Tool steel

[marcros]

I have a little tool that I want to make which requires a piece of steel approx 100x40x5mm. One option is to go and buy a bit of o1. Obviously I would need to harden it but it is possible at home I think.

Another is to take an old chisel- old as in no historical significance etc or an old planer blade. If I was to do this, would I have any hope at all of drilling it in its hardened state?

 

[porker]

Hi, Not with an ordinary HSS drill that's for sure. You might with a carbide drill. I don't know what you want to make but could you grind it, maybe with a dremel type tool?

 

[RogerP]

A Stellite drill bit should do it.

 

[marcros]

Hmmm. They sound far from cheap. Interesting bits though by the sound of them.

 

[Phil Pascoe]

Anneal it and harden after drilling?

 

[Spindle]

Hi

The easiest way would be to buy gauge plate and harden / temper after production if you have the capability - it's accurately ground so should save you some work as you can buy exactly the size you specify.

http://www.m-machine-metals.co.uk/metals_gp_flats.html

Regards Mick

 

[marcros]

Thank you for that. How do you harden gauge plate- I have never really known what it is. I understand the o1, a2, d1 etc grading system.

 

[rxh]

Gauge plate is 01 steel, delivered in the annealed state so you can saw and drill it. It is hardened by heating to red heat then plunging into oil and stirred about to get even cooling. I believe any oil will do - you need to do this outside as there will be smoke and a filthy smell, and it might go on fire too. Old engine oil would work but I think some people use cheap cooking oil as the effects are less offensive. Obviously you should wear suitable PPE. Then you need to temper it to the required hardness. This can be done in a domestic oven if you trust the thermostat or have a suitable thermometer and SWMBO permits (or does not find out :wink: ). The steel usually comes in a paper wrapper with cooking instructions - see photo below. I have not tried this but I plan to have a go at plane blade making soon.

 

[Harbo]

I use a blowtorch and heat to cherry red. Anneal as rxh said - doesn't damage the cooker.
Do all the shaping, drilling etc before hardening!

Rod

 

[marcros]

How much shaping would you do before hardening on a plane blade. Primary bevel or only part way there in the primary?

 

[Hemsby]

+ 1 For gauge plate.

If you have never done any hardening & tempering be very careful.

Normally the correct oil has a high flash point, using any other type of oil can result in unexpected ignition of the oil with serious consequences. If you use anything other than the correct oil, and even then make sure you hold the material in some long type of tongs and keep your GLOVED hands and face well away.

 

[Harbo]

I was thinking of the outline - leave bevel for grinding afterwards in case of heat distortion?

 

[marcros]

to be honest the hardening is well down the line- i would probably find a local blacksmith or send it somewhere. annealing doesnt concern me so much.

 

[marcros]

I was thinking of the outline - leave bevel for grinding afterwards in case of heat distortion?

ah ok. makes sense.

 

[Hemsby]

to be honest the hardening is well down the line- i would probably find a local blacksmith or send it somewhere. annealing doesnt concern me so much.

Probably the best route

 

[Andy RV]

Don't let the hardening put you off, have a look on http://www.britishblades.com/forums/content.php for lots of hardening and general metal working advice.

In the past I made a furnace using a small (5kg?) gas bottle cut in half with holes drilled into the bottom to let the air through, this sits on top of an empty steel paint tin with a pipe from your air source, mine was an old HVLP unit, for fuel I used bbq charcoal, when it's up to temperature you'll find that the steel will become non-magnetic, I quenched in cooking oil then into the oven at 200 for tempering. (hammer)