Fastener Identification Markings
Bolt Strength Requirements

Grade Marking	Specification	Material and Treatment	Nominal Size (In.)	Mechanical Properties					Hardness Rockwell
				Proof Load Min (ksi)	Yield Strength Min (ksi)	Tensile Strength Min (ksi)	Elong % Min [9]	RA % Min [10]	Min	Max
	SAE J429 Grade 1	Low or Medium Carbon Steel	1⁄4" - 11⁄2"	33	36	60	18	35	B70	B100
	A307 Grade A		1⁄4" - 4"	-	-	60	18	-	B69	B100
	A307 Grade B			-	-	60 min 100 max	18	-	B69	B95
One End Green	A307 Grade C [7]			-	36	58 min 80 max	23	-	-	-
One End Blue	F1554 Grade 36			-	36	58 min 80 max	23	40	-	-
One End Yellow	F1554 Grade 55		1⁄4" - 2"	-	55	75 min 95 max	21	30	-	-
			21⁄4"- 21⁄2"				21	22
			23⁄4" - 3"				21	20
			31⁄4" - 4"				21	18
	SAE J429 Grade 2 [8]		1⁄4" - 3⁄4" 7⁄8" - 11⁄2"	55 33	57 36	74 60	18 18	35	B80 B70	B100 B100
	A193/A320 Grade B8 Class 1	AISI SS304 Stainless	No Restrictions	-	30	75	30	50	-	B96
	A193/A320 Grade B8M	AISI SS316 Stainless Steel
	A325 Type 1	Medium Carbon Steel, Q & T	1⁄2" - 1" 11⁄8" - 11⁄2"	85 74	92 81	120 105	14	35	C24 C19	C35 C31
	A325 Type 3	Atmospheric Corrosion Resistant Steel, Q & T
	SAE J429 Grade 5	Medium Carbon Steel, Q & T	1⁄4" - 1" 11⁄8" - 11⁄2"	85 74	92 81	120 105	14	35	C25 C19	C34 C30
	A449 Type 1		1⁄4" - 1" 11⁄8" - 11⁄2" 15⁄8" - 3"	85 74 55	92 81 58	120 105 90	14	35	C25 C19 B91	C34 C30 B100
	A449 Type 3	Weathering Steel, Q & T	1⁄4" - 1" 11⁄8" - 11⁄2" 15⁄8" - 3"	85 74 55	92 81 58	120 105 90	14	35	C25 C19 B91	C34 C30 B100
	A193 Grade B7	Medium Carbon Alloy Steel, Q & T	1⁄4" - 21⁄2" 25⁄8" - 4" 41⁄8" - 7"	-	105 95 75	125 115 100	16 16 18	50 50 50	-	C35 C35 C35
	A354 Grade BC		1⁄4" - 21⁄2" 25⁄8" - 4"	105 95	109 94	125 115	16 16	50 45	C26 C22	C36 C33
One End Red	F1554 Grade 105		1⁄4" - 3"	-	105	125 min 150 max	15	45	-	-
	A320 Grade L7	AISI 4140, 4142, or 4145	1⁄4" - 21⁄2"	-	105	125	16	50	-	-
	A320 Grade L43	AISI 4340	1⁄4" - 4"	-	105	125	16	50	-	-
	A490 Type 1	Medium Carbon Alloy Steel, Q & T	1⁄2" - 11⁄2"	120	130	150 min 173 max	14	40	C33	C38
	A490 Type 3	Atmospheric Corrosion Resistant Steel, Q & T
	SAE J429 Grade 8	Medium Carbon Alloy Steel, Q & T	1⁄4" - 11⁄2"	120	130	150	12	35	C33	C39
	A354 Grade BD [6]		1⁄4" - 21⁄2" 25⁄8" - 4"	120 105	130 115	150 140	14	40	C33 C31	C39 C39

1. All specifications are ASTM unless otherwise noted.
2. All specifications shall be marked by the manufacturer with a unique identifier to identify the manufacturer or private label distributor, as appropriate.
3. Q & T - Quenched and Tempered.
4. Although markings are shown on hex heads, stamping is a requirement on one end of rods and studs. The exception is F1554 and A307 grade C in which stamping is a supplemental requirement while color coding is required.
5. Although markings are shown on hex heads, grade markings apply equally to products with other head configurations.
6. All Grade BD products shall be marked "BD". In addition to the "BD" marking, the product may be marked with 6 radial lines 60° apart.
7. ASTM A307 grade C has been replaced by ASTM F1554 grade 36.
8. Grade 2 requirements for diameters ranging from 1/4" through 3/4" only apply to headed fasteners up to and including 6" in length, and to studs of all lengths. For headed fasteners longer than 6", see SAE J429 grade 1.
9. Percent Elongation
10. Percent Reduction of Area