SAE J429 standard
covers specifications to chemical, mechanical and other material requirements
for inch-series carbon and alloy steel bolts, screws, studs, and U-bolts, used
in automotive and related industries in sizes up-to 1-1/2 inch, inclusive.
SAE J429 Grades
Grade
Designation
Products
Nominal
Size Range Dia, Inch
1
Bolts,
Screws, Studs
1/4 through
1-1/2
2
Bolts,
Screws, Studs
1/4 through
1-1/2
3/4 through
1-1/2
4
Studs
1/4 through
1-1/2
5
Bolts,
Screws, Studs
1/4 through
1
Over 1
through 1-1/2
5.2
Bolts,
Screws
1/4 through
1
8
Bolts,
Screws, Studs
1/4 through
1-1/2
8.1
Studs
1/4 through
1-1/2
8.2
Bolts,
Screws, Studs
1/4 through
1
SAE J429 Chemical
Composition
Grade
Nominal
Size, Dia, Inch.
Material
C %
Mn %
P %
S %
B %
1
1/4 through
1-1/2
Low or
medium carbon steel
0.55 max
¡
0.025 max
0.025 max
¡
2
1/4 through
1-1/2
Low or
medium carbon steel
0.15 ¨C 0.55
¡
0.025 max
0.025 max
¡
4
1/4 through
1-1/2
Medium
carbon steel
0.28 ¨C 0.55
¡
0.025 max
0.13 max
¡
5
1/4 through
1-1/2
Medium
carbon steel
0.28 ¨C 0.55
¡
0.025 max
0.025 max
(4)
¡
Carbon
steel with additives (e.g. Boron or Cr or Mn)
0.15 ¨C 0.40
¡
0.025 max
0.025 max
(4)
0.0005 ¨C
0.003
5.2
1/4 through
1
Low or
medium carbon steel
0.15 ¨C 0.25
0.74 max
0.025 max
0.025 max
0.0005 ¨C
0.003
8
1/4 through
1-1/2
Medium
carbon steel Or
0.25 ¨C 0.55
¡
0.025 max
0.025 max
(4)
¡
Alloy
(6,7,8) Steel with additives (e.g. Boron or Cr or Mn)
0.20 ¨C 0.55
¡
0.025 max
0.025 max
(4)
¡
Medium
carbon (6,7,8) Alloy Steel
0.28 ¨C 0.55
¡
0.025 max
0.025 max
¡
8.1
1/4 through
1-1/2
Medium
carbon alloy (6,7,8) or SAE 1541 steel
0.28 ¨C 0.55
¡
0.025 max
0.04 max
¡
8.2
1/4 through
1
Low carbon
boron steel (6)
0.15 ¨C 0.25
0.74
max
0.025 max
0.025 max
0.0005 ¨C
0.003
NOTES :
1. All values are for product analysis (percent by weight). For cast or heat
analysis, use standard permissible varia-tions as shown in SAE J409.
2. For studs only, sulfur content may be 0.33% maximum.
3. For Grades 5 and 5.1, fasteners, medium carbon boron or medium carbon alloy
steels, as specified for Grade 8 fasteners, may also be used at the
manufacturer's option.
4. For studs only, sulfur content may be 0.13% maximum.
5. Grade 5 material heat treated before assembly with a hardened washer is an
acceptable substitute.
6. When the carbon content in boron steel is less than 0.25% the minimum
manganese shall be 0.60% for Grades 5, 5.1, and 5.2 and 0.70% for Grades 8, 8.1,
and 8.2.
7. Alloy steel shall contain at least one of the following elements in the
minimum quantity given: chromium 0.30%, nickel 0.30%, molybdenum 0.20%, vanadium
0.10%, manganese 1.65%. Where elements are specified in combi-nations of two,
three, four, or five and have alloy contents less than those given above, the
limit value to be applied for steel class determination is 70% of the sum of the
individual limit values shown above for the two, three, four or five elements
concerned.
8. When alloy steels are in the "as quenched" condition, prior to tempering, the
microstructure in the core of the threaded section shall be approximately 90%
martensite (refer to Table 3).
9. When boron is added the limits shall be 0.0005% to 0.003%.
SAE J429 Mechanical
Requirements for Bolts, Screws and Studs
Grade
Desig- nation
Prod ucts
Nominal
Size Dia, In
Full
Size's Bolts, Screws, Studs, Sems, Proof Load (Stress), psi
Machine
Test Specimens of Bolts, Screws, and Studs Yield's Strength (Stress)
Min, psi
Machine
Test Specimens of Bolts, Screws, and Studs Tensile Strength (Stress)
Min, psi
Machine
Test Specimens of Bolts, Screws, and Studs Elongation Min, %
Machine
Test Specimens of Bolts, Screws, and Studs Reduction of Area Min, %
Surface
Hardness Rockwell 30N Max
Core
Hardness Rockwell Min
Core
Hardness Rockwell Max
1
Bolts,
Screws. Studs
1/4 thru
1-1/2
33,0000)
60,000
36,000
60,000
18
35
¡¡
B70
B100
2
Bolts,
Screws, Studs
1/4 thru
3/40)
55,0000)
74,000
57,000
74,000
18
35
-
680
B100
Over 3/4
thru 1-1/2
33,000
60,000
36,000
60,000
18
35
-
B70
B100
4
Studs
114 thru
1-1/2
65,000
1,15,000
1,00,000
1,15,000
10
35
-
C22
C32
5
Bolts,
Screws, Studs
1/4 thru 1
85,000
1,20,000
92,000
1,20,000
14
35
54
C25
C34
Over 1 thru
1-1/2
74,000
1,05,000
81,000
1,05,000
14
35
50
C19
C30
5.1
SEMS
No. 4 thru
5/8
85,000
1,20,000
-
-
-
-
60.
C25
C40
5.2
Bolts,
Screws
1/4 thru 1
85,000
1,20,000
92,000
1,20,000
14
35
56
C26
¡¡
8
Bolts,
Screws, Studs
1/4 1/2 ru
th 1-
1,20,000
1,50,000
1,30,000
1,50,000
12
35
59.
33
39
8.1
Studs
1/4 thru
1-1/2
1,20,000
1,50,000
1,30,000
1,50,000
10
35
59.
C33
C39
8.2
Bolts,
Screws
1/4 thru 1
1,20,000
1,50,000
1,30,000
1,50,000
10
35
59.
C33
C39
Note:
1. See footnote 2 of
the Scope.
2. Yield strength is stress at which a permanent set of 0.2% of gage length
occurs.
3. Not applicable to studs or slotted and cross recess head products.
4. Proof load test. Requirements in these grades only apply to stress relieved
products.
5. Grade 2 requirements for sizes 1/4 through 3/4 in. apply only to bolts and
screws 6 in. and shorter in lengths. For bolts and screws longer than 6 in.,
Grade 1 requirements shall apply.
6. Grade 5 material heat treatment before assembly with a hardened washer is an
acceptable substitute.
7. "Full Size" means a tension test specimen consisting of a completed fastener
for testing in the ready alteration.
SAE J429 Proof Load
for Bolts, Screws and Studs
Nominal
Dia of Product and Threads per in.
Stress
Area, in2
Grade 1
Grade 2
Grade 4
Grade 5 &
5.2(2)
Grade 5.1
Grade
8,8.1, 8.2(2)
Proof
Load, lb
Proof
Load, lb
Proof
Load, lb
Proof
Load, lb
Proof
Load, lb
Proof
Load, lb
Coarse
Thread Series UNC
No. 6-32
0.00909
-
-
-
-
750
-
8-32
0.0140
-
-
-
-
1,200
-
10-24
0.0175
-
-
-
-
1,500
-
12-24
0.0242
-
-
-
-
2,050
-
1/4-20
0.0318
1,050
1,750
2,050
2,700
2,700
3,800
5/16-18
0.0524
1,750
2,900
3,400
4,450
4,450
6,300
3/8-16
0.0775
2,550
4,250
5,050
6,600
6,600
9,300
7/16-14
0.1063
3,500
5,850
6,900
9,050
9,050
12,800
1/2-13
0.1419
4,700
7,800
9,200
12,100
12,100
17,000
9/16-12
5/8-11
3/4-10
7/8-9
1-8
0.182
0.226
0.334
0.462
0.606
6,000
7,450
11,000
15,200
20,000
10,000
12,400
18,400
15,200
20,000
11,800
14,700
21,700
30,000
39,400
15,500
19,200
28,400
39,300
51,500
15,500
19,200
-
-
-
21,800
27,100
40,100
55,400
72,700
1-1/8-7
1-1/4-7
1-3/8-6
1-1/2-6
0.763
0.969
1.155
1,405
25,200
32,000
38,100
46,400
25,200
32,000
38,100
46,400
49,600
63,000
75,100
91,300
56,500
71,700
85,500
104,000
-
-
-
-
91,600
116,300
138,600
168,600
Thread
No. 6-40
0.01015
-
-
-
-
850
-
8-36
0.01474
-
-
-
-
1,250
-
10-32
0.0200
-
-
-
-
1,700
-
12-28
0.0258
-
-
-
-
2,200
-
1/4-28
0.0364
1,200
2,000
2,350
3,100
3,100
4,350
5/16-24
0.0580
1,900
3,200
3,750
4,900
4,900
6,950
3/8-24
0.0878
2,900
4,800
5,700
7,450
7,450
10,500
7/16-20
1/2-20
0.1187
0.1599
3,900
5,300
6,550
8,800
7,700
10,400
10,100
13,600
10,100
13,600
14,200
19,200
9/16-18
5/8-18
3/4-16
7/8-14
1-12
0.203
0.256
0.373
0.509
0.663
6,700
8,450
12,300
16,800
21,900
11,200
14,100
20,500
16,800
21,900
13,200
16,600
24,200
33,100
43,100
17,300
21,800
31,700
43,300
56,400
17,300
21,800
-
-
-
24,400
30,700
44,800
61,100
79,600
1 14 UNS
0.679
22,400
22,400
44,100
57,700
-
81,500
1-1/8-12
0.856
28,200
28,200
55,600
63.300
-
102,700
1-1/4-12
1,073
35,400
35,400
69,700
79,400
-
128,800
1-3/8-12
1,315
43,400
43,400
85,500
97,300
-
157,800
1-1/2-12
1,581
52,200
52,200
102,800
117,000
-
189,700
Note:
1. Proof loads and
tensile strengths are computed by multiplying the proof load stresses and
tensile strength stresses given in Table 1 by the stress area of the thread. The
stress area of sizes and thread series not included in Table 5 may be computed
from the formula: As = 0.7854 [D - (0.9743/n)]2 where D equals nominal diameter
in inches and n equals threads per inch.
2. Grades 5.2 and 8.2 applicable to sizes 1/4 through 1 in.
SAE J429 Tensile
Strength for Bolts, Screws and Studs