Calculating steel

billyO

Well-Known Member
Volume = Length x Width x Height.

So if your knife is 1" tall, 8" long and 1/8" thick, you will need at least 1 cubic inch of steel to make this final blade (well, actually more because you will lose some material in the forging process). But it would be a lot easier to forge out the blade from an 8" piece of 1" x 0.125" than 1 inch of 1"square stock, (or 4 inches of 2" x 0.125", etc...)

But this also depends on whether you are doing stock removal or forging, if stock removal, you will need to start with a lot more than forging.
 

52 Ford

Well-Known Member
I'd you're copying a knife...


If you want to get fancy, you can drop the knife in a graduated cylinder, fill it up with water, pull the knife out and measure the change.

Or put the knife on a scale and do the math. Mass to volume.


OR draw it in CAD and extrude it to thickness and look at the material properties - namely volume.

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jmforge

Well-Known Member
One of the first knifemaking DVD's that I bought was the Charles Ochs basic forging video where he made a 7 inch fighter from 52100. He took a 7 inch piece of 1/4 thick bar stock and forged the though tang knife from it. Combination fo thinning a little bit and distal taper made it work.
 

52 Ford

Well-Known Member
One of the first knifemaking DVD's that I bought was the Charles Ochs basic forging video where he made a 7 inch fighter from 52100. He took a 7 inch piece of 1/4 thick bar stock and forged the though tang knife from it. Combination fo thinning a little bit and distal taper made it work.
Every knife I've forged, I didn't measure anything. I figure out the lengths I need to forge and write down the rough numbers. As I forge, I'll mark distances on my anvil face with soapstone.

I forge the blade first on the end of the stock, then start to draw out the tang a little, estimate how much metal I need for the tang, and hot cut my stock off there. Then I forge the tang.

I work almost exclusively from round bar stock. 1/2" being the smallest I think I've made a knife from. Usually 3/4" to 1" bar. Just cause it's what I have on hand. I got a bunch of it a while back (and might be getting more, soon).

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tkroenlein

Well-Known Member
I don't forge a whole lot, but enough to have a plan when I do. I forge 1/4" stock mostly. I figure it it terms of finished dimensions, plus material loss. So if I want an 1/8" thick knife, 1" wide and 10" long,
I'd start with 1/4" thick, 3/4" wide, 6" long, and grind off extra thickness or cut off excess length as needed.
 

Mod

Member
Yep, I look at the steel I am forging, and sort of imagine it all squished into the shape of whatever I’m making, and use that much of it. Very scientific.
Now that’s what I’m talkin about! I knew all that math I took would come in handy. I’ll have to go back and read up because I don’t remember studying the swish factor, must of missed that day. Thank you, sir. Heading to the forge to squish some shit out!! Lol
 

Mod

Member
I don't forge a whole lot, but enough to have a plan when I do. I forge 1/4" stock mostly. I figure it it terms of finished dimensions, plus material loss. So if I want an 1/8" thick knife, 1" wide and 10" long,
I'd start with 1/4" thick, 3/4" wide, 6" long, and grind off extra thickness or cut off excess length as needed.
Thanks
 

Mod

Member
Every knife I've forged, I didn't measure anything. I figure out the lengths I need to forge and write down the rough numbers. As I forge, I'll mark distances on my anvil face with soapstone.

I forge the blade first on the end of the stock, then start to draw out the tang a little, estimate how much metal I need for the tang, and hot cut my stock off there. Then I forge the tang.

I work almost exclusively from round bar stock. 1/2" being the smallest I think I've made a knife from. Usually 3/4" to 1" bar. Just cause it's what I have on hand. I got a bunch of it a while back (and might be getting more, soon).

Sent from my Champion Forge using Tapatalk
Thanks
 

Mod

Member
I'd you're copying a knife...


If you want to get fancy, you can drop the knife in a graduated cylinder, fill it up with water, pull the knife out and measure the change.

Or put the knife on a scale and do the math. Mass to volume.


OR draw it in CAD and extrude it to thickness and look at the material properties - namely volume.

Sent from my Champion Forge using Tapatalk
Thanks
 
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