C.S. Osborne Arch Punch. Diameter : 3/8" Osborne Arch Punches are forged in one piece from the finest special carbon steel in sizes from 1/8" to 2-1/4" diameter. Larger sizes are made with our properly engineered two piece welded construction. 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.Forged, hardened and polished edge. Inside tapered for easy clearance. Made in USA. Many other sizes are available in our shop and additional sizes are also available upon request. 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.