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 8F Nut Grades

Grade Tensile Class Raw Material
B5 4-6% Chromium Ferritic Steel
B6 13% Chromium Ferritic Steel
B6X 13% Chromium Ferritic Steel
B7 Chromium Molybdenum Alloy Steel, Quenched & Tempered
B7M Chromium Molybdenum Alloy Steel, Quenched & Tempered
B16 Chromium-molybdenum-vanadium Alloy Steel, Quenched & Tempered
B8 Class 1 AISI 304 Stainless Steel, Carbide Solution Treated
B8 Class 2 AISI 304 Stainless Steel, Carbide Solution Treated and Strain Hardened
B8A AISI 304 Stainless Steel, Carbide solution treated in the finished condition
B8C Class 1 AISI 347 Stainless Steel, Carbide Solution Treated
B8C Class 2 AISI 347 Stainless Steel, Carbide Solution Treated and Strained Hardened
B8CA AISI 347 Stainless Steel, Carbide Solution Treated in Finished Condition
B8M Class 1 AISI 316 Stainless Steel, Carbide Solution Treated
B8M Class 2 AISI 316 Stainless Steel, Carbide Solution Treated and Strain Hardened
B8MA AISI 316 Stainless Steel, Carbide Solution Treated in Finished Condition
B8M2 AISI 316 Stainless Steel, Carbide Solution Treated and Strain Hardened
B8M3 AISI 316 Stainless Steel, Carbide Solution Treated and Strain Hardened
B8P Class 1 AISI 305 Stainless Steel, Carbide Solution Treated
B8P Class 2 AISI 305 Stainless Steel, Carbide Solution Treated and Strain Hardened
B8PA AISI 305 Stainless Steel, Carbide Solution Treated in Finished Condition
B8N AISI 304N Stainless Steel, Carbide Solution Treated
B8N AISI 304N Stainless Steel, Carbide Solution Treated and Strain Hardened
B8MLCuN AISI 304N Stainless Steel, Carbide Solution Treated
B8MLCuN UNS S31254 Stainless Steel, Carbide Solution Treated and Strain Hardened
B8MLCuNA UNS S31254 Stainless Steel, Carbide Solution Treated
B8T Class 1 AISI 321 Stainless Steel, Carbide Solution Treated
B8T Class 2 AISI 321 Stainless Steel, Carbide Solution Treated and Strain Hardened
B8TA AISI 321 Stainless Steel, Carbide Solution Treated in Finished Condition
B8R Nitronic 50/UNS S20910 Stainless Steel, Carbide Solution Treated
B8RA Nitronic 50/UNS S20910 Stainless Steel, Carbide Solution Treated in Finished Condition
B8S Nitronic 60/UNS S21800 Stainless Steel, Carbide Solution Treated
B8SA Nitronic 60/UNS S21800 Stainless Steel, Carbide Solution Treated
B8LN AISI 304LN Stainless Steel, Carbide Solution Treated
B8LNA AISI 304LN Stainless Steel, Carbide Solution Treated in Finished Condition
B8MLN AISI 316LN Stainless Steel, Carbide Solution Treated
B8MLNA AISI 316LN Stainless Steel, Carbide Solution Treated in Finished Condition
B8CLN AISI 347LN Stainless Steel, Carbide Solution Treated
B8CLNA AISI 347LN Stainless Steel, Carbide Solution Treated in Finished Condition

ASTM A194 Grade 8F Chemical Components

Grade Material UNS
Number
C, % Mn, % Ph, % S, % Si, % Cr, % Ni, % Mo, % Ti, % Cb & Ta, % N, % Other Elements, %
1 Carbon   0.15 min 1.000 0.040 0.050 0.400 - - - - - - -
2, 2HM, & 2H Carbon   0.40 min 1.000 0.040 0.050 0.400 - - - - - - -
2H Carbon   0.40 min 1.000 0.040 0.050 0.400 - - - - - - -
2HM Carbon   0.40 min 1.000 0.040 0.050 0.400 - - - - - - -
3 Type 501   0.10 min 1.000 0.040 0.030 1.000 4.0-6.0 - 0.40-0.65 - - - -
4 carbon, molybdenum
  0.40-0.50 0.70-0.90 0.035 0.040 0.15-0.35   - 0.20-0.30 - - - -
6 Type 410 S41000 0.150 1.000 0.040 0.030 1.000 11.5-13.5 - - - - - -
6F Type 416 S416000 0.150 1.250 0.060 0.15min 1.000 12.0-14.0 -   - - - -
6F Type 416Se S41623 0.150 1.250 0.060 0.060 1.000 12.0-14.0 -   - - - Selenium, 0.15 min
7, 7M Type 4140, 4142, 4145, 4140H, 4142H, 4145H   0.37-0.49 0.65-1.10 0.035 0.040 0.15-0.35 0.75-1.2 - 0.15-0.25 - - - -
8 Type 304 S30400 0.080 2.000 0.045 0.030 1.000 18.0-20.0 8.0-11.0   - - - -
8A Type 304   0.080 2.000 0.045 0.030 1.000 18.0-20.0 8.0-11.0   - - - -
8C Type 347 S34700 0.080 2.000 0.045 0.030 1.000 17.0-19.0 9.0-12.0   - 10 x Carbon Content, min - -
8CA Type 347 S34700 0.080 2.000 0.045 0.030 1.000 17.0-19.0 9.0-12.0   - 10 x Carbon Content, min - -
8CLN, 8CLNA Type 347LN S34751 0.0005-0.020 2.000 0.045 0.030 1.000 17.0-19.0 9.0-13.0   - 0.20-0.50, 15 x Carbon Content,min 0.06-0.10 -
8M, 8MA Type 316 S31600 0.080 2.000 0.045 0.030 1.000 16.0-18.0 10.0-14.0 2.00-3.00 - - - -
8T, 8TA Type 321 S32100 0.080 2.000 0.045 0.030 1.000 17.0-19.0 9.0-12.0 - 5 x (C+N),Min – 0.70 max - 0.100 -
8F, 8FA Type 303 S30300 0.150 2.000 0.200 0.150 1.000 17.0-19.0 8.0-10.0 - - - - -
8F, 8FA Type 303 Se S30323 0.150 2.000 0.200 0.06 1.000 17.0-19.0 8.0-10.0 - - - - Selenium, 0.15 min
8P, 8PA Type 305 with restricted carbon S30500 0.080 2.000 0.045 0.030 1.000 17.0-19.0 11.0-13.0 - - - - -
8N, 8NA Type 304N S30451 0.080 2.000 0.045 0.030 1.000 18.0-20.0 8.0-11.0 - - - 0.10-0.16 -
8LN, 8LNA     0.030 2.000 0.045 0.030 1.000 18.0-20.0 8.0-11.0 - - - 0.10-0.16 -
8MN, 8MNA Type 316N S31651 0.080 2.000 0.045 0.030 1.000 16.0-18.0 10.0-13.0 2.0-3.0 - - 0.10-0.16 -
8MLN, 8MLNA Type 316LN S31653 0.030 2.000 0.045 0.030 1.000 16.0-18.0 10.0-13.0 2.0-3.0 - - 0.10-0.16 -
8R, 8RA XM19 S20910 0.060 4.0-6.0 0.045 0.030 1.000 20.5-23.5 11.5-13.5 1.50-3.0 - 0.10-0.30 0.20-0.40 Vanadium,
0.10-0.30
8S, 8SA   S21800 0.100 7.0-9.0 0.060 0.030 3.5-4.5 16.0-18.0 8.0-9.0 - - - 0.08-0.18 -
8MLCuN, 8MLCuNA S31254 S31254 0.020 1.000 0.030 0.010 0.800 19.5-20.5 17.5-18.5 6.0-6.5 - - 0.18-0.25 Copper
0.50-1.00
9C, 9CA N08367 N08367 0.030 2.000 0.040 0.030 1.000 20.0-22.0 23.5-25.5 6.0-7.0 - - 0.18-0.25 Copper
0.75
16 Chromium Molybdenum Vanadium   0.36-0.47 0.45-0.70 0.035 0.040 0.15-0.35 0.80-1.15   0.50-0.65 - - - Vanadium 0.25-0.35
AluminumB 0.015

ASTM A194 Grade 8F Hardness Requirement

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

ASTM A194 Grade 8F 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 8F Marking

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