1. ASTM A194/A194M-2018 "High Temperature or High Pressure or High Temperature and High Pressure Nut Standard Specification" series nuts:

Common grades in the standard: Gr.2H, 2HM, 4, 6, 7, 7M, etc.

2. Applicable to: high and medium pressure valves; marine, shipbuilding, chemical, fluid engineering; pressure vessels; petrochemical equipment and other high temperature and high pressure, low temperature and high pressure equipment.

3. Optional standard sizes include: GB/T6170, GB/T6172, GB/T6175, GB/T9125 (large hexagon), GB/T1229 (large hexagon for steel structure), HG/T20634 (special), HG/T20613 (special), SH/T3404, DIN934, ISO4032, ISO4035, UNI5587 heavy duty, UNI5588, ANSI (UNC/UNF/UN) American standard coarse/fine/8-tooth permanent, ANSI/ASME B18.2.2 American heavy duty, ASME B18.2.4.1M, ASME B18.2.4.2M, ASME B18.2.4.3M, ASME B18.2.4.6M metric hexagon nuts, etc.

4. Materials: AISI1045, AISI4140, etc.

5. Surface treatment: natural color, phosphating, blackening, zinc plating (Zn), Dacrotized, Xylan coating.