Billet size for hammer size?

[Derek Melton]

I stumbled across a post the other day about the appropriate size billet and length/diameter billet to use to come up with a particular size rounding hammer, I believe there was a formula does anyone know where this is?

[rockstar.esq]

Derek,

It's tough to answer your question since the size of the hammer you want isn't defined.  Steel weighs 490 pounds per cubic foot.  Since a cubic foot is 12" x 12" x 12", we know that equals 1,728 cubic inches.  If we divide 490lbs by 1,728 cubic inches, we get approximately 0.28 lbs per cubic inch. 

If you wanted to make a 2lb hammer, you'd divide that by .28lbs to get 7.05 cubic inches.

That defines the total volume of steel you'd need to make a 2lb hammer.

If you stayed with square stock you'd multiply the two sides and divide  7.05 by their product to get your necessary length for a 2lb billet.

1" square stock would have to be 7.05" long

1.25" square stock would have to be 4.67" long

1.5" square stock would have to be 3.26" long

If you switched to round stock you'd divide the diameter by 2 to get the radius.  Multiply the radius by itself and 3.1415 to get the area.  Divide 7.05 by the product and you'll get the necessary length for that same 2lb hammer billet.

1" round stock would have to be 8.97" long

1.25 round stock would have to be 5.74" long

1.5" round stock would have to be 3.98" long

If it were me trying to make a rounding hammer, I'd probably go for a larger diameter or larger square section since rounding hammers tend to be stubby.

 

 

 

[Derek Melton]

Thanks, 

I'm wanting a 4lb(ish) rounding hammer and I think I'd need 2 inch diameter by 4.5 inches long....

[matto]

Goggle bostoncenterless.com has a weight calculator, and yes 2" of steel at 4.5" in length will yield 4.000063

[NickOHH]

4 hours ago, Derek Melton said:

Thanks, 

I'm wanting a 4lb(ish) rounding hammer and I think I'd need 2 inch diameter by 4.5 inches long....

You will lose a bit to the plug from punching, scale(small but there) and grinding so it could possibly end up a bit lighter, depends on exactly how much of each are in the process. 

[Derek Melton]

http://www.iforgeiron.com/topic/31181-brazeal-style-hammer-round-stock-questions/

Thanks  

That was the thread. I just made a 1.75 rounder this week in Lyle Wynn's tool making class. For my first hammer I'm wanting to make a larger one. I'm going to start with 4.5 inches of 2 inch thick 4150 hydraulic shaft. I've got a 13yr old son that is going to strike for me. I've been having him practice on driving a rail spike into an old stump. So far he's hitting way more than he's missing.

[Frosty]

You missed the part about losing steel to punching, grinding and scale? Start with 4.75" or a bit more. If it's too heavy a little more grinding will tune the weight for you. You can always take weight off, putting it back is harder, not impossible or very hard it's just a PITA and takes the equipment.

forget the rambl, just star with a little more stock than you think you'll need, it WILL lose weight in the making.

Frosty The Lucky.