Avoiding fish-mouth on Damascus billets?

L

Leon Husock

Joined
Jul 17, 2019
Messages
323
I only have a 12 ton press and I find that when I make tall billets (say, 2.5 or maybe 3+ inches) inevitably the tops and bottoms of the ends push out in a fishmouth and then when the whole thing is forged down to restacking thickness that fishmouth closes up and I have to cut an inch or so off each end. I understand the reason this happens is because my little press isn't strong enough to move the whole billet evenly at once, so the tops and bottoms get more force and smush out. My question is, is there any way to avoid this with the equipment I have? I've tried upsetting the ends and it inevitably causes delaminations.
 
A bigger press would fix the problem.

Otherwise, make shorter, longer, narrower billets and restack one extra time.

Hoss
 
Also, make sure the billet is fully heated ALL THE WAY THROUGH. It takes longer for the center of a big billet to reach the temp of the outside. If the center is cooler, the top and bottom will stretch out in the fish mouth. Give a big billet an extra 5 minutes and see if that helps.
 
Last edited:
Also keep in mind if your 12 ton press is an Coal Iron "12" ton and has the 3" cylinder they come with, it's only a 9 ton. AND if your press is like the one I got from them the pressure was set at only around 2100 psi giving well less than 8 ton. I changed to a 4" cylinder and easy get the 12 ton now - yep, it does make a difference.
 
You could also just take smaller bites and square up the end by hand each heat. Correct the fish-mouth before it gets un-fixable.
 
You could pinch the bejeezus out of the billet, just behind the fish mouth with some round dies. That would pinch off the little bit that's become the fish mouth, and drag the lines of the Damascus pattern to follow the tip of the blade.
'course if you're not careful you might incorporate the fish mouth into your pinch.
 
You must log in or register to reply here.
Back
Top