A194 Mechanical Properties
| Grade Identification Marking5 |
Specification |
Material |
Nominal Size, In. |
Tempering Temp. °F |
Proof Load Stress, ksi |
Hardness Rockwell |
See Note |
| Min |
Max |
 |
ASTM A194 Grade 2 |
Medium Carbon Steel |
1/4 - 4 |
0 |
150 |
159 |
352 |
1,2,3 |
 |
ASTM A194 Grade 2H |
Medium Carbon Steel, Quenched and Tempered |
1/4 - 4 |
850 |
175 |
C24 |
C38 |
1,2 |
 |
ASTM A194 Grade 2HM |
Medium Carbon Steel, Quenched and Tempered |
1/4 - 4 |
1150 |
150 |
159 |
237 |
1,2,3 |
 |
ASTM A194 Grade 4 |
Medium Carbon Alloy Steel, Quenched and Tempered |
1/4 - 4 |
1100 |
175 |
C24 |
C38 |
1,2 |
 |
ASTM A194 Grade 7 |
Medium Carbon Alloy Steel, Quenched and Tempered |
1/4 - 4 |
1100 |
175 |
C24 |
C38 |
1,2 |
 |
ASTM A194 Grade 7M |
Medium Carbon Alloy Steel, Quenched and Tempered |
1/4 - 4 |
1150 |
150 |
159 |
237 |
1,2,3 |
 |
ASTM A194 Grade 8 |
Stainless AISI 304 |
1/4 - 4 |
- |
80 |
126 |
300 |
4 |
 |
ASTM A194 Grade 8M |
Stainless AISI 316 |
1/4 - 4 |
- |
80 |
126 |
300 |
4 |
NOTES:
- The markings shown for all grades of A194 nuts are for cold formed and hot forged nuts. When nuts are machined from bar stock, the nut must additionally be marked with the letter 'B'. The letters H and M indicate heat treated nuts.
- Properties shown are those of coarse and 8-pitch thread heavy hex nuts.
- Hardness numbers are Brinell Hardness.
- Nuts that are carbide-solution treated require additional letter A - 8A or 8MA.
- All nuts shall bear the manufacturer’s identification mark. Nuts shall be legibly marked on one face to indicate the grade and process of the manufacturer. Marking of wrench flats or bearing surfaces is not permitted unless agreed upon between manufacturer and purchaser.
- Other less common grades exist, but are not listed here.
Inch Fastener Standards. 7th ed. Cleveland: Industrial Fasteners Institute, 2003. N-80 - N-81. |
