Patent ID: 8813533

Claim:
A method of cold-forming workpieces in a multi-die machine comprising the steps of receiving a workpiece at a workstation, providing a set of tooling including die and tool units respectively supported on a die breast and slide, one of the tooling units being arranged to slide a limited distance on its supporting structure, a spring arranged to bias said one tooling unit towards the other tooling unit, the end faces of the die and tool units being arranged with mutual contact areas that are smooth, dispensing extrusion/cooling oil at the workstation in a manner that coats the exterior of the workpiece, the die and tool units being arranged such that their end faces engage before the slide reaches its forwardmost position while the spring maintains a contact force at their end faces, the relationship of the spring force and contact area being such that the end faces seal against escape of oil from the cavity formed by the die and tool units whereby forming pressure is imparted to the workpiece to produce a consequent hydrostatic pressure in the oil in the cavity that facilitates a high reduction in cross-section of the workpiece exceeding 55%.