Seamless Feed-Thru Punches are used to cut leather products, gaskets, rubber, foam and similar materials. These are machined with additional clearance behind the cutting edge to facilitate the ejection of cut disks through the back of the punch. These are also called as clicker punches.
Seamless pipe is made from a solid billet of steel, which is pierced to form a hollow round section and then drawn through dies to finished dimensions. It is inherently strong as it has no welds. It is used often in the petrochemical industries.