Model Number: 50060. Type and Compatibility: Bolt Threading Dies for 500B 531 541 Heads. Alloy Type and RH/LH Designation: RH High-Speed. Thread Size and TPI: M10-1.5. Thread Type: ISO Size. Ridgid 50060 Bolt Threading Dies for 500B 531 541 Heads, RH High-Speed, M10-1.5 in. mm ISO Size. Ridgid. The Ridge Tool Company. 50060.