Grade and Material Identification Markings
Identification
Grade
Mark |
Specification |
Fastener
Description |
Material |
Nominal
Size
Range
(inch) |
Mechanical Properties |
Yield
Stremgth
(min. psi) |
Tensile
Strength
(min. psi) |
Proof
Load
(psi) |
No Grade Mark |
ASTM A307 Grades A & B |
Bolts, Screws,Studs |
Low CarbonSteel |
¼ thru 4 |
|
60,000 |
|
No Grade Mark |
SAE J429
Grade 2 |
Bolts, Screws, Studs |
Low or Medium Carbon Steel |
¼ thru ¾
Over 1 to 1 1/2 |
57,000
36,000
|
74,000
60,000
|
|
|
SAE J429
Grade 5 |
Bolts, Screws, Studs |
Medium Carbon Steel Quenched and Tempered |
¼ thru 1
Over 1 to 1 ½
|
92,000
81,000
|
120,000
105,000
|
|
|
ASTM A449 |
Bolts, Screws, Studs |
Medium Carbon Steel Quenched and Tempered |
¼ thru 1
Over 1 to 1 ½
Over 1 ½ thru 3
|
92,000
81,000
58,000
|
120,000
105,000
90,000
|
|
A325 |
ASTM A325
Type 1 |
High Strength Structural Bolts |
Medium Carbon Steel Quenched and Tempered |
½ thru 1
1 1/8 thru 1 ½
|
92,000
81,000
|
120,000
105,000
|
|
|
SAE J429
Grade 8 |
Bolts, Screws, Studs |
Medium Carbon AlloySteel Quenched And Tempered |
¼ thru 1 ½ |
130,000 |
150,000 |
|
A490 |
ASTM A490 |
High Strength Structural Bolts |
Alloy Steel Quenched And Tempered |
½ thru 1 ½ |
130,000 |
150,000 Min
170,000 Max
|
|
B6 |
ASTM A193 |
Bolts, Screws, Studs
For High Temperature
Service |
AISI 410 |
¼ thru 4 |
85,000 |
110,000 |
|
B7 |
ASTM A193 |
Bolts, Screws, Studs For High Temperature Service |
AISI 4140
4142 or
4145 |
¼ thru 2 ½
Over 2 ½ thru 4
Over 4 thru 7
|
105,000
95,000
75,000
|
125,000
115,000
100,000
|
|
B8 |
ASTM A193
ASTM A320
|
Bolts, Screws, Studs
For High or Low-Temperature Service |
AISI 304,
Carbide Solution
Treated |
¼ and larger |
30,000 |
75,000 |
|
L7 |
ASTM A320 |
Bolts, Screws, Studs for
Low-Temperature Service |
AISI 4140, 4142 or
4145 Quenched and Tempered |
¼ thru 2 ½ |
105,000 |
125,000 |
|
2H |
ASTM A194 |
Hot or Cold Forged Nuts
For High-Pressure & Hi
gh Temperature
Service |
Carbon Steel,
Heat Treated |
¼ and larger |
|
|
175,000
150,000
|
8 |
ASTM A194 |
Hot or Cold Forged Nuts
For High-Pressure &
High Temperature
Service |
AISI 304 |
¼ and larger |
|
|
80,000
75,000
|
8B |
ASTM A194 |
Nuts Machined from Bar For High-Pressure & High Temperature
Service |
AISI 304 |
¼ and larger |
|
|
80,000
75,000
|
8C |
ASTM A194 |
Hot or Cold Forged Nuts For High Pressure &High Temperature
Service |
AISI 347 |
¼ and larger |
|
|
80,000
75,000
|
8M |
ASTM A194 |
Hot or Cold Forged Nuts For High Pressure & High Temperature
Service |
AISI 316 |
¼ and larger |
|
|
80,000
75,000
|
8T |
ASTM A194 |
Hot or Cold Forged Nuts For High Pressure & High Temperature
Service |
AISI 321 |
¼ and larger |
|
|
80,000
75,000
|
|
