Comprehensive analysis of Inconel 601 (UNS N06601) seamless pipes under ASTM B163 standard 1. Core requirements of ASTM B163 ASTM B163 is a specification for nickel and nickel alloy seamless condenser and heat exchanger tubes, covering 26 alloys including UNS N06601 (Inconel 601). Its core requirements include: Dimensions and Tolerances : Outside diameter : ≤3 inches (76.2 mm),