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Working with Blue Tempered 1095 Shim Stock

Engineeringtech

Aluminum
Joined
Oct 22, 2010
Location
New York
Ok, this is not a gun question, but I am making flat springs from 1095 stock and COULD be a gun question. I bought annealed 1095 flat stock, .025 thick for a project. No problem machining, hardening, and tempering the springs. But too strong. Need a thinner spring. Problem is, I can't buy anything thinner than .025" unless it is blue tempered. I can't drill it or bend it. A HSS drill won't penetrate. It breaks the cutting lips of a carbide drill. And even gentle bends crack the material.

I don't have a heat treating oven. All I have is a propane torch. I can heat the stuff up cherry red, and quickly plunge it into sand, but after it cools off, a file just glides off the stuff.

Am I not heating the stuff long enough? Or is it cooling to fast in the sand? Ideas?
 
Might Try This

Heat it up and let it cool slowly to anneal it.

After it is shaped, Heat very hot, quench in oil, then reheat in your oven to 500 to 600F or possibly in the self-clean mode.

Also, saw an old gunsmith do this. After the quench, put it in a small tray, cover with lighter fluid about 1/8 deep, ignite the fluid and let it burn completely.
 
Depending what you are exactly doing with it. Holes can be easily punched in 1095. If their small enough, a "Hand punch" works great.
 
I normally use 1075 or 1095 annealed spring steel and then shape and drill it to the required shape and size and then polish it to a mirror finish removing all milling and fileing marks. I then take it to cherry red in a soft flame and hold it there for about 30 seconds and quench in motor oil. I then re-polish to 600 W&D and then bring it back up to a mirror finish. I then heat it very slowly and evenly over a minute or so with soft propane heat till it makes dark blue and then drop it in oil to draw it back. I generally test them at that point and if they are two tough I grind them slowly without heating and then re-polish and install. Pretty much exactly the way I was taught in school. I'm the first to admit its a touchy, feely, practice thingy though. I had a lot of failures at first but I can't remember having one fail in the last 20 years or so. I generally always try to make them a bit to tough and then grind them.
 
Heat it up and let it cool slowly to anneal it.

After it is shaped, Heat very hot, quench in oil, then reheat in your oven to 500 to 600F or possibly in the self-clean mode.

Also, saw an old gunsmith do this. After the quench, put it in a small tray, cover with lighter fluid about 1/8 deep, ignite the fluid and let it burn completely.

Thanks. Not having any trouble hardening and tempering. It's annealing that is the problem, and I have no oven. But I like your idea using the lighter fluid to do the temper.
 
I normally use 1075 or 1095 annealed spring steel and then shape and drill it to the required shape and size and then polish it to a mirror finish removing all milling and fileing marks. ......

Do you know where I can get annealed 1095 less than .025 thick? All I have been able to find less than .025" is blue tempered, or 1075. I have hesitated making this out of 1075, because this spring needs to take a lot of cycles.
 
Put the thin piece between two pieces of thicker steel. Heat up the whole mass and let it cool slowly.

Thanks again. So you're telling me it is probably cooling too quickly in the sand? Or am I not heating the metal long enough. Your idea is good. I don't know why I didn't think of it. But that's why I come to these forums. Only problem is whether my puny propane torch will heat the chunks of steel up to red hot.

My employer lost some major contracts the past few weeks. Right now we're all wondering if we have jobs past the holidays. Money is extremely tight. I can't ask them for an oven.
 
Hi

If your propane torch can't handle it, no problem !

When brazing large copper/copper alloy items with such a torch it can be difficult to get them up to heat because copper , especially when blackened by the heat, is an excellent heatsink and radiator.

Solution is pretty much straightforward: Aerated Concrete, Ceramic wool, refractory bricks , anything that will guide the flame around the workpiece and retain a lot of heat. Also a working solution : Charcoal/Coke.
Not only is the stuff a bad conductor of heat, it helps generate more heat.

Combine both as required......

Answer to anybody mentioning oxyfuel in future replies:

Its expensive, its much more easy to damage the metal by overheating
(A problem on model boilers built by the hobbyist !) and its quite amazing how much work a big propane torch gets done when you use it wisely.
 
Do you know where I can get annealed 1095 less than .025 thick? All I have been able to find less than .025" is blue tempered, or 1075. I have hesitated making this out of 1075, because this spring needs to take a lot of cycles.

I'm curious about the reason you can't reduce the thickness of the 0.025 stock, or modify the profile to get the spring rate you're after.
 
After I heat treat a spring I never try to anneal and reheat treat it . It never seams to work all that well. I just start over. The last time I bought spring stock it was from Admiral Spring Steel supply in Illinois. I used to buy it from Brownells but I needed a freak size and called Admiral on a lark. They had what I wanted and it was quiet cheep. The salesman I talked to was a gun nut and after chatting for 1/2 hour I had a grab bag of assorted sizes to the total of about 15 or 20 pounds for a hundred and fifty bux. It seemed like a good deal to me anyway. I gave most of the larger stuff away to a knife maker friend and I still had enough left for a 10 year supply. I have only dealt with them once but I got the impression that they were sort of a metal supermarket of specialty steels. They were very pleasant and the shipping to Canada was quick and incident free. If that helps.
 
According to the heat treaters guide (2nd edition)
Normalize 1550 to 1570 F an cool in free air. (good solid red, starting towards orange)
Annealing, 1475 F and cool slowly, keep the cooling rate to about 50 degrees per hour.
Hardening, heat to 1475, quench in water, brine, polymer, oil for round parts under 0.19"
Tempering for your needs will be in the 300 to 900 F range. 300 for an hour should put you in the RC65 range, 900 will get you down to about RC45.

Yeh, Yeh, no furnace or other good way to measure temp.
The information is still valid and may help you understand the issues your experiancing.

RC65 or better can be achieved with this material, and thin parts can be quenched in oil.
Normalizing temperatures are rather high.
Annealing rates are SLOW.


Problems you may be having
1) not cooling slowly enough - sand is not much of an insulator. Try wood ash or clamping between two larger hot masses and then put into the wood ash.

2) Normalizing should get you soft enough to do what you need to do. Try getting the part a touch warmer and then hold it at temp for a few minutes. Then slowly play your flame away, forcing the part to cool over a period of a few minutes. With the amount of surface area you have on a flat spring it may have a high enought heat transfer rate to air harden to some degree.

Also, adjust your flame carefully. You want a neutral to carborizing flame, no extra O2, no extra carbon. 1095 has so much carbon, picking up a little from the torch will probably not be noticed. O2 will cause lots of scale and decarborization.

1095 is such a basic steel over heating is not likely to be a big problem, but watch it because the parts are thin.
 
For tempering after the hardening try melting enough lead that you can submerge the part in. Lead melts at 621F. Submerge the (DRY and Polished) part in the lead for at least 15 minutes but this will depend on the size of the piece. Pull out and quench. Another gunsmith friend taught me this and it has worked fine. I keeps you from over heating the piece.
 
mnguns technique of quenching in an elevated temperature bath produces an interuped quench cycle and results in an "austempered" part. These days its is normaly done in a salt bath, rather than lead. Some steels respond better to this than others. 1095 is actualy a good choice for austempering.

The process produces a different microstructure than the normal Q&T cycle.
The resuting structure is usualy tougher than an equivelant part quenched and tempered in the normal fashon.

The need for an extra hot tank for quenching has reduced its popularity in comercial applications.

The big down side to it is the lead vapor that is released for you to breath in.
Same problem with quenching in mecury or other liquid metals.

Good ventelation is needed if you take this approach.
 
Vermiculite or Perlite are better insulators than sand. Both should be available at a garden center.

You might get sufficient heat from an electric hotplate - about $20. at Walmart.
 
There is a short tutorial in the Brownells catalog about making springs. It's pretty simple and I have good success with it. it may also be available online. I bought a bunch of blue tempered spring stock from Small Parts years ago, I think it is .018" thick by about .5" wide in 18" lengths. I do believe they carried other sizes as well. They are expensive though. I have also drilled holes in the tempered spring stock using diamond burrs and a little spit to keep the spring cool.
 
I have not seen this mentioned yet. Instead of heating to cherry red and trying to do a slow cool down. Aim for taking most of the hardness out by heating your spring stock to about 1100 to 1200F. It will not be normalized or annealed but shoud be fairly workable and it will not matter how fast or slow it cools. I made a revolver spring that operated both the cylinder and trigger this way. Used feeler gage stock which I imagine is close to your blue stuff. Drilled a hole, slit about halfway with a hacksaw and bent the latch portion. Heat treated it as described already. It lasted for hundreds of rounds with myself and it was still shooting when the next owner sold it. I like the idea of thinning it from the side to adjust tension.
 
FredC,was that spring for a Navy Arms Scofield revolver? They have a weird spring that does both trigger and cylinder IIRC. Years ago,I reworked mine to get less of a trigger pull,and it was tricky getting it to work right.
 
GWilson, It was a no name .22 with an aluminum frame. Many years ago when my machine shop was a 9" South Bend in a screened porch. The one leaf spring operated both the trigger and the cylinder lock. It may have been more accident than skill that it worked so well. Main point here was tempering below the critical made the spring soft enough to machine and bend with no worries about about slow cooling.
 








 
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