METHOD OF FORGING TERMINAL BOLTS Russian patent published in 2013 - IPC B21K1/46 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming and may be used in forging eternal bolts for rail joints at multistation automatic press in four steps. At first step, head with cylindrical section and truncated cone section with two flat faces are formed. At second step, rectangular-section head with prism-shape recess at end surface is formed. Angles of prism side faces to head end surface make 5-8 degrees. Recess height makes 0.10-0.15 of the height of finished head. At third step, head is finished to form a radial fin. Note here that recesses at end face are shaped to tetrahedral truncated pyramid. Pyramid height makes 0.20-0.30 of the bolt head height. Angle of face inclination to end face surface in plane crossing larger axis of symmetry of rectangle makes 25-35 degrees. Angle of face inclination to end face surface in plane crossing smaller axis of symmetry of rectangle makes 80-85 degrees. At fourth step, fin is cut off.

EFFECT: higher quality and efficiency.

4 dwg, 1 tbl