• Call Us: + (022) 67437577

ASTM 193/194/A320Specifications

ASTM 193 Grades

B7 Alloy steel, AISI 4140/4142 quenched and tempered
B8 Class 1 Stainless steel, AISI 304, carbide solution treated.
B8M Class 1 Stainless steel, AISI 316, carbide solution treated.
B8 Class 2 Stainless steel, AISI 304, carbide solution treated, strain hardened
B8M Class 2 Stainless steel, AISI 316, carbide solution treated, strain hardened

Mechanical Properties


Grade Size Tensile ksi, min Yield, ksi, min Elong, %, min RA % min
B7 Up to 2-1/2 125 105 16 50
2-5/8 - 4 115 95 16 50
4-1/8 - 7 100 75 18 50
B8 Class 1 All 75 30 30 50
B8M Class 1 All 75 30 30 50
B8 Class 2 Up to 3/4 125 100 12 35
7/8 - 1 115 80 15 35
1-1/8 - 1-1/4 105 65 20 35
1-3/8 - 1-1/2 100 50 28 45
B8M Class 2 Up to 3/4 110 95 15 45
7/8 - 1 100 80 20 45
1-1/8 - 1-1/4 95 65 25 45
1-3/8 - 1-1/2 90 50 30 45

Recommended Nuts and Washers


Grade Nuts Washers
B7 A194 Grade 2H F436
B8 Class 1 A194 Grade 8 SS304
B8M Class 1 A194 Grade 8M SS316
B8 Class 2 A194 Grade 8, strain hardened SS304
B8M Class 2 A194 Grade 8M, strain hardened SS316

ASTM A 194 GRADE, Mechanical Properties, Grade Identification Markings


Grade Identification Marking5 Specification Material Nominal Size, In. Tempering Temp. °F Proof Load Stress, ksi Hardness Rockwell See Note
Min Max
2 ASTM A194 Grade 2 Medium Carbon Steel 1/4 - 4 1000 150 159 352 1,2,3
2H ASTM A194 Grade 2H Medium Carbon Steel, Quenched and Tempered 1/4 - 4 1000 175 C24 C38 1,2
2HM ASTM A194 Grade 2HM Medium Carbon Steel, Quenched and Tempered 1/4 - 4 1000 150 159 237 1,2,3
4 ASTM A194 Grade 4 Medium Carbon Alloy Steel, Quenched and Tempered 1/4 - 4 1100 175 C24 C38 1,2
7 ASTM A194 Grade 7 Medium Carbon Alloy Steel, Quenched and Tempered 1/4 - 4 1100 175 C24 C38 1,2
7M ASTM A194 Grade 7M Medium Carbon Alloy Steel, Quenched and Tempered 1/4 - 4 1100 150 159 237 1,2,3
8 ASTM A194 Grade 8 Stainless AISI 304 1/4 - 4 - 80 126 300 4
8M ASTM A194 Grade 8M Stainless AISI 316 1/4 - 4 - 80 126 300 4


ASTM 194 Nut Dimensions


Nominal Size  F C H Weight
Width Across Flats  Width Across Corners Thickness Per Nut
Basic Max Min Max Min Basic Max Min  
3/8 11/16 0.688 0.669 0.794 0.763 23/64 0.377 0.341 0.03
1/2 7/8 0.875 0.850 1.010 0.969 31/64 0.504 0.464 0.07
5/8 1-1/16 1.062 1.031 1.227 1.175 39/64 0.631 0.587 0.12
3/4 1-1/4 1.250 1.212 1.443 1.382 47/64 0.758 0.710 0.20
7/8 1-7/16 1.438 1.394 1.660 1.589 55/64 0.885 0.833 0.30
1 1-5/8 1.625 1.575 1.876 1.796 63/64 1.012 0.956 0.43
1-1/8 1-13/16 1.812 1.756 2.093 2.002 1-7/64 1.139 1.079 0.59
1-1/4 2 2.000 1.938 2.309 2.209 1-7/32 1.251 1.187 0.79
1-3/8 2-3/16 2.188 2.119 2.526 2.416 1-11/32 1.378 1.310 1.02
1-1/2 2-3/8 2.375 2.300 2.742 2.622 1-15/32 1.505 1.433 1.31
1-5/8 2-9/16 2.562 2.481 2.959 2.828 1-19/32 1.632 1.556 1.62
1-3/4 2-3/4 2.750 2.662 3.175 3.035 1-23/32 1.759 1.679 2.04
1-7/8 2-15/16 2.938 2.844 3.392 3.242 1-27/32 1.886 1.802 2.41
2 3-1/8 3.125 3.025 3.608 3.449 1-31/32 2.013 1.925 2.99
2-1/4 3-1/2 3.500 3.388 4.041 3.862 2-13/64 2.251 2.155 4.19
2-1/2 3-7/8 3.875 3.750 4.474 4.275 2-29/64 2.505 2.401 5.64
2-3/4 4-1/4 4.250 4.112 4.907 4.688 2-45/64 2.759 2.647 7.38
3 4-5/8 4.625 4.475 5.340 5.102 2-61/64 3.013 2.893 9.50
3-1/4 5 5.000 4.838 5.774 5.515 3-3/16 3.252 3.124 11.94
3-1/2 5-3/8 5.375 5.200 6.207 5.928 3-7/16 3.506 3.370 15.26
3-3/4 5-3/4 5.750 5.562 6.640 6.341 3-11/16 3.760 3.616 18.12
4 6-1/8 6.125 5.925 7.073 6.755 3-15/16 4.014 3.862 21.80

Dimensions per ASME B18.2.2 1987 (1999)



ASTM A320 Grades


L7 Alloy steel, AISI 4140/4142 Quenched and tempered
L43 Alloy steel, AISI 4340 Quenched and tempered
B8 Class 1 Stainless steel, AISI 304, carbide solution treated
B8M Class 1 Stainless steel, AISI 316, carbide solution treated
B8 Class 2 Stainless steel, AISI 304, carbide solution treated, strain hardened
B8M Class 2 Stainless steel, AISI 316, carbide solution treated, strain hardened


Mechanical Properties


Grade Size Tensile,
ksi, min
Yield,
ksi, min
Charpy Impact
20-ft-lbf
@ temp
Elong,
%, min
RA, %, min
L7 Up to 21/2 125 105 -150° F 16 50
L43 Up to 4 125 105 -150° F 16 50
B8
Class 1
All 75 30 N/A 30 50
B8M
Class 1
All 75 30 N/A 30 50
B8
Class 2
Up to 3/4 125 100 N/A 12 35
7/8 - 1 115 80 N/A 15 35
11/8 - 11/4 105 65 N/A 20 35
13/8 - 11/2 100 50 N/A 28 45
B8M
Class 2
Up to 3/4 110 95 N/A 15 45
7/8 - 1 100 80 N/A 20 45
11/8 - 11/4 95 65 N/A 25 45
13/8 - 11/2 90 50 N/A 30 45

Recommended Nuts and Washers


Grade Nuts Washers
L7 A194 Grade 4 or 7 F436
L43 A194 Grade 4 or 7 F436
B8 Class 1 A194 Grade 8 SS304
B8M Class 1 A194 Grade 8M SS316
B8 Class 2 A194 Grade 8, strain hardened SS304
B8M Class 2 A194 Grade 8M, strain hardened SS316