How to temper TRS springs?

[jsn]

I am waiting on my lock castings to arrive, Watching for the big brown truck like a hawk,

I am wanting to know how to temper the TRS springs for the lock, I plan on using oil to quench but how do you temper the springs?

They say heat to 1500 degrees quench then reheat to 700 and let sit on a plank to cool? Is this effective and correct?

Please no arguing on which way is best, ill choose which method is best for me.

Just asking methods on how to do it....

Thankyou for any help, it is much appreciated!

 

[bioprof]

You have to first harden it by heating to cherry red and quench in light oil like transmission fluid. You then have to temper the spring so that it won't break. The easiest way to do this is to put the spring in a tin container with just enough motor oil to cover the spring. Heat up the oil until it starts boiling and then light the oil. When the oil burns down to the spring it is done. Clean it off and you're ready to go. I've done this and it seems to work.

Some people temper the spring by immersing it in melted lead. I've never tried it but it is supposed to work.

 

[jerrywh]

Depends on what you have for equipment.
If you have a furnace , heat to 725 for 20 minutes to temper. .
If you don't harden the spring as you described then put it on top of yuor lead pot and melt the lead. As soon as the lead is all melted turn off the heat and hold the spring under the lead until the lead sets up. Then reheat and when the spring comes floating to the top remove and let cool naturally.
The spring has to remain at tempering temp for 20 minutes. Some guys put the spring in a lid full of oil and heat the oil until it catches on fire. Then let the oil burn until it is burned up.
You will get a lot of argument on the last method. It is only about 70% reliable but many will argue that point. mostly because they got away with it a few times. When I started making guns one way I had of making extra money was making V springs for double shotguns for other gunsmiths. I made them by the dozen. The time factor is very important. Steel is a lot like cooking a bisquet. you can't just get it up to temp and then quit. It has to have time to get done on the inside. It takes time for the temperature to penetrate the total thickness . The rule is 20 minutes for each 1/8" of thickness.
so if you use the oil method be sure there is enough oil in the can to cover the spring. And use a high temp flashpoint oil. all oil does not flash at the same temp. You want a hot one. Look up flash points of different oils.

 

[J.D.]

I've had the best luck with SLOWLY heating a spring to a coupla shades past bright cherry red to almost a light orange, in shaded light. Let soak a bit and quench in canola oil. Temper in a lead bath, as instructed by Jerry.

I haven't made all that many springs, so I'm probably not the best person to offer advise. However, this is what has worked for me.

If you want to give yourself a little extra insurance, once the hardened and tempered spring is cleaned and shined up a bit, play the torch over it to SLOWLY bring the color to an even bright blue and let it cool naturally.

I don't know what the extra step does to a spring, but it seems to make 'em last longer while providing a good snappy spring. The blue is pretty too. :grin:

Oh, and wrap a stout wire around the upper leg of the spring, near the boss that rests against the bolster of the lockplate. Keep the wire away from the bend.

God bless

 

[jsn]

Soo basicly when I do this I should do it to all springs at one time right? and will a tin pie pan work or is that too dangerous?

In the oil burning thing do I let all of the oil burn away? or stop when its at the upper edge of the spring?


Will canola oil work since it's flash point is 620 degrees?

 

[Zonie]

The temperature for tempering a spring varies between 580 degrees F and 750 degrees F depending on the steel.

The 580 degree temperature will give the spring the same deep blue color that one often found in old clocks. The higher temperatures will leave the spring with a gray color.

Because there is quite a wide range of temperatures and the correct one depends on the type of steel the spring is made from I would use the temperature recommended by the maker or supplier of the spring.

If they said 700 degrees F then the answer is 700 degrees F.

 

[dyemaker]

I had these links for a simple forge. I don't know if it is what you need or not but it may be useful. http://www.philsville.co.uk/phillyforge.htm
and another http://www.cianperez.com/Wood/Wood...pages/PatrickRock_BuildingBlacksmithForge.htm

 

[matt denison]

"If they said 700 degrees F then the answer is 700 degrees F."

Thank you Zonie, :bow: I was holding my breath hoping someone would remind him what the manufacturer said. They know what steel alloy they use and how to harden/temper it. However the methods used to achieve those temps. can vary.

One tiny bit of advise: if you use the lead pot idea use a lead thermometer to see how hot the lead actually is. I once saw a fellow do a demonstration of this method and as he was talking to the crowd I watched the thermometer go up to 1,000 + degrees. When he cleaned the spring and put it under preasure it squished and stayed that way. (took a set) Had to start all over again, ruined his seminar.

 

[Stophel]

I just temper by heating to proper color. Much simpler and less messy than melted lead or burning oil! :grin:

 

[grey8833]

Have done several lock springs. Heat (MAPP) to critical - could never do the color thing so I use a magnet. When the steel goes non-magnetic (somewhere around straw color?) you hit critical and then you put to an oil bath and swirl. Wife yells at you for the stink (somehow I always do this in winter - too cold outside). Then I get out my Lee lead pot, wrap the spring in tin foil and push into a 600 degree bath (Brownell spring steel blanks). I use my lead thermo to make sure it is at 600, wait 20 to 30 minutes, fish out the spring, and set to cool. Make ball with the nice hot lead till the spring cools, unwrap and away you go. Kit Ravenshires (?) V-spring book is a good source. Spring comes out a beautiful blue black. Polish the main turn and oil. Works quite well.

Mike F

 

[jerrywh]

It's a good idea to use a lead thermometer. That makes it nearly fool proof. Remember the 20 minute rule though.
I tempered springs using the color method for about 6 months. about 30% to 40% of them broke from being too hard. When your forging them by hand that’s not fun.
All the gun part casters I know of are using two different steels. One is 6150 the other is 1095 it is possible to get a spring made out of 01 but you only need one formula for hardening and tempering because the process is so close to identical for all three types of spring steel that it doesn't matter.
I used to have sets locks cast for kits. Before that I forged all my springs from 1075 or 1095 carbon steel.
If you choose to temper by the color method I recommend buying your springs three at a time.
A tuna fish can is plenty big enough for a main spring on a long rifle with oil covering the spring.
Think about this-- If an oil has a flash point of 450°F the oil can't get any hotter than that because if it does it vaporizes and burns. The flame from the oil is about 1500°F. As the oil burns down to the point where it exposes the spring the spring gets hotter because the cooler oil is not sufficient to keep it cooler. At some point the temperature of the cooler oil and the flame temperature bring the spring to the proper temp. You need to guess at that but it's better to be too hot than not hot enough. You can't do much about a broken spring but you can reharden and retemper a soft one.
550°F is for clock springs not V springs. It's OK for coil springs like GPR has.
Mike F--- you must have some tin in your lead. Lead doesn't melt till 621.5°F
You guys make sure you have pure lead unless you have a lead themometer.
Maybe if I wrote a book I would be more believable. Try the machinists manual.

 

[LRB]

The TRS springs are 6150 chrome vanadium steel. From what I found, 6150 is oil hardened at 1550°to 1600°. A spring temper, as in a V spring would be tempered from 800° to 900°. The vanadium allows the higher hardening temps as it ******* grain growth, and the chrome vanadium combination requires the higher than normal heat to go into a homogeneous solution with the iron and carbon. That's according to printed specs. However if Jerry has had good luck with his method, it is hard to argue with success. This is a classic example that all steels cannot be heat treated the same, and get the desired results from each.

 

[Stophel]

I have been tempering by color for years now, with no problems.

I HAVE actually had a problem getting TRS springs to properly harden, though.

 

[Roy]

I do them by color too..

 

[jsn]

So basicly I can just temper them at 1600 degrees and polish like they say then heat to the scarlet color they suggest then just set it down on a board like they say and that may work?

The frizzen ill harden to 1600 degrees and then cook in oven for an hour or 2 at 400 degrees, Does that sound reasonable?

 

[LRB]

If you don't have an oven just bring them up to orange and quench. As far as temper, 400° would be a good start on the frizzen. That is a poor choice of steel for a frizzen. Not enough carbon. I don't know what to tell you on the spring temper. At the recommended temper, there will be no color. It would go neutral. I would suggest Jerrys method with the molten lead.

 

[jsn]

would quenching in used motor oil help with carbon issues?

 

[jerrywh]

It is true that TRS recommends tempering their springs at higher temperatures. Like 800 or higher. However I have found that the 6150 springs tempered at that temp seem too mushy for me but it works. I suspect they have recommended the high temp to insure that they will not be too hard and break because a lot of the people they sell to don't know what they are doing and forget the time factor or are never aware of it to begin with. By the way. 6150 is a very forgiving type of spring steel. That’s why they use it. That may be why so many people get away with so many mistakes. Chamber’s springs are either 1095 or 01 spring steel. That’s not as forgiving. I think L&R uses 6150. At least it acts like 6150. I reshape a lot of them.
725° is a good temp if it is held for 20 minutes. I never had one break for 45 years.
The reason some people have trouble hardening 6150 is because it only has 50 points of carbon and doesn't get as hard as the higher carbon steels. Never go higher than 1550 or 1600 in an attempt to get it harder. You might just end up with cracked spring if you do.
In 1961 I hired a metallurgical engineer to tell me what I was doing wrong when I heat treated springs. The answer was the time factor. I tempered them by color to 625°F and then let them cool naturally. Like I said about 30% or more would break. After I learned to hold the temp for 20 minutes I had no further trouble. Then about 15 years ago I built a furnace with pyrometer and went to 725°.
Way back in the 50's most of the books I could find recomended 625° I later decided that was a little risky I think I got the 725° from Jim Chambers.

 

[Zonie]

So basicly I can just temper them at 1600 degrees and polish like they say then heat to the scarlet color they suggest then just set it down on a board like they say and that may work?

The frizzen ill harden to 1600 degrees and then cook in oven for an hour or 2 at 400 degrees, Does that sound reasonable?

I'm betting you didn't mean to say, "tempering them at 1600 degrees". 600-700 would be closer to the ball park.

A scarlet color indicates a temperature of about 1300 degrees which in my opinion is too cool for the hardening temperature.

To harden the spring it should be a very bright red approaching a orange color. It's hard to test but at the correct temperature the part will be non-magnetic.

When the part reaches this color keep it at that temperature for a minute or so. Then drop it directly into the oil quench.
You don't want to take any time getting it from the red/orange temperature into the oil because if it starts to air cool the steel will not harden fully.

After the oil quench the part will be VERY hard. Do NOT bend it or it will break.

When the part cools you may want to test it to make sure it has hardened. Do this with a flat file. The file should skid across the hardened part barely leaving a mark of any kind.

Once this hardness is achieved then get to work tempering the steel.
As I said before, if they recommend 700 degrees then that is the temperature to use.
Let the part soak at this temperature for 20 minutes or more. Then let it air cool to complete the tempering operation.

Have fun. :thumbsup:

When I said 700 degrees I was speaking of the spring. The lower temperature would be about right for a frizzen because you want it to keep much of its hardness.

 

[ohio ramrod]

I temper my springs by wrapping them in aluminum foil and then putting them in an electric pot filled with lead and set as low as I can get it and still keep the lead melted. :hmm: :hmm: