Question about spring heat treat/tempering

[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

[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

[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.

[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

[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

[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.

[Jeffinn]

Thanks everyone!
Jeff

[Nev52]

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

[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