scope:

This standard covers pressure-temperature ratings, dimensions, tolerances, marking and material requirements for forged carbon and alloy steel fittings both socket-welding and threaded, as illustrated in Tables 4 through 7 inclusive.

Types of fittings covered by this standard are shown in Table 1, by class and size range.

Fittings shown in Tables 4 through 7 and A4 through A7 may be made with combinations of socket-welding and threaded ends, with special threads, or with special counterbores by agreement between the manufacturer and the purchaser. When such fittings meet all other stipulations of this standard, they may be considered as conforming thereto, provided they are appropriately marked (See Note under Section 4).