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09-29-2006, 04:59 PM #1
I would like to make a custom type of flat spring myself out of spring steel sheet, either 1074/1075 or 1095.
I checked couple places that sell it and it comes in either blue tempered or annealed.
I want to form or bend it in several locations to make the shape I want.
My question is can I bend or shape blue tempered spring steel (45 and 90 degree bends)?
If I buy annealed, it would be easy to shape but then Im guessing I would have to temper it? If so can the tempering be done at home? I have a welding torch and a little oven that gets to about 400 degrees?
09-29-2006, 05:32 PM #2
Blue tempered spring steel can be permanently bent by exceeding the yield strength. Bending causes tensile stress on the outside of the bend. You can reach the tensile strength of the steel if you bend with too small an inside radius. In other words, the part will crack or break. So the key is to bend with the largest possible inside radius.
You can bend the part while red hot to make it possible to do a sharp bend. Then you must heat treat the part as described below.
Heat treating the annealed stock requires first getting the part red hot and water quenching it. That is the hardening part of the heat treatment. Then you clean off the scale and temper it by heating at around 450-500 degrees F. to a uniform blue color and let it cool.
A Google will find you much more detailed information on heat treating spring steel.
09-29-2006, 05:57 PM #3
Thanks Larry. I might be able to get it to 500 degrees in my Barbeque grill with the propane.
I checked google and came up with very little. Mostly Stuff on knifes, not much on springs.
09-29-2006, 06:07 PM #4
Do you have a lead melter. does a great job on drawind springs back
09-29-2006, 08:54 PM #5
No David I dont.
What if I bring the spring to blue temper by using the torch? I have a temperature indicating crayon for 500 F. How long do I need to keep it at 500 F? I cant seem to find anything on the web, maybe someone can point out a link to a web site.
If I can get by with buying already blue tempered spring steel I would but it seems as though it will be hard to form and might break.
Does anyone know if its possible to bend around .025 1095 spring steel or .032 1074 spring steel already tempered in the shape of a V or Z or would that cause it to crack?
09-29-2006, 09:07 PM #6
Actually It needs to look like this. First the flat sheet 1" wide, then two bends( dont know the exact degree) then the circular bent.
Makes sense, I have to over bend all the bends in order for them to look like the final piece but would it break or be too hard to bend?
09-30-2006, 12:53 AM #7
I nade a full set of drawer latch springs for a small cabinet.
I couldn't get reasonable quantities of spring steel in teh right gage, so I got some feeler gage stock, and sheared it to size.
I had to bend an "eye" at one end, of a special shape, with two right angle bends, an open angle, and an over-90 bend. The other end had a rivet hole. Parts about 1/4" wide, 1 1/4 long in bent condition.
I annealed the stuff, then bent, until I had the shape. The reverse bend required a second anneal. Then all got hardened by heating over a gas stove flame and quenching, then drawing back to a purple-blue over teh same flame. (you use whatcha got)
I made about 20 of them, and they all worked out fine by that process, after the first couple experimental ones, which cracked in bending or in trial use.
From my experience, it will surely crack if over-bent in anything but annealed condition. Probably no way in blue temper condition. The stuff I used work-hardened fast, and would crack if at all hardened when bent past about 30 degrees.
You are right on the edge.... Do you require sharp bends? If not, might work. Sharp bends on teh "wings" will probably give up in use, if not in bending, assuming they get stressed.
You also may have trouble with even heating if you need to harden and temper. The part looks biggish, and has a lot of width. Be sure you need to heat-treat before you try it. Heating it with a torch will probably be hard to do evenly. Maybe you can get it to work in blue condition by radius bending.
09-30-2006, 10:58 AM #8
HELLO TO ALL,
years ago, a boss i was working for gave me
a job to bend 1095 flat stock. it was a radius
bend, but at 90degrees. i ask him if i should
try it cold, or heat it. he said try it cold.
i did, and it broke, so i had to heat it with
a torch to bend it. this was 1/4in thick material, and it was tempered.
you might try a bend, before you heat it, but
it may not work.
wright city, mo.
09-30-2006, 01:01 PM #9
Without some sort of oven or forge, you won't be able to get the spring evenly heated to quenching temperature, which is around 1450 degrees. It's too thin to hold the heat, unless you have a torch with a BIG heating tip. You might be able to put it in a large charcoal fire.
You could try retempering a very small area where the bends will be to reduce the hardness.
Tempering can be done over a stove burner or using a torch. Easy does it on this thin material.
09-30-2006, 06:32 PM #10
for tempering the lead bath is the best way to go.
if you have a cracker barrel resturant close by they have small cast iron pan that you can melt the lead in and make a hook out of wire or a metal coat hanger dip in the molten lead and count to 15 slowly.
you can get lead at a plumbing supply house.
the annealed spring material is best if you want to form a spring but i haven seen annealed spring in sheet material...jim
09-30-2006, 07:10 PM #11
The way I harden gun springs like that is to heat bottom of a 1/4 in steel plate with torch, set spring edgeways on plate, watch colors creep up spring to red /orange dump in oil. Polish then reheat to a Light to medium blue, pick off with pliers and dump in oil. Its a quick easy way to get even heat on an unevenly shaped spring.