ASTM A194 Grade 16 Specification

ASTM A194 Grade 16 Specification for high tensile nuts and other internally threaded fasteners, made from heat treated chromium-molybdenum-vanadium steel.

ASTM A194 Grade 16 is a standard material specification for high tensile nuts and other internally threaded fasteners, made from chromium-molybdenum-vanadium steel. Grade 16 nuts can be produced by means of hot forging, cold forging and followed by quenched-tempering or machining from heat treated bar stock. ASTM A194 specification covers requirements for chemical composition, heat treatment, hardness, proof load, etc., for Grade 16 nuts.

Chemical Composition


Element		 Alloy Steel
Chromium Molybdenum Vanadium Steel
CompositionA, %
Carbon 0.36 - 0.47
Manganese 0.45 - 0.70
Phosphorus 0.035 max
Sulfur 0.040 max
Silicon 0.15 - 0.35
Chromium 0.80 - 1.15
Molybdenum 0.50 - 0.65
Vanadium 0.25 - 0.35
Aluminum 0.015 maxB

A: The intentional addition of Bi, Se, Te, and Pb is not permitted.
B: Total aluminum, soluble and insoluble.

Hardness

Grade
Type		 Completed Nuts Sample Nut After Heat Treatment
Brinell Hardness,
BHN, min		 Rockwell Hardness Brinell Hardness,
BHN, min		 Rockwell Hardness,
HRB, min
HRC, min HRB, min
16 248 - 327 24 - 35 ... 201 94

Heat Treatment: Quenched & Tempered at minimum temperature 1200º F [650º 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 16 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