I have exhausted what I know....

[sussexmuzllodr]

Made many springs for the main spring in my Liege pistol. Used Dixie 1075. Did the usual shaping and forming. Heated red hot...oil quench....failure too soft. Tried red hot ...into cherry red....reheated to cherry red quenched in oil. Failure. No matter what I have tried it has failed. Mind you I spent hours duplicating the factory spring down to the very same dimension. they all came out too soft to give the proper snap of a spring...even the dixie steel. Where am I going wrong? Am I missing a step or process? I know some of you make springs without a hitch. Input is appreciated. If you could give insight PM me.

 

[Phil Coffins]

I use light oil heated to 150 degrees to quench. My oil is a large container so I can fully plunge into.

 

[44Bro]

Not hot enough. Heat till non magnetic, then quench, reheat to ~750F and let air cool. Should work first time.

 

[dave_person]

Hi,
Make sure the to heat to bright red even close to orange and try quenching with canola oil or a couple of inches of canola oil floating on top of room temp water. 1075 steel has to cool quickly and motor oil may not cool it fast enough. I learned that fact from LRB on this forum. Canola and quenching oils will do better. If you still have problems send the spring and lock up to me and I will heat treat it.

dave

 

[sussexmuzllodr]

Hi,
Make sure the to heat to bright red even close to orange and try quenching with canola oil or a couple of inches of canola oil floating on top of room temp water. 1075 steel has to cool quickly and motor oil may not cool it fast enough. I learned that fact from LRB on this forum. Canola and quenching oils will do better. If you still have problems send the spring and lock up to me and I will heat treat it.

dave

Thank you Dave. I will try this. I have made a dozen or so of these springs. Mostly out of hack saw blades..ect. for practice just to see how they would turn out. Then I got the steel from Dixie and really took the time to get the dimensions correct. Like everything else I guess when you have not done it before is trial and error. At lest until you reach that AHA! Moment. Thanks for the tips Dave and thanks to others for their Advice. SM

 

[LRB]

Definitely canola oil heated to around 125°/130° which puts the viscosity in an optimum range. Canola oil is the fastest cooling oil without going to a commercial quench oil. Non-magnetic plus one to two shades of red hotter. Non-magnetic is 1414°F. With 1075 you need a heat between 1475° and 1500°. Common table salt melts at 1474°F if you have a way to use that as a guide. Temper at 725° to 750° with a 15/20 minute soak if you have a lead pot. Best to do the temper twice. If going by a color temper, polish first, then heat a bit past when the colors are gone, and it has turned gray.

 

[Billy Boy]

Made many springs for the main spring in my Liege pistol. Used Dixie 1075. Did the usual shaping and forming. Heated red hot...oil quench....failure too soft. Tried red hot ...into cherry red....reheated to cherry red quenched in oil. Failure. No matter what I have tried it has failed. Mind you I spent hours duplicating the factory spring down to the very same dimension. they all came out too soft to give the proper snap of a spring...even the dixie steel. Where am I going wrong? Am I missing a step or process? I know some of you make springs without a hitch. Input is appreciated. If you could give insight PM me.

After quenching ( you must agitate the part during the quench), you must draw the temper at about 700-725 degrees

 

[LME]

Made many springs for the main spring in my Liege pistol. Used Dixie 1075. Did the usual shaping and forming. Heated red hot...oil quench....failure too soft. Tried red hot ...into cherry red....reheated to cherry red quenched in oil. Failure. No matter what I have tried it has failed. Mind you I spent hours duplicating the factory spring down to the very same dimension. they all came out too soft to give the proper snap of a spring...even the dixie steel. Where am I going wrong? Am I missing a step or process? I know some of you make springs without a hitch. Input is appreciated. If you could give insight PM me.

how much carbon is in the metal you are using?

 

[rich pierce]

1075 is 75 points of carbon. 0.75% carbon.

I make a “sacrificial” test piece when working with new steel. Forge or cut a piece the size of a nail. Test hardening it in various heats and quenches till a file skates on it. Then clamp it in a vise with an inch sticking up and hit that sideways with a hammer. It should shear off and go flying. Inspect the grain of the break. Then use what I learned.

 

[ZUG]

1075 is a good spring steel also 1084. I use both and my hardening is done in a stack of fire bricks to form a crude simple oven with a hardware store propane torch for small parts. For larger parts I use either an oxy-acetylene torch & fire bricks or my gas forge. For the tempering I found that a lead bath works best for me. The warm canola oil is my go-to quench oil but I have also used ATF floated on water.

 

[sussexmuzllodr]

Many thanks to all whom responded to my learning curve dilemma. Its appreciated.

 

[J. Paul]

I had good luck, (best results) tempering gun springs in molten lead

 

[mckutzy]

How does this lead tempering work?

 

[J. Paul]

How does this lead tempering work?

Harden as usual, then use the molten lead to temper (same settings I cast round ball) then air cool. I have talked to a few that water cool after minutes in the lead. It needs to be long enough for temperature to be equal through out. I hang it on a piece of wire

 

[sussexmuzllodr]

Through melded advise from Folks on here I used a dog food can with a square window cut near the base. When the oil is hot enough to ignite it stays lit and creates a vortice in the Flames until the oil is burned off. I could have not asked for better results in a finished spring.

 

[LRB]

Lead melts at around 625°. For a good spring from the 10xx steels that will last longest and perform best you need a 725°/ 750°, temper via a lead thermometer. Yes, 625° lead bath will give "A" spring, but it may not, and likely will not, have the longevity or reliability against failure that a higher temper heat offers. That said, much depends on how far of travel is required when flexed, how often the spring will be flexed, and how important is the dependence on it.

 

[Kevin Houlihan]

The timing on this subject was perfect. I needed to make a new frizzen spring for a Becky lock as none are available. No forge so I bought some1075 .250" thick and ground and filed it to shape. After bending the "V" the wrong direction twice I finally bent it the right way. Heated the spring until non-magnetic and quenched in room temp. canola oil. Couldn't file it so I figured the hardness was right. Tempered the spring by sitting the spring on molten lead at about 725 - 750 degrees for 25 or so minutes. Removed the spring from the lead and let it air cool. Scraped off the lead, exercized it a little with a pair of pliers, mounted it in the lock and it worked the first time. I just have some cosmetic filing to do and it'll be finished. Thanks for a well timed discussion!
Kevin

 

[J. Paul]

Lead melts at around 625°. For a good spring from the 10xx steels that will last longest and perform best you need a 725°/ 750°, temper via a lead thermometer. Yes, 625° lead bath will give "A" spring, but it may not, and likely will not, have the longevity or reliability against failure that a higher temper heat offers. That said, much depends on how far of travel is required when flexed, how often the spring will be flexed, and how important is the dependence on it.

My thermometer broke but setting I use, on lead pot, was when new in 700° range. My material was trial and error salvage flat banding from my metal pile so unknown material that worked, and is still working after 10 years

 

[LRB]

Years ago, likely even now, that banding was reported to be 1095 steel. So that would work pretty well for most general use.

 

[LRB]

The timing on this subject was perfect. I needed to make a new frizzen spring for a Becky lock as none are available. No forge so I bought some1075 .250" thick and ground and filed it to shape. After bending the "V" the wrong direction twice I finally bent it the right way. Heated the spring until non-magnetic and quenched in room temp. canola oil. Couldn't file it so I figured the hardness was right. Tempered the spring by sitting the spring on molten lead at about 725 - 750 degrees for 25 or so minutes. Removed the spring from the lead and let it air cool. Scraped off the lead, exercized it a little with a pair of pliers, mounted it in the lock and it worked the first time. I just have some cosmetic filing to do and it'll be finished. Thanks for a well timed discussion!
KevinView attachment 131857

Sounds good, but you need to go about one shade of red hotter than non-magnetic. Also, if you will thermocycle your spring you will get a stronger grain structure. Heat to low orange. Quench or air cool to ambient. Then heat to red orange, air cool to ambient. Heat to a low red, air cool to ambient. Now you will have a fine small tight stronger grain structure. Heat to red orange quench, temper twice.