bar stock size for stock removal, scale loss

So, it seems that 1084 is a decent steel to start working with.. and although this is "the forge" i plan to start with stock removal, at least primarily.

My question is how much metal (thickness) should i expect to loose through heat treatment?

Im thinking of ordering some 1/4" x 1" bar stock, and i'd like to make some wider blades. how wide might that 1/4" be after heat treat and buffing?

Should i really look at getting 1/4" x 1 1/2" if i want to make something wider then 6/8?

i havent looked locally yet to see what steel is available. i had originally been planning on ordering some from Aldo Bruno the New Jersey Steel Baron, although i live in Canada. with Aldo, i /think/ the thickest steel i can get of what i want is 1/4 inch.

anyways, thanks for the help. hopefully i can get off my ass and start grinding some steel this summer.

I don't get the question. You can get a 1" wide razor out of a 1" wide piece of stock, minus a margin that you hone away.
1/4 is thick enough for up to 1".

thanks.. so the amount lost to scale is negligible, i assume..

yeah, i realized after that if i wasn't worried about making it a full 8/8 or larger that 1"x1/4" would likely be fine.. i dont think ill try for anything bigger than 8/8 to start with; beyond 8/8 1/4" thick steel might start to be too thin, so i probably shouldn't bother..
anyways.. sorry for the dumb question.

i was originally going with 1084 because something had made it sound like it was a simpler steel to heat treat. some folks say oil quench, some folks say water or brine can be fine.. i'm hoping for a steel that i can quench in water or brine, as working with heated oil is one more variable and one more piece of equipment to start off with (something to heat the oil to temp).. im going to read up more on some blade forums to figure out the process more.

[edit: anyone know of any companies that will heat treat blades in canada?]

Don't sweat it.
When I harden in oil, the oil is just room temperature. For stainless steels, the HT process is much trickier, but for simple carbon steel it is pretty robust. For O1 just heat to non magentic, and then dunk in maize oil (the cheapest veggie oil I could find). Then temper in the oven. 1095 is water hardening, so I suppose it will work for 1084 as well.

Also the phase diagram for 1084 is the simplest there is, and hardening it should be pretty foolproof.
I don't doubt there are plenty of people in canada who can do this, but if you use something like 1084 or O1, the process is so easy that you should try to do it yourself. Not only will your satisfaction in the end be much higher, but it will also be cheaper and you don't risk losing or damaging your blade in the mail.

Here are some contacts for Ontario:
Onesource Metals - 905-672-1300
Metalsupermarket
http://www.metalsupermarkets.com/

I have some heat treat contacts as well, but most are larger companies. I used to be a purchasing manager for an automotive company.

Quote:

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Originally Posted by ezpz

thanks.. so the amount lost to scale is negligible, i assume..

...sorry for the dumb question.

i was originally going with 1084 because something had made it sound like it was a simpler steel to heat treat. some folks say oil quench, some folks say water or brine can be fine.. i'm hoping for a steel that i can quench in water or brine, as working with heated oil is one more variable and one more piece of equipment to start off with (something to heat the oil to temp)..

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The amount lost to scale depends on two major and persistent variables in forging and heat treating. Those are Time and Temperature. If you leave your steel in the fire above the temperature where scale forms and you leave it there longer (more time) you will have more scale formation. In an ideal heat cycle, you only achieve the minimum temperature to avoid scale formation for the least amount of time. That's the simple part. Without temperature controls and close observation, this equation can wander a lot and produce a lot of different results.

1084 is a simple steel because of its manganese content. You get it hot, quench it and it will harden all the way through the bar. Increasing the manganese content increases the hardenability of the steel. This is a desirable component of the alloy for a shop that wants a fool-proof steel to be heat treated by a minimum wage worker that does not have to think about what they are doing.

I would NOT quench 1084 in water or brine. I do not know why that incorrect information persists but it's a risk every beginner takes because you find good and bad information all over the net. You will shatter far more blades than will survive that violent a quench. It will get plenty hard in room temperature oil, as Bruno has already suggested. If it is not hard enough...then you can try warm water. Definitely not brine. Water quench steels have the least amount of maganese in their formulae. That may be difficult to find out. If you want to quench in water look to W1 or W2 if you can find them.

The only dumb question is the one not asked.

okay, room temperature oil sounds easy enough, and a little flare up is fine, i just don't want a fire, so let the oil cool between quenches or don't quench many pieces in one run. 1084 it is then. ive heard one gallon of quenchant per pound of steel.

someone had recommended placing the piece to be heat treated inside a metal pipe in the coal fire to help the piece heat more evenly. because im working with stoaker coal instead of blacksmithing coal i hope this will cut down on slag. should i have both ends of the pipe open to create a 'reducing atmosphere' (i think thats what it is called when it is low oxygen), or close one end to reduce slag?


ive read that checking for non magnetic only works as you are heating up, because it will remain non magnetic for quite a while as cooling down, far below the point at which one would quench.. so i'll need to check it periodicaly as heating, and then try to hold it at just above that temp for 10 mins once i reach that temp. being a coal forge with a hand crank i dont exactly have great temperature control... would anyone bother with an IR thermometer, or would they just wing it?

maize/canola oil sounds good, because then i can use my home oven to heat treat.. otherwise i'd be buying a toaster oven. not sure how great the thermostat is on either. [edit: i'll probably get a toaster oven so it can be close to my forge and ready to go] i assume i just aim low, and if it isnt tempered enough (the blade chips when honed, or seems tough to hone) i just temper it for another hour at the ?same? or higher temperature.

thanks again.. (im glad i can use room temp oil)

You've already thought through several issues in good fashion.

Once the steel has cooled the fire will go out on the oil surface. Wear a decent glove and you'll be fine.

Heating the steel inside a pipe is a tried and true method for reducing scale formation. I have used a pipe closed on one end, buried in the hot coals. Toss a small piece of coal or charcoal down inside the pipe. As it heats it will consume any oxygen remaining inside the pipe. Oxygen exposure to hot steel is what forms the iron oxides (scale). Keeping the oxygen away from the steel by either a barrier - like flux, or atmosphere control - as in this type of pipe setup will do the trick.

Magnetism is a good simple check for the correct temperature for austenizing the steel. And you are correct about the delay going up in temp and down. Let the material soak for a minute or two after non magnetic. Given enough pieces, trial and error will show you what you want.

Toaster ovens are not the most accurate but if it's the only tool you have, they can be good enough. The swing around the set point can be enough to throw off exact control though. Just one more thing to adapt to until you can afford a perfect tool. Use what you have until you can afford better. Or find a friend with the right tools...

You're on the right track.