
Temper the 14c28n at 1040 for two hours. That will get you a 45 Rc without a sub zero quench,46 -47 with a sub zero quench,when I say sub zero I mean just take it to -5, no need for a long soak. You can do this in your refrigerator freezer.
14C28N makes an excellent spring if tempered correctly,your 55 Rc was way too hard,you should be 45 - 50.
 
Thanks Calvin - as I said in email to you, I remembered something on the tempering, but couldn't remember what temperature you'd said to temper at for a good Rc number. Thanks, now we've got it on forum and maybe I can find it again:)

Is there any real reason to sub zero quench the backspring? I always do the sub-zero quench for blades for it does seem to help a tad, but would that be useful on backspring?

Good luck at Guild show this weekend.

Ken H>
 
You must log in or register to reply here.
Back
Top