C.S. Osborne Metric Arch Punch Set. Osborne Arch Punches are forged in one piece from the finest special carbon steel. A unique feature of the Osborne Arch Punch is the inside taper which permits the punchings to clear easily through the barrel. Punches have fully polished barrel. The cutting edge is fully hardened all the way through and properly finished to provide long use trouble free punching. There is no other hollow punch that can compare. This set of seven arch punches includes the sizes most widely used. Contains 1 each of sizes : 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm They are put up in a sturdy, easy to use canvas tool roll as shown. C.S. Osborne & Co. is a manufacturer of specialized hand tools designed exclusively for upholsterers, auto trimmers, awning and canvas workers, furniture makers and other professionals in related trades. For generations, the family run business has always taken great pride in engineering the highest quality tools and offering our products both here in the United States and abroad. C.S. Osborne produces the most extensive line of custom tools available -and we guarantee that our tools will deliver excellent quality and superior performance.