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Question about spring heat treat/tempering
Posted: Fri Jul 08, 2022 12:45 am
by Jeffinn
When you make a new spring (from carbon steel like 1095) I know it needs to be heat treated. I’m assuming it needs to go through a tempering cycle or two as well similar to knife blades. For those of you who make their own springs, after heat treating do you temper them similar to a knife blade (two cycles at 400 degrees for two hours then let cool slowly in the oven). Or is there a different approach for spring tempering?
Thanks.
Jeff
Re: Question about spring heat treat/tempering
Posted: Fri Jul 08, 2022 4:05 am
by ea42
Jeff that's to low, I think you need to be looking at around 665-700 degrees for about 30 minutes. One cycle should do it.
You can also melt some lead which has a melting point of about 625ish and submerge the spring until the lead stops sticking to it. That's the way they used to do it in the old factories. It's a slightly lower temp but still works well with minimal equipment.
Eric
Re: Question about spring heat treat/tempering
Posted: Fri Jul 08, 2022 4:24 am
by Kramersknife
I tried heating till it was non magnetic quenching in oil then heating it on a brass plate w/ torch till the spring turned a dark brown color and that worked out well for me.
Re: Question about spring heat treat/tempering
Posted: Fri Jul 08, 2022 2:02 pm
by just bob
Kind of a common notion to heat to cherry red, quench in oil, bake in 350-degree oven for an hour. That is in one of Goddard's books - I'm pretty sure -or maybe something very similar.
Here's a video.
https://www.youtube.com/watch?v=0RoozxYUi74
Re: Question about spring heat treat/tempering
Posted: Fri Jul 08, 2022 3:44 pm
by Mumbleypeg
Springs need to be hardened to apprimately the same hardness as the blade tang, or visa versa, to prevent the two from "wearing" on each other.
Ken
Re: Question about spring heat treat/tempering
Posted: Fri Jul 08, 2022 5:51 pm
by wiseguy
I have had great results by simply heat with a torch to non magnetic and red hot to a canola oil quench , then torch to just past purple to cobalt blue ( aprox 600 degrees)and stop.
Re: Question about spring heat treat/tempering
Posted: Sat Jul 09, 2022 12:20 pm
by Jeffinn
Thanks everyone!
Jeff
Re: Question about spring heat treat/tempering
Posted: Sat Jul 09, 2022 1:46 pm
by Nev52
Jeffinn wrote: ↑Fri Jul 08, 2022 12:45 am
When you make a new spring (from carbon steel like 1095) I know it needs to be heat treated. I’m assuming it needs to go through a tempering cycle or two as well similar to knife blades. For those of you who make their own springs, after heat treating do you temper them similar to a knife blade (two cycles at 400 degrees for two hours then let cool slowly in the oven). Or is there a different approach for spring tempering?
Thanks.
Jeff
Jeff,
I talked to a blacksmith a couple weeks ago. I explaned I had tried different ways to temper steel with poor results. So I used lawn mower blades. He explained to take a small can like a sucrets tin put the made spring in the tin fill it with motor oil and light it on fire.When the oil is burned off the steel will be tempered. I have not tried it yet. Just wanted to give out this information.
Nev
Re: Question about spring heat treat/tempering
Posted: Sat Jul 09, 2022 3:54 pm
by Jeffinn
Thanks Nev, I saw that technique posted in another forum.
Not sure if I want to start a small oil fire to temper a spring but it’s worth considering!
Jeff