I have some spring stock from brownells. Need to make a flat spring for uberti.
After shaping the spring to what I need how do I heat treat it?
Thanks Ed
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I have some spring stock from brownells. Need to make a flat spring for uberti.
After shaping the spring to what I need how do I heat treat it?
Thanks Ed
Heat it in dim light till red. Let it cool down some then put in a shallow tin can and cover with motor oil. Burn off the oil outdoors, let it cool then check it in the vise to see if it's a spring.
Good luck.
Heat until Cherry Red,Quench in Oil,at this stage it will be Glass hard and will break if flexed.Clean off scale until the metal is bright.Now hold the spring in a flame until the metal is blue then Quench in Oil immediately.Spring Making can be heartbreaking so why not make up a sacrificial spring to practice on.Try not to have any lateral file marks on the spring these can be weak spots.Any bending or tweaking must be done with the metal red hot prior to tempering.
Critical temp is easily determined with a magnet,pref one of the new ceramic ones......heat a few secs beyond non magnetic,quench in oil,or you can use 1" oil on top of water.....If you cast ,an accurate temp for drawing is from your pot,hold the spring under lead for a couple of minutes,but preheat first.....cool slowly after drawing.............follow any instructions from Brownells,though.......incidentally,an old trick for making small,trigger type springs is to quench in a potato.Draw if necessary in lead......alloy steels need a higher temp than carbon,and may burn if you arent careful.
Do not let cool, then thrust into oil and swirl around to cool. Burning off the oil later may work. The post just before mine(#5) is a better process.Quote:
Originally Posted by Texas by God
Something not mentioned in the other posts, with a flat spring plunge it into the oil end first. Putting it in edgewise or flat will cause it to warp. It will curl toward the side that is cooled first.
Drawing more than once will improve toughness.......some steels need drawing for a considerable time....15-20 minutes.........remember all the transformation take time.
Texas by God has it right,I burn the Oil off twice watching the Spring go dry each time and drop the Spring into a can of Oil.Very much like his burning off in a metal tray.
Making a coil is easier . . . lasts longer.
Mike
Heating it dull red and allowing to cool slowly is the method for annealing spring steel. Letting it cool in warm ashes or on a less conductive surface than metal and covered with a can lid, may be the best way of getting it annealed really soft. In this condition you can safely change the shape of a thin spring, up to a point, by bending.
To make the spring glass-hard, you need to make most steels cherry-red and quench them as quickly as you can. Plain high-carbon steels need to be quenched in water, but many tool steels are designed to harden with the gentler quenching action of oil. Mild steels won't harden at all, and really high-carbon ones such as the 1095 used for knives and razors, may be stay a little too hard and brittle. You will hear of people quenching steel in strong brine, which will harden deeper inside a bulky object, but is unnecessary in a gun spring. There are hundreds of perfectly good gun springs lurking inside every automobile leaf-spring, ready to be liberated.
You don't need alloy steels for springs, and some are bad for the job. O1 isn't bad, but is unnecessary. It will quench effectively from slightly lower temperatures, making them less liable to distortion. (That is often called 01, with a zero, if you are searching on the internet, but it should actually be the letter O, for oil-hardening, while many good spring steels have a name with, appropriately enough, W.)
The hardened spring must be part-way annealed (aka "tempered") to make it usable. You must brighten the surface if you want to do this by watching the colours, and a fine diamond hone is good for doing this withough the kind of pressure that risks breaking it. Heating a hardened spring in a flame until it is a beautiful royal blue is indeed very good, if you can do it. But it is very difficult to heat a complex spring just the same amount all over. It will bend where it is pallid, and break where it is only brown.
A better way (for which it needn't be bright, but must be scratch-free) is to barely cover it with motor oil or similar in a shallow vessel, such as a dent hammered in a large can, ignite the oil outdoors with a torch, and let it burn away. The spring will end up greyish and filthy, but they have always worked for me. Doing a similar sized piece of steel at the same time, for torture testing, is indeed good advice.
If you particularly want your spring to be an attractive blue (or sears and hammers to be an attractive purply-brown), you can do this secondary heating in a bath of slowly heated sand to keep the colour even.
If you find you have made all or part of your spring too soft, you can reharden it and repeat the process. What you can't reverse is "burnt" steel, caused by heating it much beyond the colour of a cherry as usually constituted, for the initial hardening. The more the carbon content, the easier it is to do this. This colour needs to be judged in ordinary but not bright room lighting. Orange to yellow heat can look fine in sunlight, but isn't, and anything looks brilliant in the dark.
Ballistics, that's the same way I have been successfully doing it for years. That burning oil trick usually works great and is about as simple as it gets although there are of course many ways to accomplish the same thing such as tempering in molten lead as long as this is done with controlled heat. As for car springs, I have a bunch of the wound (coiled?) flat springs from car/truck window mechanisms that I have found to be extremely useful, these are already the right size for a lot of projects and can easily be thinned, bent or shaped to about any need necessary. Annealing this material and re-hardening is as simple as any material I have used, not sure what the alloy is but it's good stuff for sure and easy to get.