SAE J429
- Scope
- Grades
- Chemical Composition
- Mechanical Properties
- Proof Load
- Tensile Strength
- Bolts Grade Identification Mark
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 |
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 |
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