Fastener Identification Markings and Bolt Strength Requirements

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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)	Min	Max
	SAE J429 Grade 1	Low or Medium Carbon Steel	¼" - 1½"	33	36	60	B70	B100
	A307 Grade A		¼" - 4"	-	-	60	B69	B100
	A307 Grade B			-	-	60 min 100 max	B69	B95
One End Green	A307 Grade C *Replaced see note 8.			-	36	58 min 80 max	-	-
One End Blue	F1554 Grade 36			-	36	58 min 80 max	-	-
One End Yellow	F1554 Grade 55			-	55	75 min 95 max	-	-
	SAE J429 Grade 2		¼" - ¾" ⅞" - 1½"	55 33	57 36	74 60	B80 B70	B100 B100
	A193/A320 Grade B8	AISI SS304 Stainless	No Restrictions	-	30	75	-	B96
	A193/A320 Grade B8M	AISI SS316 Stainless Steel
	A325 Type 1	Medium Carbon Steel, Q & T	½" - 1" 1⅛" - 1½"	85 74	92 81	120 105	C24 C19	C35 C31
	A325 Type 3	Atmospheric Corrosion Resistant Steel, Q & T
	SAE J429 Grade 5	Medium Carbon Steel, Q & T	¼" - 1" 1⅛" - 1½"	85 74	92 81	120 105	C25 C19	C34 C30
	A449 Type 1		¼" - 1" 1⅛" - 1½" 1⅝" - 3"	85 74 55	92 81 58	120 105 90	C25 C19 B91	C34 C30 B100
	A193 Grade B7	Medium Carbon Alloy Steel, Q & T	¼" - 2½" 2⅝" - 4" 4⅛" - 7"	-	105 95 75	125 115 100	-	C35 C35 C35
	A354 Grade BC		¼" - 2½" 2⅝" - 4"	105 95	109 94	125 115	C26 C22	C36 C33
One End Red	F1554 Grade 105		¼" - 3"	-	105	125 min 150 max	-	-
	A320 Grade L7	AISI 4140, 4142, or 4145	¼" - 2½"	-	105	125	-	-
	A320 Grade L43	AISI 4340	¼" - 4"	-	105	125	-	-
	A490 Type 1	Medium Carbon Alloy Steel, Q & T	½" - 1½"	120	130	150 min 173 max	C33	C38
	A490 Type 3	Atmospheric Corrosion Resistant Steel, Q & T
	SAE J429 Grade 8	Medium Carbon Alloy Steel, Q & T	¼" - 1½"	120	130	150	C33	C39
	A354 Grade BD		¼" - 2½" 2⅝" - 4"	120 105	130 115	150 140	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. Stamping of F1554 and A307 grade C bolts 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. Hex cap screws and bolts and one end of studs shall be marked "A449". In addition, fasteners shall be permitted to be marked with three radial lines 120° apart.
8. ASTM A307 grade C has been replaced by ASTM F1554 grade 36.