Stainless Liner Question

colu41

colu41

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Dec 24, 2014
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So I'm needing a little info on this when the time comes. I bought a 3x24 sheet of .062" 410 stainless from knife kits for the liner lock blades I'm going to make. The thing that is confusing me is the spring tempering. Here is knifekits heat treat instructions:
Heat Treat Instructions:
For creating spring temper: We recommend an atmosphere furnace, or foil wrapping the steel to stop decarbonization. Austenize at 1800-1850° degrees F. for 5-10 minutes, or until the material is heated completely. Then air cool with a fan, or quench press, until the temperature is under 110° degrees. Temper twice at 750° degrees for two hours, allowing cooling between cycles to less than 110° degrees F.
NOTE: Heat treat results may vary with the oven and operator. We recommend 38-45 RC for best results.

If the liner already has the lock bent, how can you plate quench it after hardening? Or do they mean something different by quench press? Could I just blow it with compressed air? Any tips on this would be great.
 
I have two suggestions for you. Use titanium for the liners and don't bend your leaf until all work is done including the installation of the detent ball. Just hold the leaf over into the blade cut out to see how its holding.
Frank
 
Ok. Sounds good thanks. Can I ask? I know titanium is simply awesome all around, but for being my first couple folders will stainless not make a decent liner lock? Knife kits sells this 3x24" sheet for liners and clips. Just curious.
 
Not in my opinion and especially for the first ones. Having to do a east treat on that liner can be a big deal whereas with titanium you choose the thickness and then just bend it. I like about .050 for most of my liner locks but will use thinner or thicker to suit the knife size.
Frank
 
colu41 said:
Interesting. I take it titanium is rough drilling and grinding?
Click to expand...



It's easy to drill with premium quality bits, and grinding is easy if you follow one simple rule: slow belt speed with high pressure. If it's sparking, you're running too fast, and you'll run risk of getting sick from the fumes and/or starting a fire.


I ground 30 titanium scandi ground blades for a customer two weeks ago with *1* cubitron 984F belt, after that the belt was still sharp and I ground a couple of hardened stainless pocket knife blades with it.


I've got the 2x jumper set on my VFD, and running a 6" drive wheel, I run the grinder at about 30% speed to grind Ti.
 
This info is from USA knife making supply and when I use 410 stainless for liners it works very well for me. I do it after the lock bar has been cut but before it has been bent so that I can clean it up easily. 410 stainless has the advantage of not being sticky like titanium can.

410 Stainless steel is used commonly in liners for folding knives. The advantage to 400 series stainless is that is can be hardened. It is slightly magnetic.

Tip: To harden bring it to non-magnetic temperature and then cool rapidly under a fan. This is really simple with a small piece cut to size and using a small MAP gas torch. Heat it up until a magnet doesn't stick any more and then cool it off. It will pick up 5 or 6RC hardness. Usually, 400 series stainless doesn't get much harder than mid 40's so don't expect it to blade hard. The idea behind this is to give your folder just a little more stiffness.
 
Alan Davis Knives said:
This info is from USA knife making supply and when I use 410 stainless for liners it works very well for me. I do it after the lock bar has been cut but before it has been bent so that I can clean it up easily. 410 stainless has the advantage of not being sticky like titanium can.

410 Stainless steel is used commonly in liners for folding knives. The advantage to 400 series stainless is that is can be hardened. It is slightly magnetic.

Tip: To harden bring it to non-magnetic temperature and then cool rapidly under a fan. This is really simple with a small piece cut to size and using a small MAP gas torch. Heat it up until a magnet doesn't stick any more and then cool it off. It will pick up 5 or 6RC hardness. Usually, 400 series stainless doesn't get much harder than mid 40's so don't expect it to blade hard. The idea behind this is to give your folder just a little more stiffness.
Click to expand...
Thanks for this info. If I use my oven (with foil) should it be done at about 1450F-1500F for 5 minutes or so? I assume plate quench is fine.
 
Lo/Rez said:
Thanks for this info. If I use my oven (with foil) should it be done at about 1450F-1500F for 5 minutes or so? I assume plate quench is fine.
Click to expand...

Heat to between 1750 - 1850ºF When plate quenching I always blow air as well between the plates.
 
Take this with a lot of salt, there are more sophisticated ways to do this, but....
I did my first couple dozen stainless liners by bending the lock spring tab and then heating just the bent part to bright orange, then air cooling.
It picked up quite a lot of springiness, a little hardness, and I didn't have to correct distortion, caused by heat, in the part that needed to stay flat.
They're all still working great, springing and locking.
That said, when in doubt do it right- Ti is an ideal material for liners.
 
what temp and for how long should it be tempered at? 750F for 2 hours x2 sounds like to much for a liner, or is it?
 
410-Typical.gif
 
Thanks for the info. Would you recommend 400F to keep it as hard as possible? I'm not sure what properties are advantageous (or desired) for liner locks.
 
I talked to the metallurgist from Rolled Alloys today regarding the heat treat of 410 SS. He looked in an old military reference book and came up with (for pieces smaller than 1/4") 1750F-1850F for 35-50 minutes and one temper at a minimum of 1 hour. FYI in case anyone is making a liner lock.
 
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