SAE J429

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