Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High Pressure or High Temperature Service, or both.

ASTM A194 specification covers a variety of carbon, alloy, and martensitic stainless steel nuts in the size range 1/4 through 4 in. and metric M6 through M100 nominal. It also covers austenitic stainless steel nuts in the size range 1/4 in. and M6 nominal and above. These nuts are intended for high-pressure or high-temperature service, or both.

ASTM A194 Grade 4 Nut Grades

Grade Tensile Class Raw Material

ASTM A194 Grade 4 Chemical Components

Grade Material UNS
Number
C, % Mn, % Ph, % S, % Si, % Cr, % Ni, % Mo, % Ti, % Cb & Ta, % N, % Other Elements, %
4 carbon, molybdenum
  0.40-0.50 0.70-0.90 0.035 0.040 0.15-0.35   - 0.20-0.30 - - - -

ASTM A194 Grade 4 Hardness Requirement

Grade & Type Brinell Hardness Rockwell Hardness
C Scale B Scale
4, 7, 16 248-327 24 - 35 -

ASTM A194 Grade 4 Proof Load (Inch Series)

Nominal Size, inch Threads per inch Stress Area inch Proof Load, lbf
Grade 2H, 4, 7, 16
Heavy Hex Hex
1/4" 20 0.0316 4770 4300
5/16" 18 0.0524 7860 7070
3/8" 16 0.0774 11620 10460
7/16" 14 0.1063 15940 14350
1/2" 13 0.1419 21280 19160
9/16" 12 0.1820 27300 24570
5/8" 11 0.2260 33900 30510
3/4" 10 0.3340 50100 45090
7/8" 9 0.4620 69300 62370
1" 8 0.606 90900 81810
1 1/8" 8 0.7900 118500 106700
1 1/4" 8 1.0000 150000 135000
1 3/8" 8 1.2330 185000 166500
1 1/2" 8 1.492 223800 201400

ASTM A194 Grade 4 Marking

Grade Type Hot Forged or Cold Punched Nuts Nuts Machined from Bar Stock
4 4 4B