DIY heat treating

[greenreese]

Recently I have been making a nice big knife out of a piece of steel I found in my garage that came from the mechanism that opens and closes the garage door. Is there any way to heat treat the steel at home? From what I gather I have to heat it until it is orange and non magnetic, quench it in oil, and then temper it in the oven at 4-500 degrees. Is this worth it, or should I leave it how it is?

Thanks!

 

[hardheart]

it probably won't harden

 

[Kiah]

Like hardheart said. It's probably not gonna be usable as a knife.

 

[greenreese]

Why's that?

 

[Kiah]

Why's that?

Unless you know what the steel type is, it's gonna be hard to tell you whether it would work or not. That said, if it came off of a garage door, it's probably not gonna hold an edge. You can buy barstock of knife steels that you can pretty much HT as you described.

Edit: Well not exactly as you described, but the concept is the same.

 

[hardheart]

if it's mild steel, it will have little carbon, which you need to get it to harden

now, the steel for the spring on the garage door mechanism, you could maybe forge that into something

 

[Kiah]

A suggestion.

In the upper right hand side of your post, you'll see a triangle with an exclamation point in it. Click on it, and request that this post get moved to "Shop Talk". You'll get more answers there.

 

[Cougar Allen]

Welcome to Bladeforums!

Let’s see if we can find the right forum …

 

[Sam Salvati]

IMHO what Kiahs and double H said is true, most likely not good steel, you are better off buying factory good steel.

Welcome too by the way!

 

[bjalongi]

Yes, it's probably crappy steel. But, heck if you've already worked to a point where you think you need to harden it, you probably learned a good amount.

You could try to harden it for the heck of it. Might be a waste of time, though.

I would take any skills you've learned from the garage door part, and quickly use it on a good piece of steel.

 

[greenreese]

It's about 18in long, 1/4in thick and hollow ground. With a mahogany handle I hand filed from an old piece of our deck. I made it just for fun, because I love to make things. But yes, it is pretty soft mild steel. I do have the old spring sitting in the basement waiting to be used on some other yet to be thought up project.

 

[Dan Seaver]

Well if its mild steel you could try the "super quench". Your better off with known steel than the spring, its not that expensive if you buy it from the right places.

" The Formula
5 gals water
5lbs table salt
32 oz dawn dishwashing
liquid (blue)
8oz Shaklee Basic
(A Wetting Agent)

Quench at 1550
Light cherry red)

Expect 43 to 45 Rockwell
C on 1018
steel and low carbon
steels"

You should fill out your profile, there might be a maker in your area who could help you.

-Dan

 

[scottickes]

Another suggestion is to read through all the stuff in the "newbies-good info here" stickie at the top of the shoptalk list of threads. After reading through all of that, you'll have answers to all of the questions in this thread, and answers to many more questions that you will have in the future. It will be time very well spent! Great information in that thread. The purpose of the thread was to compile all of the best advice and facts about knifemaking into one easy to access place.

 

[Jeff Clark]

The grade of steel used in buildings is usually a "structural steel". This has only about .2% carbon in it. It is designed to be soft enough to stretch plastically to even out pressures and to resist cracking. Even if you heat it up and quench it very fast it doesn't get as hard as cutlery steel. Dan Seaver's directions tell how to quench steel extremely fast so that you get the maximum hardness possible out of a low carbon steel. If you quenched a high carbon steel that fast it would probably break.

High carbon steel usually has over .6% carbon in the mix. If you quench it fast and don't temper it you get a quenched hardness above 60. If has enough carbon it will get so brittle after the quench that it would shatter if you dropped it onto a concrete floor. You need to bake it for an hour or so around 450 degrees to get the hardness down a little below 60 to be both hard and yet tough.

Anyway you need to start out with a steel that is intended for making springs, tools, or knives if you want to get into the 55 to 62 RC hardness range that most people want in their knife blades. You can salvage a car leaf spring or a planer cutting blade and expect it to be a practical alloy for a knife. A random chunk of bar stock or building bracket is going to be too soft.