Retained Mandrel
The retained mandrel for the production of large-sized seamless steel pipe is used in sectional structure. Its working section is exposed to complex and huge surface pressure as well as thermal cold-hot fatigue, whereas its connection part has to withstand mechanical forces during the pressing process.
The working part of the retained mandrel adopts H13 hot-work die steel. The many production processes include smelting, forging, rough machining, heat treatment, semi-finished & finished machining, chrome plating and phosphate treatment.
Mandrel Bar
Material: Optimized hot-die steel H13
Diameter: ~400mm Length: 10~18m
Hardness: 60-62HRC Chrome plating
Thickness: 0.045-0.055mm
