ASTM, SAE and ISO Grade Markings for Steel Fasteners

Download a complimentary PDF of our Fastener Markings chart. Contact American Fastener with any questions or for a custom quote.

adobe-pdf-logo

IdentificationGrade Mark Specification FastenerDescription Material Nominal SizeRange (in.) Mechanical Properties
Proof
Load
(psi)
Yield
Strength
Min (psi)
Tensile
Strength
Min (psi)
NoGradeMark SAE J429Grade 1 Bolts,Screws,Studs Low or
Medium Carbon Steel
1/4 thru
1-1/2
33,000 36,000 60,000
ASTM A307Grades A&B Low Carbon
Steel
1/4 thru 4
SAE J429Grade 2 Low or
Medium Carbon Steel
1/4 thru
3/4 Over 3/4 to 1-1/2
55,00033,000 57,00036,000 74,00060,000
NoGradeMark SAE J429Grade 4 Studs Medium
Carbon Cold Drawn Steel
1/4 thru
1-1/2
100,000 115,000
B5 ASTM A193Grade B5 AISI 501 1/4 Thru 4 80,000 100,000
B6 ASTM A193Grade B6 AISI 410 85,000 110,000
B7 ASTM A193Grade B7 AISI 4140,
4142, OR 4105
1/4 thru 2-1/2Over 2-1/2 thru 4Over 4 thru 7 —- 105,00095,00075,000 125,000115,000100,000
B16 ASTM A193Grade B16 CrMoVa
Alloy Steel
105,00095,00085,000 125,000115,000100,000
B8 ASTM A193Grade B8 AISI 304 1/4 and larger 30,000 75,000
B8C ASTM A193Grade B8C AISI 347
B8M ASTM A193Grade B8M AISI 316
B8T ASTM A193Grade B8T Bolts,Screws,Studs for High-Temperature Service AISI 321 1/4 and
larger
30,000 75,000
B8 ASTM A193Grade B8 AISI 304Strain Hardened 1/4 thr 3/4Over 3/4 thru 1Over 1 thru 1-1/4Over 1-1/4 thru 1-1/2 —— 100,00080,00065,000

50,000

125,000115,000105,00

0100,000

B8C ASTM A193Grade B8C AISI 347Strain Hardened
B8M ASTM A193Grade B8M AISI 316Strain Hardened 95,00080,00065,000

50,000

110,000100,00095,00

090,000

B8T ASTM A193Grade B8T AISI 321Strain Hardened 100,00080,00065,000

50,000

125,000115,000105,000

100,000

L7 ASTM A320Grade L7 Bolts,Screws,Studs for Low-Temperature Service AISI 4140,4142 or 4145 1/4 thru 2-1/2 105,000 125,000
L7A ASTM A320Grade L7A AISI 4037
L7B ASTM A320Grade L7B AISI 4137
L7C ASTM A320Grade LC7 AISI 8740
L43 ASTM A320Grade L43 AISI 4340 1/4 thru 4 105,000 125,000
B8 ASTM A320Grade B8 Bolts,Screws,Studs for Low-Temperature Service AISI 304 1/4 and larger 30,000 75,000
B8C ASTM A320Grade B8C AISI 347
B8T ASTM A320Grade B8T AISI 321
B8F ASTM A320Grade B8F AISI 303or 303Se
B8M ASTM A320Grade B8M AISI 316
B8 ASTM A320Grade B8 AISI 304 1/4 thru 3/4Over 3/4 thru 1Over 1 thru 1-1/4Over 1-1/4 thru 1-1/2 —— 100,00080,00065,00

50,00

100,00080,00065,00

50,00

B8C ASTM A320Grade B8C AISI 347
B8F ASTM A320Grade B8F AISI 303or 303Se
B8M ASTM A320Grade B8M AISI 316
B8T ASTM A320Grade B8T AISI 321
SAE J429Grade 5 Bolts,Screws,Studs Medium Carbon Steel, Quenched and Tempered 1/4 thru 1Over 1 to 1-1/2 85,00074,000 92,00081,000 120,000105,000
ASTM A449 1/4 thru 1Over 1 to 1-1/2Over 1-1/2 thru 3 85,00074,000

55,000

92,00081,00058,000 120,000105,00090,000
SAE J429Grade 5.1 Sems Low or
Medium Carbon Steel, Quenched and Tempered
No. 6thru 3/8 85,000 120,000
SAE J429Grade 5.2 Bolts,Screws,Studs Low Carbon
Martensitic Steel, Quenched and Tempered
1/4 thru 1 85,000 92,000 120,000
A325 ASTM A325Type 1 High StrengthStructural Bolts Medium
Carbon Steel, Quenched and Tempered
1/2 thru 11-1/8 thru 1-1/2 85,00074,000 92,00081,000 120,000105,000
A325 ASTM A325Type 2 Low Carbon
Martensitic Steel, Quenched and Tempered
1/2 thru 1 85,000 92,000 120,000
A325 ASTM A325Type 3 Atmospheric
Corrosion Resisting Steel, Quenched and Tempered
1/2 thru 11-1/8 thru 1-1/2 85,00074,000 92,00081,000 120,000105,000
BB ASTM A354Grade BB Bolts,Studs Alloy Steel, Quenched and Tempered 1/4 thru 2-1/22-3/4 thru 4 80,00075,000 83,00078,000 105,000100,000
BC ASTM A354Grade BC 105,00095,000 109,00099,000 125,000115,000
SAE J429Grade 7 Bolts,Screws, Medium
Carbon Alloy Steel, Quenched and Tempered
4
1/4 thru
1-1/2
105,000 115,000 133,000
SAE J429Grade 8 Bolts,Screws,Studs Medium
Carbon Alloy Steel, Quenched and Tempered
1/4 thru 1-1/2 120,000 130,000 150,000
ASTM A354Grade BD Alloy
Steel, Quenched and Tempered
4
No GradeMark SAE J429Grade 8.1 Studs Medium
Carbon Alloy or SAE 1041 Modified Elevated Temperature
Drawn Steel
1/4 thru
1-1/2
120,000 130,000 150,000
A490 ASTM A490 High
Strength
Structural Bolts
Alloy
Steel, Quenched and Tempered
1/2 thru
1-1/2
120,000 130,000 150,000
min
170,000 max
No GradeMark ISO R898Class 4.6 Bolts,Screws,Studs Medium Carbon Steel, Quenched and Tempered All Sizesthru 1-1/2 33,000 36,000 60,000
No GradeMark ISO R898Class 5.8 55,000 57,000 74,000
8.8or88 ISO R898Class 8.8 Alloy Steel, Quenched and Tempered 85,000 92,000 120,000
10.9or109 ISO R898Class 10.9 120,000 130,000 150,000

 

 

FASTENER IDENTIFICATION
MARKING

 

GradeIdentificationMarking Specification Material Nominal SizeIn. ProofLoadStressksi HardnessRockwell SeeNote
Min Max
No Mark ASTM A563
- Grade 0
Carbon
Steel
1/4 thru
1-1/2
69 B55 C32 3,4
ASTM A563
- Grade A
Carbon
Steel
1/4 thru
1-1/2
90 B68 C32 3,4
ASTM A563 – Grade B Carbon Steel 1/4 thru 1 120 B69 C32 3,4
over 1
thru 1-1/2
105
ASTM A563
- Grade C
Carbon
Steel
May be Quenchedand Tampered
1/4 thru 4 144 B78 C38 5
ASTM A563
- Grade C3
AtmosphericCorrosionResistant SteelMay be Quenchedand Tampered 1/4 thru 4 144 B78 C38 5,9
ASTM A563
- Grade D
Carbon
Steel
May be Quenchedand Tampered
1/4 thru 4 150 B84 C38 6
ASTM A563
- Grade DH
Carbon
Steel
Quenchedand Tampered
1/4 thru 4 175 C24 C38 6
ASTM A563
- Grade DH3
AtmosphericCorrosionResistant Steel,Quenchedand Tampered 1/4 thru 4 175 C24 C38 5,9
ASTM A194
- Grade 1
Carbon
Steel
1/4 thru 4 130 B70 7
ASTM A194
- Grade 2
Medium
Carbon
Steel
1/4 thru 4 150 159 352 7,8
ASTM A194
- Grade 2H
Medium
Carbon
Steel, Quenchedand Tempered
1/4 thru 4 175 C24 C38 7
ASTM A194
- Grade 2HM
Medium
Carbon
Steel, Quenchedand Tempered
1/4 thru 4 150 159 237 7,8
ASTM A194
- Grade 4
Medium
Carbon
Alloy Steel,Quenchedand Tempered
1/4 thru 4 175 C24 C38 7
ASTM A194
- Grade 7
Medium
Carbon
Alloy Steel,Quenchedand Tempered
1/4 thru 4 175 C24 C38 7
ASTM A194
- Grade 7M
Medium
Carbon
Alloy Steel,Quenchedand Tempered
1/4 thru 4 150 159 237 7
See Note 1,2 10

 

NOTES:

  1. In addition to the indicated grade
    marking, all grades, except A563 grades O, A and B, must
    be marked for manufacturer identification.
  2. The markings shown for all grades of
    A194 nuts are for cold formed and hot forged nuts. When
    nuts are machined from bar stock the nut must be
    additionally marked with the letter ‘B’.
  3. Nuts are not required to be marked
    unless specified by the purchaser. When marked, the
    identification marking shall be the grade letter O, A or
    B.
  4. Properties shown are those of
    nonplated or noncoated coarse thread hex nuts.
  5. Properties shown are those of coarse
    thread heavy hex nuts.
  6. Properties shown are those of coarse
    thread heavy hex nuts.
  7. Properties shown are those of coarse
    8-pitch thread heavy hex nuts.
  8. Hardnesses are Brinell Hardness
    Numbers.
  9. The nut manufacturer, at his option,
    may add other markings to indicate the use of atmospheric
    corrosion resistant steel.
  10. Specifications –
  11. ASTM A563 — Carbon and Alloy Steel Nuts.

    ASTM A194/A194M — Carbon and Alloy Steel Nuts for Bolts
    for High Pressure and High Temperature Service.