SAE J429

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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 – 0.55 0.025 max 0.025 max
4 1/4 through 1-1/2 Medium carbon steel 0.28 – 0.55 0.025 max 0.13 max
5 1/4 through 1-1/2 Medium carbon steel 0.28 – 0.55 0.025 max 0.025 max (4)
Carbon steel with additives (e.g. Boron or Cr or Mn) 0.15 – 0.40 0.025 max 0.025 max (4) 0.0005 – 0.003
5.2 1/4 through 1 Low or medium carbon steel 0.15 – 0.25 0.74 max 0.025 max 0.025 max 0.0005 – 0.003
8 1/4 through 1-1/2 Medium carbon steel Or 0.25 – 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 – 0.55 0.025 max 0.025 max (4)
Medium carbon (6,7,8) Alloy Steel 0.28 – 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 – 0.55 0.025 max 0.04 max
8.2 1/4 through 1 Low carbon boron steel (6) 0.15 – 0.25 0.74  max 0.025 max 0.025 max 0.0005 – 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 Full Size's Bolts, Screws, Studs, Sems, Tensile Strength (Stress) , Min, Ps' 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

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)
Tensile Strength Min, lb Tensile Strength Min. lb Tensile Strength Min, lb Tensile Strength Min, lb Tensile Strength Min, lb Tensile Strength Min, lb
Coarse Thread Series UNC
No. 6-32 0.00909 - - - - 1,100 -
8-32 0.0140 - - - - 1,700 -
10-24 0.0175 - - - - 2,100 -
12-24 0.0242 - - - - 2,900 -
1/4-20 0.0318 1,900 2,350 3,650 3,800 3,800 4,750
5/16-18 0.0524 3,150 3,900 6,000 6,300 6,300 7,850
3/8-16 0.0775 4,650 5,750 8,400 9,300 9,300 11,600
7/16-14 0.1063 6,400 7,850 12,200 12,800 12,800 15,900
1/2-13 0.1419 8,500 10,500 18,300 17,000 17,000 21,300
9/16-12
5/8-11
3/4-10
7/8-9
1-8
0.182
0.226
0.334
0.462
0.606
10,900
13,600
20,000
27,700
36,400
13,500
16,700
24,700
27,700
36,400
20,900
25,400
38,400
53,100
69,700
21,800
27,100
40,100
55,400
72,700
21,800
27,100
-
-
-
27,300
33,900
50,100
69,300
90,900
1-1/8-7
1-1/4-7
1-3/8-6
1-1/2-6
0.763
0.969
1.155
1,405
45,800
58,100
69,300
84,300
45,800
58,100
69,300
84,300
87,700
111,400
132,800
161,600
80,100
101,700
121,300
147,500
-
-
-
-
114,400
145,400
173,200
210,800
Fine Thread Series UNF
No. 6-40 0.01015 - - - - 1,200 -
8-36 0.01474 - - - - 1,750 -
10-32 0.0200 - - - - 2,400 -
12-28 0.0258 - - - - 3,100 -
1/4-28 0.0364 2,200 2,700 4,200 4,350 4,350 5,450
5/16-24 0.0580 3,500 4,300 6,700 6,950 6,950 8,700
3/8-24 0.0878 5,250 6,500 10,100 10,500 10,500 13,200
7/16-20
1/2-20
0.1187
0.1599
7,100
9,600
8,800
11,800
13,650
18,400
14,200
19,200
14,200
19,200
17,800
24,000
9/16-18
5/8-18
3/4-16
7/8-14
1-12
0.203
0.256
0.373
0.509
0.663
12,200
15,400
22,400
30,500
39,800
15,000
18,900
27,600
30,500
39,800
23,300
29,400
42,900
58,500
76,200
24,400
30,700
44,800
61,100
79,600
24,400
30,700
-
-
-
30,400
38,400
56,000
76,400
99,400
1 14 UNS 0.679 40,700 40,700 78,100 81,500 - 101,900
1-1/8-12 0.856 51,400 51,400 98,400 89,900 - 128,400
1-1/4-12 1,073 64,400 64,400 123,400 112,700 - 161,000
1-3/8-12 1,315 78,900 78,900 151,200 138,100 - 197,200
1-1/2-12 1,581 94,900 94,900 181,800 166,000 - 237,200

SAE J429 Bolts Grade Identification Mark

Grade Identification Mark
1 None
2 None
None
4 None
5
5.2
8
8.1 None
8.2

Reference Documents


  • SAE J403
  • SAE J404
  • SAE J1268
  • ASTM F2328
  • ASTM F606
  • ASTM F1470
  • ASME B18.18.2
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