Can anyone school me in steel hardening?

[Longhorn6120]

As part of my MIG learning curve I'd like to build a kindling splitter. I have a rudimentary plan in my head (I found a guy on YT who made one from an axe head and thought I'd modify it to suit) and have ordered a small quantity of tool grade steel for the blade. It was described as W1.2510 - 01 Tool Steel (100MnCrW1) which I hope will be OK. It's not going to do any serious work, just small log splitting to make kindling.

I'm going to need to toughen it at some point. I remember doing it at school over 40 years ago, but have not done anything like that since. I know I'm going to need to get it hot then quickly quench it to harden it, then heat it again and let it slowly cool to temper it, but could do with some numbers to put around that.

1. How hot do I need to get it to harden it? Is it just a case of getting it non-magnetic and then plunging in water or do I need to get it to a specific temperature?
2. How hot does it need to get to temper it and how long do I leave it at that heat before letting it cool?

Many thanks in advance.

 

[Screwdriver]

Non magnetic is a good rule of thumb but O1 tool steel is oil hardening. I use an ammo box filled with regular vegetable oil. Just mind out for the flames!

Tempering is much easier because you can judge by the colour of the oxide. Straw is a low temper all the way up to blue for a relatively soft, spring temper.

All you need to be aware of with an axe is there's a lot of mass in the body so heat that and allow the temper colours to migrate to the blade. It too easy to heat the surface only so that it looks like a good temper (on the surface) but you want it to be a "through temper". You can also use residual heat to draw the temper back by only chilling the blade, polish it shiny then wait for the residual heat from the main body to migrate, then dunk it fully into the oil.

Failing that, leave it in the oven at circa 260C for an hour or so depending on weight/thickness. You will still see the temper colours. Received wisdom tells me you should temper a blade as soon as you can, immediately after hardening.

 

[TechnicAl]

O1 Tool Steel - Oil-Hardening Cold-Work Steel (UNS T31501)

Cold-work tool steels are high carbon steels that are further classified into three subgroups such as oil-hardening steels, high-carbon, high-chromium steels, and air-hardening steels.

www.azom.com

 

[ronan]

O1 silver steel is great stuff and easy to harden and temper. I make a lot of little punches and chisels from it and if i can harden and heat treat it anyone can. Like Screwdriver i use veggie oil as it doesn't stink the place out like motor oil can. Don't use water as it causes cracks. If making springs, i harden the part and then temper it in a little lead bath, works really well and i have not have one break yet. When hardening, don't quench as soon as the part gets red, hold it at that temp for a few minutes to allow the heat to penetrate.

 

[Longhorn6120]

That's all very helpful, thanks guys.

It's not an axe head I'm making, I just cribbed the idea from someone else who did use an axe head. What I'm envisaging is to make 2 inverted T shapes using 6mm mild steel bar, then joining them together at the top with the tool steel, sharpened edge uppermost. I can then screw the whole assembly to a tree stump and split the logs by holding them on the sharp edge and whacking them with a mallet. A bit like this:

So the size of the tool steel blade will be 4mm x 40mm (ish) x about 150-180mm long.

Also, is it best to have the oil as cold as possible in order to speed up the quenching process? It's thick snow here at the moment (like most everywhere I guess), would it be best to use oil that's been out in the cold or should I get it up to room temperature first?

 

[TechnicAl]

That's all very helpful, thanks guys.

It's not an axe head I'm making, I just cribbed the idea from someone else who did use an axe head. What I'm envisaging is to make 2 inverted T shapes using 6mm mild steel bar, then joining them together at the top with the tool steel, sharpened edge uppermost. I can then screw the whole assembly to a tree stump and split the logs by holding them on the sharp edge and whacking them with a mallet.

So the size of the tool steel blade will be 4mm x 40mm (ish) x about 150-180mm long.

Also, is it best to have the oil as cold as possible in order to speed up the quenching process? It's thick snow here at the moment (like most everywhere I guess), would it be best to use oil that's been out in the cold or should I get it up to room temperature first?

Have you tried one of those Grenade things

I havent....I keep meaning to buy one when im in Toolstation

 

[Longhorn6120]

Yeah, splitting grenades, axes, etc. There're OK, but I find a hydraulic log splitter gets the big stuff done and I just want a small something I can split kindling with. Plus, it'll be a fun build

 

[ronan]

Try to buy Saxon brand O1 if you can, its always good, never had a problem with it.

 

[Screwdriver]

Also, is it best to have the oil as cold as possible in order to speed up the quenching process? It's thick snow here at the moment (like most everywhere I guess), would it be best to use oil that's been out in the cold or should I get it up to room temperature first?

Ideally you would warm up the oil, blacksmiths will dump a heated lump of iron into the quench bucket. If the oil is too cold it can be so viscous it doesn't effectively conduct the heat away from the part, plus there's some weirdness with a vapour barrier forming. The whole process is fantastically complicated (and thererfore incredibly interesting) so rather than try and second guess the why's and wherefores, I just follow the commonly accepted view (among knifemakers) that warm or even hot oil is "better".

Incidentally, for obvious reasons, do not be tempted to use a plastic bucket! This is one of those situations where "what's the worst that could happen" is a reminder you could be standing in a puddle of oil and molten plastic, on fire while holding a red hot sharpened steel blade.

 

[8ob]

As part of my MIG learning curve I'd like to build a kindling splitter. I have a rudimentary plan in my head (I found a guy on YT who made one from an axe head and thought I'd modify it to suit) and have ordered a small quantity of tool grade steel for the blade. It was described as W1.2510 - 01 Tool Steel (100MnCrW1) which I hope will be OK. It's not going to do any serious work, just small log splitting to make kindling.

I'm going to need to toughen it at some point. I remember doing it at school over 40 years ago, but have not done anything like that since. I know I'm going to need to get it hot then quickly quench it to harden it, then heat it again and let it slowly cool to temper it, but could do with some numbers to put around that.

1. How hot do I need to get it to harden it? Is it just a case of getting it non-magnetic and then plunging in water or do I need to get it to a specific temperature?
2. How hot does it need to get to temper it and how long do I leave it at that heat before letting it cool?

Many thanks in advance.

Take a look at bevel edged weldable Hardox or Proforge , https://www.ebay.co.uk/itm/15421364...MI6NmL3_Df7gIV0WDmCh3VdQY2EAYYBSABEgLMk_D_BwE

 

[Longhorn6120]

If the oil is too cold it can be so viscous it doesn't effectively conduct the heat away from the part, plus there's some weirdness with a vapour barrier forming.

That's useful to know, thanks.

Incidentally, for obvious reasons, do not be tempted to use a plastic bucket! This is one of those situations where "what's the worst that could happen" is a reminder you could be standing in a puddle of oil and molten plastic, on fire while holding a red hot sharpened steel blade.

Well, I like to think I'm pretty switched on when it comes to safety, but I'm not sure this would have occurred to me, so thanks again.

So glad I asked here before embarking on it blind.

 

[outofthefire]

If it's really good steel I wouldn't worry too much, we don't harden our coopers adzes and they're only a medium carbon steel, I'm guessing you're going to have a fair wedge of steel just pushing into wood, the wood will give first.

 

[123hotchef]

Yeah, splitting grenades, axes, etc. There're OK, but I find a hydraulic log splitter gets the big stuff done and I just want a small something I can split kindling with. Plus, it'll be a fun build

dont forget the pics

 

[pedrobedro]

You can make a splitter blade out of mild steel or old leaf spring and it will do the job for years with no need for any heat treatment or risk to life and limb from boiling oil.

 

[northwest]

The guy made a meal of that video.
I wonder why, for literally thousands of years we have even bothered making any axes at all?

I wonder if it has ever occured to any of these youtubers that perhaps, rather than re-inventing the wheel it might be a good idea to learn how to use the wheel properly, or in this case an Axe?

 

[angellonewolf]

You can make a splitter blade out of mild steel or old leaf spring and it will do the job for years with no need for any heat treatment or risk to life and limb from boiling oil.

now wheres the fun in that i thought on the fourm we all do jobs and projects just for the fun of it

 

[gaz1]

i dont like it and id rather use an axe however as we get older id like something different so

 

[angellonewolf]

The guy made a meal of that video.
I wonder why, for literally thousands of years we have even bothered making any axes at all?

I wonder if it has ever occured to any of these youtubers that perhaps, rather than re-inventing the wheel it might be a good idea to learn how to use the wheel properly, or in this case an Axe?

was taught by my dad years ago if your confident hold the wood (your choping)lower down so your hand is not near the top a lot less chance of hitting your hand

if your not confident again hold the log lower down gently drop the axe in to the wood so it sticks on the axe remove your hand then tap it on another log to split in to kindling doing this only works for kindling as a heavy log would drop off as your swinging

i hope i explained this well enought

 

[Screwdriver]

I wouldn't have my hand anywhere near a swinging axe (or a gently dropping one). If I have to hold it, I use a piece of kindling. Putting your hand lower down means closer to the chopping surface. I wouldn't say that was any safer!

I am once again reminded of my favourite aphorism: what's the worst that could happen....

 

[angellonewolf]

I wouldn't have my hand anywhere near a swinging axe (or a gently dropping one). If I have to hold it, I use a piece of kindling. Putting your hand lower down means closer to the chopping surface. I wouldn't say that was any safer!

I am once again reminded of my favourite aphorism: what's the worst that could happen....

each to there own ive still got both hands