A694:
This specification covers carbon and alloy steel forgings for pipe flanges, fittings, valves, and parts for high-pressure transmission service. A chemical heat analysis of the steel shall be made, and the steel shall conform to specified chemical composition requirements.
1. Scope
1.1 This specification covers forged or rolled steel pipe flanges, forged fittings, valves, and parts suitable for use with high-strength transmission-service pipe. Included are flanges, fittings, and similar parts
A860:
This specification covers wrought high-strength low-alloy butt-welding steel fittings of seamless and electric fusion-welded construction for applications in high-pressure gas and oil transmission and distribution systems. Starting materials shall consist of plate, sheet, forgings, forging quality bar, and seamless or fusion-welded tubular products with filler metal added. Materials shall be heat treated by normalizing, quenching, and tempering or stress relieving. Specimens shall conform to required values of chemical composition and mechanical properties, namely: yield strength, tensile strength, elongation, notch toughness, and hardness. This specification does not require hydrostatic testing
1. Scope
1.1 This specification covers wrought high-strength ferritic steel butt-welding fittings of seamless and electric fusion-welded construction
So A694 is for one-piece forged or rolled items made from carbon and alloy steels. A860 is for formed and welded items made from a certain sub-group of steels called "High Strength, Low Alloy" steels. Items produced to these specs possibly would have different pressure limitations.
