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ASTM A307 Technical Data

Order A307 Hex Bolts Order A307 All Thread Rod

This specification covers the chemical and mechanical requirements of two grades of carbon steel bolts and studs in sizes 1⁄4 in. through 4 in.

Technical Data: ASTM A307 Chemical Requirements for Grades A and B Bolts, Studs, and Threaded Rod ASTM A307 Hardness Requirements for Bolts, Studs, and Threaded Rods ASTM A307 Tensile Requirements for Full-Size Bolts, Studs, and Threaded Rod ASTM A307 Tensile Requirements for Machined Specimens ASTM A307 Sample Sizes and Acceptance Numbers for Inspection of Hot-Dip or Mechanically Deposited Zinc-Coated Threads

	Heat Analysis	Product Analysis
Carbon, max	0.29	0.33
Manganese, max	1.20	1.25
Phosphorus, max	0.04	0.041
Sulfur, max
Grade A	0.15	A
Grade B	0.05	0.051

Grade	Nominal Length, in.	Hardness^A
		Brinell		Rockwell B
		min	max	min	max
A	Less than 3 × dia^B	121	241	69	100
A	3 × dia and longer		241		100
B	Less than 3 × dia^B	121	212	69	95
B	3 × dia and longer		212		95

^AAs measured anywhere on the surface or through the cross section.
^BAlso bolts with drilled or undersize heads. These sizes and bolts with modified heads shall meet the minimum and maximum hardness as hardness is the only requirement.

Bolt Size, in.	Threads per inch	Stress Area, ^A in.²	Tensile Strength, lbf^B
			Grade A, min ^C	Grade B
				Grade B
				min^D	max^D
1⁄4	20	0.0318	1,900	1,900	3,180
5⁄16	18	0.0524	3,100	3,100	5,240
3⁄8	16	0.0775	4,650	4,650	7,750
7⁄16	14	0.1063	6,350	6,350	10,630
1⁄2	13	0.1419	8,500	8,500	14,190
9⁄16	12	0.182	11,000	11,000	18,200
5⁄8	11	0.226	13,550	13,550	22,600
3⁄4	10	0.334	20,050	20,050	33,400
7⁄8	9	0.462	27,700	27,700	46,200
1	8	0.606	36,350	36,350	60,600
1 1⁄8	7	0.763	45,800	45,800	76,300
1 1⁄4	7	0.969	58,150	58,150	96,900
1 3⁄8	6	1.155	69 300	69,300	115,500
1 1⁄2	6	1.405	84 300	84,300	140,500
1 3⁄4	5	1.90	114,000	114,000	190,000
2	4½	2.50	150,000	150,000	250,000
2 1⁄4	4½	3.25	195,000	195,000	325,000
2 1⁄2	4	4.00	240,000	240,000	400,000
2 3⁄4	4	4.93	295,800	295,800	493,000
3	4	5.97	358,200	358,200	597,000
3 1⁄4	4	7.10	426,000	426,000	710,000
3 1⁄2	4	8.33	499,800	499,800	833,000
3 3⁄4	4	9.66	579,600	579,600	966,000
4	4	11.08	664,800	664,800	1,108,000

^B1 lbf = 4.448 N.
^CBased on 60 ksi (414 MPa).
^DBased on 60–100 ksi (414–690 MPa).

	Grade A	Grade B
Tensile strength, ksi	60 min	60-100
Yield point, min ksi	…	…
Elongation in 2 in., min, %	18	18
Elongation in 2 in., min, %	18	18

Lot Size	Sample Size^A	Acceptance Number
2 to 90	13	1
91 to 150	20	2
151 to 280	32	3
281 to 500	50	5
501 to 1,200	80	7
1,201 to 3,200	125	10
3,201 to 10,000	200	14
10,001 and over	315	21

^AInspect all bolts in the lot if the lot size is less than the sample size.

ASTM A307 Technical Data

Chemical Requirements for Grades A and B Bolts, Studs and Threaded Rod

Hardness Requirements for Bolts, Studs, and Threaded Rod

Tensile Requirements for Full-Size Bolts, Studs, and Threaded Rod

Tensile Requirements for Machined Specimens

Sample Sizes and Acceptance Numbers for Inspection of Hot-Dip or Mechanically Deposited Zinc-Coated Threads