ASTM A194 Grade 2H Specification

ASTM A194 Grade 2H Specification for high tensile nuts and other internally threaded fasteners, made from heat treated carbon steel.

ASTM A194 Grade 2H is a standard material specification for high tensile nuts and other internally threaded fasteners, made from carbon steel. Grade 2H nuts can be produced by means of hot forging, cold forging or machining from heat treated bar stock. ASTM A194 specification covers requirements for chemical composition, heat treatment, hardness, proof load, etc., for Grade 2H nuts.

Chemical Composition


Element
Carbon Steel
CompositionA, %
Carbon 0.15 min
Manganese 1.00 max
Phosphorus 0.04 max
Sulfur 0.05 max
Silicon 0.40 max

AThe intentional addition of Bi, Se, Te, and Pb is not permitted.

Hardness

Grade, Size,
Diameter
Completed Nuts Sample Nut After Heat Treatment
Brinell Hardness,
BHN
Rockwell Hardness Brinell Hardness,
BHN, min
Rockwell Hardness,
HRB, min
HRC HRB
2H, To 1-1⁄2 Inch, inclusive 248 - 327 24 - 35 ... 179 89
2H, Over 1-1/2" Inch. 212 - 327 35 max 95 min 147 79

Heat Treatment: Grade 2H shall be quenched and tempered at a temperature of at least 850 °F [455 °C].

Proof Load

Nominal Size, Inch. Threads Per Inch Proof Load, lbf
Heavy HexA HexB
1/4 20 5 570 4 770
5/16 18 9 170 7 860
3/8 16 13 560 11 620
7/16 14 18 600 15 940
1/2 13 24 830 21 280
9/16 12 31 850 27 300
5/8 11 39 550 33 900
3/4 10 58 450 50 100
7/8 09 80 850 69 300
01 08 106 000 90 900
1-1/8 08 138 200 118 500
1-1/4 08 175 000 150 000
1-3/8 08 215 800 185 000
1-1/2 08 261 100 223 800

A: Based on proof stress of 175 000 psi.
B: Based on proof stress of 150 000 psi.

Nuts

Commonly Produced Grade 2H Nuts
Hex Nuts Heavy Hex Nuts Jam Nuts Heavy Hex Jam Nuts Castle Nuts
Coupling Nuts Square Nuts Thin Square Nuts All Metal Lock Nuts Dome Nuts