Production of rolled internal screw thread - uses roller which is moved axially as it is rotated and which roller has external screw thread

摘要

The rolled internal screw thread is formed in the bore of a tubular workpiece using a tool in the form of a roller with an external screw thread . The tool is rolled around the inside of the workpiece and for each full revolution of the tool it is driven axially forwards by a distance (V). The distance (V) is calculated from the formula relating the pitch (P) of the screw thread, the outside dia. of the screw thread, and the tool dia. ADVANTAGE - Produces internal screw threads of greater strength than the usual cut screw threads.