Hi Mathius!

First of all, Happy Holidays to you, your family and Friends!!!

I looked at the website and scrolled down to the bottom of the page.
It reads: 0.25" strap (flat bar how wide of a limit?), 0.25 round in grooves (I believes he's talking about the grooves on the rolls) and 0.125" sheet "easily" according to the page.
Hope this helps...

Respectfully,

SSBN727 Run Silent... Run Deep!!!

This is a manual slip rolls forming tool. Using it one can form round (radiused) bends of varying radii in sheet metal. One can also roll a piece of sheet metal into a round tube, with an open longitudinal seam. This particular slip rolls tool can handle sheet as wide as 22" X 0.125" in thickness (annealed aluminum, the builder probably means). However, I wouldn't want to be the one turning the crank to roll a piece of 1/8" thick X 22" wide sheet. It would take the arms of a WWF wrestler to form a piece of that thickness by hand!

I have a Harbor Freight slip rolls tool with a width capacity of 45". By coincidence this week I have been helping my son-in-law build a custom aluminum oil tank for a motorcycle that he's building from the ground up. We rolled just a 4" wide X 0.050" thick X 42" long piece of alloy 5052 aluminum to form the roughly oval cylinder that makes up the side walls of the tank. We had to turn the crank with two hands to form the bends. My slip rolls tool can form sheet metal up to 22 ga. thickness in mild steel or about 18 ga. in aluminum. The wider the sheet and the tighter the radius that you're forming, however, the more muscle you have to apply to the handle to turn the rolls. There are powered slip rolls available but I haven't seen one that will handle mild steel thicker than 16 ga. Here is a picture and specifications for an Enco 50" wide, 3/4 HP slip roller:

http://www.use-enco.com/CGI/INPDFF?PMPAGE=128