Fastener Identification Marking

Grade Identification Marking	Specifications	Material	Nominal Size	Proof Load Stress	Tensile Strength Min. ksi	Hardness Rockwell
						Min.	Max.
	SAE J429 Grade 1	Low or Medium Carbon Steel	1/4 thru 1-1/2	33	60	B70	B100
	SAE J429 Grade 2		1/4 thru 3/4 over 3/4 thru 1-1/2	55 33	74 60	B80 B70	B100 B100
	ASTM A307 – Grade A		1/4 thru 4	–	60	B69	B100
	SAE J429 – Grade 5	Medium Carbon Steel,Quenched and Tempered	1/4 thru 1 over 1 thru 1-1/2	85	120	C25	C34
	ASTM A449 – Type 1			74	105	C19	C30
	ASTM A325 – Type 1 Refer to Note 4	Medium Carbon Steel,Quenched and Tempered	1/2 thru 1 over 1 to 1-1/2	85 74	120 105	C24 C19	C35 C31
	ASTM A325 – Type 2	Low Carbon Martensite Steel, Quenched and Tempered
	ASTM A325 – Type 3 Refer to Note 5	Atmospheric Corrosion Resistant Steel,Quenched and Tempered	1/2 thru 1 over 1 to 1-1/2	85 74	120 105	C24 C19	C35 C31
	ASTM A354 -Grade BC	Medium Carbon Alloy Steel, Quenched and Tempered	1/4 thru 2-1/2 over 2-1/2 thru 4	105 95	125 115	C26 C22	C36 C33
	SAE J429 – Grade 8	Medium Carbon Alloy Steel, Quenched and Tempered	1/4 thru 1-1/2	120 120 105	150 150 140	C33 C33 C33	C39 C39 C39
	ASTM A354 – Grade BD Refer to Note 6		1/4 thru 2-1/2 over 2-1/2 thru 4
	SAE J429 – Grade B2	Low Carbon Martensite Steel, Quenched and Tempered	1/4 thru 1	120	150	C33	C39
	ASTM A490 – Type 1	Medium Carbon Alloy Steel, Quenched and Tempered	1/2 thru 1-1/2	120	150 min. 170 max.	C33	C38
	ASTM A490 – Type 2	Low Carbon Martensite Steel, Quenched and Tempered	1/2 thru 1	120	150 min. 170 max.	C33	C38
	ASTM A490 – Type 3 Refer to Note 5	Atmospheric Corrosion Resistant Steel, Quenched and Tempered	1/2 thru 1-1/2	120	150 min. 170 max.	C33	C38
	ASTM A-193 – Grade B7	4140 Alloy Steel Quenched and Tempered	1/2 to 3-1/2	105	125 min.

Notes regarding Fastener Identification Marking

1. In addition to the indicated grade marking, all grades included in this table must be marked for manufacturer identification.
2. While hex heads are shown, grade markings apply equally to products with other head configurations.
3. Hardness are Brindell Hardness numbers.
4. A325 Type 1 bolts may also be marked with 3 radial lines 120 degrees apart in addition to the A325 marking.
5. The bolt manufacturer, at his option, may add other markings to indicate the use of atmospheric corrosion resistant steel.
6. A354 Grade BD products, in sizes 1-1/2” and smaller, are identified as shown and, at the manufacturer’s option, may have the letters BD added. Larger sizes are marked only BD.
7. Specifications:
   

   ASTM 325	High strength bolts for structural steel joints
   SAE J429	Mechanical and material requirements for externally threaded fasteners
   ASTM A307	Carbon steel externally threaded standard fasteners
   ASTM A449	Quenched and tempered steel bolts and studs
   ASTM A354	Quenched and tempered alloy steel bolts, studs and other externally threaded fasteners
   ASTM A490	Heat treated steel structural bolts, 150 ksi minimum tensile strength
   ASTM A193-B7	Quenched and tempered alloy steel heavy hex bolts