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 8 Nut Grades

Grade Tensile Class Raw Material

ASTM A194 Grade 8 Chemical Components

Grade Material UNS
Number
C, % Mn, % Ph, % S, % Si, % Cr, % Ni, % Mo, % Ti, % Cb & Ta, % N, % Other Elements, %
8 Type 304 S30400 0.080 2.000 0.045 0.030 1.000 18.0-20.0 8.0-11.0   - - - -

ASTM A194 Grade 8 Hardness Requirement

Grade & Type Brinell Hardness Rockwell Hardness
C Scale B Scale
8 126-300 32 max 60 min

ASTM A194 Grade 8 Proof Load (Inch Series)

Nominal Size, inch Threads per inch Stress Area inch Proof Load, lbf
All Types of Grade 8
Heavy Hex Hex
1/4" 20 0.0316 5570 4770
5/16" 18 0.0524 9170 7860
3/8" 16 0.0774 13560 11620
7/16" 14 0.1063 18600 15940
1/2" 13 0.1419 24830 21280
9/16" 12 0.1820 31850 27300
5/8" 11 0.2260 39550 33900
3/4" 10 0.3340 58450 50100
7/8" 9 0.4620 80850 69300
1" 8 0.606 106000 90900
1 1/8" 8 0.7900 138200 118500
1 1/4" 8 1.0000 175000 150000
1 3/8" 8 1.2330 215800 185000
1 1/2" 8 1.492 261100 223800

ASTM A194 Grade 8 Marking

Grade Type Hot Forged or Cold Punched Nuts Nuts Machined from Bar Stock
8 8 8B