CYLINDER TANKS FOR NITROGEN, HELIUM, ARGON SERVICE (60 CF W/CARRY HANDLE) Specification: DOT-3AL & TC-3ALM designed; ISO design cylinders are available Finish: Standard finish is brushed body with unpainted crown, shipped empty Alloy: Manufactured from high strength aluminum alloy 6061-T6; Threads: Standard thread is .750-16 UNF & 1.125-12 UNF - Taper threads are 3/4-14 NGT, 25E Our aluminum helium cylinders 40% lighter than steel cylinders