How important is press tonnage?

[Leon Husock]

Is it just a matter of speed of work (e.g. a 24 ton press will do X amount of work in half as much time as a 12-ton press) or are there projects that just aren't going to be possible with a 12-ton press but which become possible on a 24-ton press? I'm looking into buying one but don't have extensive experience between presses at different tonnage levels.

 

[weo]

If you are just going to be forging knives and other things using smaller stock, then all the above should work.
If you plan on doing projects that involve larger stock (ie hammers, sculptures, etc) then tonnage is important and more is better.
I only have experience using the Coal Ironworks 25 ton (currently) and a few years ago had access to a shop with a 100 ton press, so can't speak to how well the smaller presses work or what size stock it will handle effectively, but I'd say that you'd have a hard time making hammers with a 12-ton, but I could be wrong.

 

[Leon Husock]

If you are just going to be forging knives and other things using smaller stock, then all the above should work.
If you plan on doing projects that involve larger stock (ie hammers, sculptures, etc) then tonnage is important and more is better.
I only have experience using the Coal Ironworks 25 ton (currently) and a few years ago had access to a shop with a 100 ton press, so can't speak to how well the smaller presses work or what size stock it will handle effectively, but I'd say that you'd have a hard time making hammers with a 12-ton, but I could be wrong.

I'm mostly doing Damascus billets, but people seem to manage to do hammers on the 12-tons alright. But yeah my main goal is to have something to take big ol' chunks of Damascus/canister welds and squish them down into flat bars.

 

[kdnolin]

I have a gauge on my 50 ton and when drawing out a billet I take it to 10-15 tons. It seems to get too cold if I take it any further. Setting initial welds I take it to 30, might be overkill, but I have had good success as a beginner with both san mai and damascus.

 

[weo]

my main goal is to have something to take big ol' chunks of Damascus/canister welds and squish them down into flat bars.

With properly shaped dies, I'd think a 12 ton would handle this.

Perhaps the question should be: what's your definition of "big ol' chunks"? But again, with properly shaped dies, it should be doable.

Don't forget the old adage, "Buy once. Cry once". So if you're on the fence, I'd suggest buying as big as you can afford. As you get used to the smaller one, you'll probably wish you had gotten more power. (I'll admit, I'm still thinking more like a blacksmith than bladesmith here)

 

[Leon Husock]

I mean don't get me wrong, I'd also like to do sculpture at some point in the future. But I think I'd prefer a power hammer for that, just because I find it harder to get smooth, continuous shapes in a press unless the continuous shape you're going for is flat/square. But that could just be my lack of experience.

 

[weo]

I find it harder to get smooth, continuous shapes in a press ... But that could just be my lack of experience.

Me too, but that could be just my lack of experience as well.

Seeing as how you brought up the power hammer comparison, one thing to think about when deciding between the two is how they differ in moving the metal. It's my understanding that a press will tend to move the center of the billet more than a hammer, which tends to move material closer to the periphery.
I'll ask those who know more to correct me on this, please.