The Machine That Made a Hole Through Solid Steel Without Drilling It

In 1885, a German patent was filed for a machine two brothers had built in Remscheid: it tore a hole through solid steel without a drill, a saw, or any cutting tool ever touching it. This is the story of rotary piercing and the pilger mill, the Mannesmann process that produced the first true seamless tube and ended the one weak point every riveted and welded pipe had always shared: the seam. You'll see how a bench test with rolls set at an angle opened a cavity dead center in a spinning steel billet, why a mandrel had to be added to keep that bore running true, and how hot rolling and cross-roll piercing turned a workshop accident into a process still used for boiler tube and high pressure pipe today. From bicycle frames in the 1890s to the oil drill pipe and power station lines running right now, the same two machines, in the same order, are still opening that hole the same way. CHAPTERS 0:00 Intro 2:03 The Problem With Seams 2:50 File Makers From Remscheid 4:08 A Hole Forms Itself 6:11 Scaling Up The Mill 7:32 Mandrel And Steel Problems 9:54 The Pilger Mill 12:30 Seamless Tube Changes Everything SOURCES S. F. Jeter — Riveted Boiler Joints: A Treatise on the Design and Failures of Riveted Boiler Joints (McGraw-Hill, 1917): https://archive.org/details/rivetedbo... ASTM A106/A106M-10 — Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service: https://archive.org/details/gov.law.a... #SeamlessTube #EngineeringHistory #IndustrialHistory #MachineLegacy