ASTM A193

The A193 specification is often used in petroleum and chemical construction industry for alloy steel and stainless steel bolting materials for high temperature or high pressure service. The A193 specification includes fasteners intended for use in valves, flanges, fittings, and many other applications. 

Grades

B7AISI 4140/4142 Quenched and tempered
B8 Class 1 AISI 304, carbide solution treated
B8 Class 2 AISI 304, carbide solution treated, strain hardened
B8M Class 1 AISI 316, carbide solution treated
B8M Class 2 AISI 316, carbide solution treated, strain hardened

 

Mechanical Properties

GradeSizeTensile ksi, minYield, ksi, minElong, %, minRA % 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
7/8/2001 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
7/8/2001 100 80 20 45
1-1/8 - 1-1/4 95 65 25 45
1-3/8 - 1-1/2 90 50 30 45
B16 Up to 2-1/2 125 105 18 50
2-5/8 - 4 110 95 17 45
4-1/8 - 7 100 85 16 45

 

Material Chemical Composition

ElementB7 (AISI 4140)B8 (AISI 304)B8M (AISI 316)B16 (AISI 4140)
Carbon 0.37 - 0.49% 0.08% max 0.08% max 0.37 - 0.49%
Manganese 0.65 - 1.10% 2.00% max 2.00% max 0.65 - 1.10%
Phosphorus, max 0.04% 0.05% 0.05% 0.04%
Sulfur, max 0.04% 0.03% 0.03% 0.04%
Silicon 0.15 - 0.35% 1.00% max 1.00% max 0.15 - 0.35%
Chromium 0.75 - 1.20% 18.0 - 20.0% 16.0 - 18.0% 0.75 - 1.20%
Nickel   8.0 - 11.0% 10.0 - 14.0%  
Molybdenum 0.15 - 0.25%   2.00 - 3.00% 0.15 - 0.25%

 

Recommended Nuts, Bolts & Washers

Bolt GradeNutsWashers
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 SS304
B8M Class 2 A194 Grade 8M SS316


ASTM A320

ASTM A320 covers high end alloy steel bolts used in the oil and gas industry including fasteners used in valves, flanges, fittings and other components.

Grades

L7AISI 4140/4142 Quenched and tempered
L43 AISI 4340 Quenched and tempered
B8 Class 1 AISI 304, carbide solution treated
B8 Class 2 AISI 304, carbide solution treated, strain hardened
B8M Class 1 AISI 316, carbide solution treated
B8M Class 2 AISI 316, carbide solution treated, strain hardened

 

Mechanical Properties

GradeSizeTensile ksi, minYield, ksi, minElong, %, minRA % minCharpy Impact
20-ft-lbf
@ temp
L7 Up to 2-1/2 125 105 16 50 -150° F
L43 Up to 4 125 105 16 50 -150° F
B8 Class 1 All 75 30 30 50 N/A
B8 Class 2 Up to 3/4 125 100 12 35 N/A
7/8/2001 115 80 15 35 N/A
1-1/8 - 1-1/4 105 65 20 35 N/A
1-3/8 - 1-1/2 100 50 28 45 N/A
B8M Class 1 All 75 30 30 50 N/A
B8M Class 2 Up to 3/4 110 95 15 45 N/A
7/8/2001 100 80 20 45 N/A
1-1/8 - 1-1/4 95 65 25 45 N/A
1-3/8 - 1-1/2 90 50 30 45 N/A

 

Material Chemical Composition

ElementL7 (AISI 4140)L43 (AISI 4340)B8 (AISI 304)B8M (AISI 316)
Carbon 0.37 - 0.49% 0.38 - 0.43% 0.08% max 0.08% max
Manganese 0.65 - 1.10% 0.75 - 1.00% 2.00% max 2.00% max
Phosphorus, max 0.04% 0.04% 0.05% 0.05%
Sulfur, max 0.04% 0.04% 0.03% 0.03%
Silicon 0.15 - 0.35% 0.15 - 0.35% 1.00% max 1.00% max
Chromium 0.75 - 1.20% 0.70 - 0.90% 18.0 - 20.0% 16.0 - 18.0%
Nickel   1.65 - 2.00% 8.0 - 11.0% 10.0 - 14.0%
Molybdenum 0.15 - 0.25% 0.02 - 0.30%   2.00 - 3.00%

 

Recommended Nuts & Washers 

Bolt GradeNutsWashers
L7 A194 Grade 4 or 7 F436
L43 A194 Grade 4 or 7 F436
B8 Class 1 A194 Grade 8 SS304
B8 Class 2 A194 Grade 8 SS304
B8M Class 1 A194 Grade 8M SS316
B8M Class 2 A194 Grade 8M SS316