Beginners Heat treating SUP9 / 5160 steel

For my next installment in the beginners series I decided to do the fast and loose approach to heat treating 5160 & SUP9 (which are the same thing).
This method will be suitable for people who ALREADY have an Oxy/LP Oxy/Acetylene rig. This will work for smaller knives with the Bunnings brand Bernzomatic torches. It is far cheaper to buy the parts for a gas forge that will do a much better job of your heat treating than it ywould be to go out and buy a $400 cutting torch set and rent an Oxygen bottle. This is by no means a definitive guide to the heat treating of spring steel for knives... just a place to start.
Heat past non magnetic (Ideally 830 Celcius) and hold for 2-5minutes
Quench blade first into oil (conola, vegetable but not motor oil)
When cooled to room temperature grind surface back to expose bright steel
Test bright steel at edge, if hardened correctly it should be "glassy" a regular file should have a hard time marking it
Put in kitchen oven on 205 Degrees Celcius for 2 hours, then let cool outside of the oven to room temperature. Then repeat. Steel must be tempered twice.
This should result in a blade that has a degree of toughness and hardness suitable for use as a knife.
Steel = SUP9 x 6mm x 70mm x 1200mm
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Tongs: Wayne Saunders Knife makers tongs
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Thermocouple reader : (ignore the photo it is different)
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Thermocouple:
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[@adambeck6228]

good video. thanks Dave. The heat treat you did on my blades was great

[@batcountryforge5945]

Adam Beck your blades were done a little differently to this. More electronically controlled kiln and less fire haha. Thanks mate!

[@marktyler1807]

Great video very helpful Thanks!

[@ja39381]

Thanks for the info man really appreciate it. Good explanation and walk thru thanks again

[@DogsaladSalad]

nice drum throne :p

[@obi-wankenobi9871]

If you do a few normalizing cycles you should be fine without an extended soaking time.

[@AaronJohnson1979]

You look like you were about 16 to 17 hundred degrees on that knife

[@MarioMario-vr9fp]

Very helpful video just i want to understand do you advise us to use this kind of torch which is about oxy and probane gas instead of using forge because it is easier& cheaper &work good waiting your answer Thanks

[@batcountryforge5945]

Mario Mario no, you can build a proper forge with temperature control for less than buying an oxy torch. If you already have a torch though and cant wait to get started they are pretty effective.

[@olivermilutinovic749]

Could you heat treat 5160 in a charcoal forge like 1084, say minimal soak time and let it go just past non magnetic, quench in canola oil afterwards. I have used 1084 with success for blades and tools, but would like to use a tough big chopper type steel for large blades, but backyard heat treat set up.

[@batcountryforge5945]

The soak time would be key to getting the most out of spring steel. You really want to get that cromium and silicon disolved properly to get any of the benefits of using the spring steel. Otherwise stick to your 1084. I mean you could do it and you will harden the steel some but you could get a better result if you get temperature a d time right.

[@olivermilutinovic749]

@@batcountryforge5945 Thanks for the info.

[@ernestobarrameda1087]

Does sup9 holds an edge like 5160?

[@ryanadams7440]

Hey there great video! I have made a big ish knife out of a piece of leaf spring steel, got to the point of quenching and oven time but a friend says not to harden it as it will break.. Do you recommend doing this process to a larger 260mm blade length 52mm wide 5mm thick Handle length 120mm? I'm also worried it will crack along the edge where it's thinner

[@batcountryforge5945]

To put pretty simply, If you don't harden the steel you don't have a knife. The spring would already be heat treated but to the optimal working hardness for it to perform well as a spring. This might be as low as 45HRC, usually most hand knives start from around 55HRC for a tough outdoor knife, kitchen knives can be over 60HRC. Weather it survives heat treat or not will depend how thin you made that edge. I'm obviously having to make a few generalisations here as I can't see your knife but if the edge is thinner than 1.5mm you might be in crack territory, especially f you can't get the temp even along the length of the blade. I heat treat thinner than that for most of my knives but if its your first go give yourself as best chance to succeed as possible. If so grind the edge back until it is a little thicker. If it does crack during the quench you will have learnt more than if it worked out fine. Let me know how it goes.

[@viorelolaru2605]

what hardness (HRC) did you achieved after oven tempering?

[@agylub]

What's a scientific reason for not recommending motor oil? What camera and video editing did you use? Very good quality video ( and Australian for a change yay)

[@zackslaststand]

agylub I don’t think there’s too much of a scientific reason beyond it makes horrible smelling toxic fumes that you definitely don’t want to be breathing

[@justinriley8651]

Yep what he said is right

[@anonymous-mj8wb]

How long in the oven? I dont think i heard but i would appreciate if you could say

[@batcountryforge5945]

Hi, 2 hours on 200 degrees celcius let it cool to room temp and then repeat. You must temper twice to get the proper effect. If you want to increase toughness and reduce hardness you should increase the temp to around 220 and check again. You should choose a hardness for the blade based on its application.

[@stanleyjaxen8759]

is this steel good for making wood chisels?

[@batcountryforge5945]

Sure you could make a chisel from it.

[@igorpadurjan5714]

What are some tips for working with coil spring? I quenched a bit of a sabre thi ng i made and im wondering how do i normalize it, oven too small.

[@batcountryforge5945]

1st tip is work with jobs you have the correct tooling to complete successfully. Or know the limitations of your workshop ;) I think you might mean temper? Your best bet is to grind the steel clean and use a hand torch to heat the steel until you see it change to a straw colour ( or which ever colour corresponds to the hardness you want on a relevant chart.) The real answer is much longer than I can put into a youtube comment unfortunatley.

[@igorpadurjan5714]

@@batcountryforge5945 Yes, i meant temper, ill try that method. Thanks

[@levvy001]

So you're a drummer?

[@syitnoqibro2262]

What is oil name ???

[@grigoriyefimovichrasputin7897]

In the description it reads canola oil

[@ayurvedicherbadityagoyal8242]

Dear sir can you tell me if oil are not available so use water for this process

[@batcountryforge5945]

Do not use water for quenching steels if you are just starting out.

[@ayurvedicherbadityagoyal8242]

Dear sir thankyou for reply so please tellme about oil we can use plane conola or vegetable oil or mix anything in this oil please tell me

[@tswbtshoj1]

Where can I buy a torch like your?

[@batcountryforge5945]

I got mine from Bunnings, also sold at gasweld and total tools in Australia.

[@joolion8178]

i live in thailand and can get sup9 i want to make a knife with my lil brother but i cant find anything on heat treatment temperatures and all that maybe someone canshare some info thank you

[@batcountryforge5945]

If you are buying the steel and not recycling an old spring. Cut the knife out, grind it to 1mm thick at the edge, heat it to 830 degrees celcius and quench into vegetable oil. Then put into an oven on 200 degrees for 2 hours. At the end of 2 hours take it out to cool to room temperature then repeat this step again. After that grind it to the final edge without letting it get to hot so cool it with water. Most importantly, when you have finished test the blade. If it cracks you need to increase the oven temperature 10 degrees and try again. If the edge is too soft maybe it didn't harden or you over heated it while grinding.

[@joolion8178]

@@batcountryforge5945 im so excited to try thank you i will let u know if it worked :D

[@joolion8178]

@@batcountryforge5945 770 is when the magnet doesnt stick any more? just tried it and the blade fell down after quenching and a little bit of tip broke and the file does bite into it a little bit. should i try to harden it again or should i proceed with the oven steps now. thanks

[@joolion8178]

bought as much as i could im just missing a magnet and thermometer that can measure 830 degrees lol

[@joolion8178]

also im doing this in a big can of beer(the quenching) or do i need a big bucket of oil like you have

[@kibbsnowden6893]

This is not how to heat treat a spring steel blade...The point is to make the blade hard and flexible...Put this knife in a vise and hit with hammer and it will break, A properly heated knife will not break...;) It is a lost art...I have watched a lot of videos on heat treating spring steel 5160 on youtube and none have hit the mark...Try the vise and hammer test with just a piece of spring steel that way you dont waste your time making a knife that will break ....

[@anarchistangel2314]

So. How do you properly heat treat spring steel to get that balance of hardness and toughness? I've been making tools out of the stuff but I'm not finding a lot of info on heat treating

[@krissmith007]

@@anarchistangel2314 the video is right. Tempering the blade as per video will prevent it being brittle and give it some toughness / flexibility.