Heat treatment gone a foul?????

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kingjoey5000

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Jan 24, 2010
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hey i picked up a piece of scrap steel from a fab shop, shaped it with a file and drill, it came out pretty nice, when i ent to heattreat it i got a layer of hardened scale, that peels and breks off like paint? is this right? I really cant tell if the blade if harder or not, i ran a file across it and it still scratchs it, does not seem to so as much, but i dunno its my first blade.:jerkit:
any ideas here fellas??
 
ok im not sure what kind of steel, it seems annealed, but i dont know the alloy make up as i went to a fab shop and bought a scrap piece, she tryed to give me galvanised, i said no, all i know is they said it was hot rolled steel. I brought the blade up to the non magnetic state and quenched it in sae 30 new motor oil, the first time i tryed it the whoule pan cought on fire and wouldnt go out, blade still took biting from a file so, the second time i added and extra quart and a larger container, so it could handle the heat dispersion a little better. i realise the the steel, may just be crap, luckily i have a piece of 1095 barstock coming in the mail again any suggestions???
 
oh yeah is the coating of scale that formed normal???? And the fab shop makes hinges, and art, and and heavy industrial fab, the piece i got is about 1/8" thick and 1 inch wide, seems like plate that the cut into a small bar
 
I don't think a flaky hard layer of scale that will scratch and peel is normal. My recommendation is to go to a local automotive spring shop. Most will carry 5160 in a hot rolled form. A 1/4"x2"x36" piece will run you roughly $25.00. They may also let you rummage through the scrap bin for free, though the steel from the scrap bin may or may not be 5160. You will need to straighten the piece and they may do it for you for $5.00-$10.00. This should tide you over until the 1095 arrives. One advantage of 5160 is it is pretty easy to heat treat with the equipment you described and it makes a pretty nice blade. 1095 can be tricky in the quench, but you should be able to get it to harden pretty well in oil. A commercial quenchant is better for 1095, but can be a little expensive.
 
kingjoey5000 said:
oh yeah is the coating of scale that formed normal???? And the fab shop makes hinges, and art, and and heavy industrial fab, the piece i got is about 1/8" thick and 1 inch wide, seems like plate that the cut into a small bar
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Your steel is almost got to be regular mild steel. They would have almost no need for the more expensive types of steel that would make a good blade. I ran the floor in a fabrication shop and the only thing we ever got in besides mild steel was some AR plate (armor) and a little mild stainless. By the way hot rolled is a process more than a type of steel. Almost any steel type at one time way hot rolled. Some is then colded rolled. Cold rolling reduces scale, is more accurate, and work hardens the piece. Work hardening is not the same as a heat treat hardening and will go away as soon as you heat the piece.

That said your time was not wasted as you got valuable practice. I would suggest that you do yourself a favor and read some of the stickys on top of the page. There is a ton of valuable info there and it would be time well spent.
 
hey thanks for your replys, i re heat treated and got a very hard tightly adhered layer of scale, i had to chip this stuff off, still not sure if this is nopmal or not but polished the hell out of the blade it looks great and seems to be holding a nice edge, im not going to chunk it, im waiting on my handle material. how do you pos pics in your threads?????:confused:
 
Like the others said, you probably have mild steel which isn't any good for a knife. Stick with it and wait for the 1095 to arrive.

What island? My brother lives on St. Croix. Can't wait until May when I get to go for a couple of weeks.

I think to post pics if you aren't a paying member of the site, you have to use a photo hosting site like snapfish or photobucket.

-Mike
 
Have you tried quenching in just water? You might be surprised at how well that can work sometimes. Just experiment and have fun and maybe you'll figure out something that nobody else knows that will work.

BTW, how are you heating your knife blade?
 
I heated it up on kingsford charcoal, its my first attempt at creation, so give me a break on this, i was able to basically break the scale off the blade by lightly tapping at it with the corner of my file, this stuff was thick, and very hard, but i finally got it off, the blade looks great, im proud og the design, and cant wait to put a handle on it, i have some g-10 coming, i will try the water quench some time. ill try to get a pic up!
 
ok heres a pic
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hopefully it will come out
 
here it is in a rougher state, dont blast me two hard, all i had was a drill, saw zaw, 3 files, and sandpaper
DSC_0128.jpg
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That looks pretty good. Little more work on the plunge cut on the next one and you will have an excellent looking knife. Good luck
 
thanks man, i think im going to go with almost the same pattern for the next i have a book in the mail to on knife making, so maybe i can figure the right way to do a plunge cut
 
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