ASTM A194 Grades
Mechanical properties of fasteners made of carbon steel and alloy steel
Carbon and Alloy Steel Nuts for Bolts for High Pressure or High Temperature Service
The ASTM A194 specification covers carbon, alloy, and stainless steel nuts intended for use in high-pressure and/or high-temperature service. Unless otherwise specified, the American National Standard Heavy Hex Series (ANSI B 18.2.2) shall be used. Nuts up to and including 1-inch nominal size shall be UNC Series Class 2B fit. Nuts over 1-inch nominal size shall be either UNC Series Class 2B fit or 8 UN Series Class 2B fit. High strength ASTM A194 grade 2H nuts are common in the marketplace and are often substituted for ASTM A563 grade DH nuts due to the limited availability of DH nuts in certain diameters and finishes.
| 2 | Carbon steel Hex Nut, Heavy hex nut |
| 2H | Carbon steel Hex Nut, Heavy hex nut |
| 2HM | Carbon steel Hex Nut, Heavy hex nut |
| 4 | Carbon steel Hex Nut, Heavy hex nut |
| 7 | Carbon steel Hex Nut, Heavy hex nut |
| 7M | Carbon steel Hex Nut, Heavy hex nut |
| 8 | Stainless AISI 304 Hex Nut, Heavy hex nuts |
| 8M | Stainless AISI 316 Hex Nut, Heavy hex nuts |
| A4-70 | Stainless AISI 304 Hex Nut, Heavy hex nuts |
| A4-80 | Stainless AISI 316 Hex Nut, Heavy hex nuts |
ASTM A194 Grade 8M Chemical properties
| Property class | Chemical composition | |||||||||
| C. | MN. | SI. | P. | S. | Cr. | Ni. | Mo. | V. | Ti. | |
| 8M | 0.08 | 2.00 | 1.00 | 0.045 | 0.030 | 16.00 - 18.00 | 10.00 - 14.00 | 2.0 - 3.0 | - | - |
ASTM A194 Grade 8M Hardness properties Inch Product
| Class | Diameter, [mm] | Brinell Hardness | Rockwell Hardness | |
| C Scale | B Scale | |||
| 8M | ALL | 126-300 | 32 max | 60 min |