Grades - Anchor Rods

F1554 | A307 | A449 | A354 | A193 | A320 | F593 | A36* | A572*

Anchor rods can be manufactured to practically any ASTM grade with the exception of ASTM F3125 which covers several grades of structural bolts. Although anchor rods can be manufactured to a variety of grades, ASTM F1554 is the only specification that is specifically an anchor bolt.

ASTM F1554 Grades 36, 55, and 105

The F1554 specification covers anchor bolts that are designed for anchoring structural supports to concrete foundations. Anchor bolts under this grade can conform to a straight rod, forged headed anchor bolt or a bent anchor bolt configuration. There are three grades within this specification, 36, 55, or 105. The minimum yield strength (ksi) is represented in the grade number. Anchor rods (or other configurations) that meet any of the three grades are color coded at the end that will project from the concrete to easily identify the grade used in the field (Grade 36: Blue, Grade 55: Yellow, Grade 105: Red). Permanent stamping with grade symbol and manufacturer’s identifier is a supplementary requirement and is performed upon request.

F1554 Mechanical Properties

Grade	Size inches	Tensile, ksi	Yield, ksi min	Yield, MPa min	Elong. % min	RA % min
36	¹⁄₂ - 4	58 - 80	36	248	23	40
55	¹⁄₂ - 2	75 - 95	55	380	21	30
	2¹⁄₄ - 2¹⁄₂	75 - 95	55	380	21	30
	2³⁄₄ - 3	75 - 95	55	380	21	30
	3¹⁄₄ - 4	75 - 95	55	380	21	30
105	¹⁄₂ - 3	125 - 150	105	724	15	45
Stamping of F1554 bolts with manufacturer's identification is a supplemental requirement (S2) Color coding is required unless the grade is stamped in accordance with supplemental requirement (S3). When Grade 36 is specified, a weldable Grade 55 may be furnished at the supplier's option.

ASTM A307 Grades A and B

ASTM A307 Grade A

The A307 specification is manufactured from low-carbon, mild steel A36 round bar and covers most run of the mill bolts that you find in the marketplace. Common finishes include plain black, hot-dip galvanized, and zinc plated. Per the A307A specification, a permanent grade symbol and manufacturer’s identifier must be stamped on one end of the rod. The stamping requirement is often times ignored with all thread since the applications are typically non-critical and it is common for the end user to cut the rod to finished lengths in the field.

A307 Grade A Mechanical Properties

Nominal Size	Mechanical Properties					Hardness Rockwell
Nominal Size	Proof Load	Yield Str.	Tensile Str.	Elong. %	R.A. %	Min	Max
¹⁄₄" - 4"	-	-	60 ksi min	18 min	-	B69	B100

ASTM A307 Grade B

This specification covers low-carbon, mild steel fully threaded studs and heavy hex bolts intended for cast iron flanged joints in piping systems with cast iron flanges. Whereas A307 grade A does not have a maximum tensile strength requirement, A307 grade B does. Similar to grade A, common finishes include plain black, hot-dip galvanized, and zinc plated. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

A307 Grade B Mechanical Properties

Nominal Size	Mechanical Properties					Hardness Rockwell
Nominal Size	Proof Load	Yield Str.	Tensile Str.	Elong. %	R.A. %	Min	Max
¹⁄₄" - 4"	-	-	60 min 100 max	18	-	B69	B95

ASTM A449

The A449 specification is a high strength grade manufactured from a medium carbon or alloy steel. To achieve the required mechanical properties, the raw material undergoes a heat-treating process to develop its strength. Common finishes are plain black and hot-dip galvanized. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

A449 Mechanical Properties

Size	Tensile, ksi	Yield, ksi	Elong. %, min	RA %, min
¹⁄₄ - 1	120 min	92 min	14	35
1¹⁄₈ - 1¹⁄₂	105 min	81 min	14	35
1⁵⁄₈ - 3	90 min	58 min	14	35

ASTM A354 Grades BC and BD

A354 Grade BC

The A354 Grade BC specification covers quenched and tempered alloy steel headed bolts, bent anchor bolts, and anchor rods. This is a high-strength specification that does not have configuration limitations and is used for general applications. Common finishes are plain black and hot-dip galvanized. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

A354 Grade BC Mechanical Properties

Grade Marking	Nominal Size	Mechanical Properties					Hardness Rockwell
Grade Marking	Nominal Size	Proof Load	Yield Str.	Tensile Str.	Elong. %	R.A. %	Min	Max
	¹⁄₄" - 2¹⁄₂"	105	109	125	16	50	C26	C36
	2¹⁄₂"+	95	99	115	16	45	C22	C33

ASTM A354 Grade BD

The A354 Grade BD specification covers quenched and tempered medium carbon, alloy steel headed bolts, bent anchor bolts, and anchor rods. It is virtually identical to the A490 specification in chemical and mechanical properties. However, it does not have the configuration limitations that A490 has. If you have a project with A490 anchor rods specified, you should ask the Engineer of Record to consider A354 Grade BD in its place. A354 Grade BD is higher in strength than most common anchor bolt grades and is most commonly supplied as plain black finish due to it being subject to the risk of hydrogen embrittlement when plated or galvanized. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

A354 Grade BD Mechanical Properties

Grade Marking	Nominal Size	Mechanical Properties					Hardness Rockwell
Grade Marking	Nominal Size	Proof Load	Yield Str.	Tensile Str.	Elong. %	R.A. %	Min	Max
	All Sizes	-	130	150-173	14	40	C33	C38
					14	40

ASTM A193 Grades B7, B8, and B8M

A193 Grade B7

The A193 B7 specification is made from a medium-carbon, alloy steel that has been quenched and tempered to reach its higher strength. This grade is designed for high temperature or high-pressure applications and intended for use in flanges, valves, pressure vessels, and fittings. The B7 specification is not as commonly called out for anchor rod applications, except for all thread studs, which are common in the marketplace.

It is important to note that in this specification, the threading standard for rods above 1” in diameter is 8 threads per inch (tpi). B7 anchor rods with Unified National Coarse (UNC) threads are also available, so make sure to double check which thread pattern you need for your application. Common finishes are plain black, hot-dip galvanized, and zinc plated. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

A193 Grade B7 Mechanical Properties

Grade Marking	Nominal Size	Mechanical Properties					Hardness Rockwell
Grade Marking	Nominal Size	Proof Load	Yield Str.	Tensile Str.	Elong. %	R.A. %	Min	Max
	¹⁄₄" - 2¹⁄₂"	-	105	125	16	50	-	C35
	2⁵⁄₈" - 4"		95	115	16	50		C35
	4¹⁄₈" - 7"		75	100	18	50		C35

A193 Grade B8

ASTM A193 Grade B8 Class 1 fasteners are manufactured from AISI 304 stainless steel and are designed for high temperature or high-pressure applications and intended for use in flanges, valves, pressure vessels, and fittings. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

A193 Grade B8 Class 2 bolts are strain hardened to achieve increased strength characteristics and reduce the potential for galling. Class 2 bolts are marked “B8SH” with the grade symbol underlined.

A193 Grade B8 Mechanical Properties

Grade	Size	Tensile ksi, min	Yield, ksi, min	Elong, %, min	RA % min	HBW	HRC
B8 Class 1	All	75	30	30	50	223 max	96 max
B8 Class 2	Up to 3/4	125	100	12	35	321 max	35 max
	7/8 - 1	115	80	15	35
	1-1/8 - 1-1/4	105	65	20	35
	1-3/8 - 1-1/2	100	50	28	45

A193 Grade B8M

ASTM A193 Grade B8M Class 1 fasteners are manufactured from AISI 316 stainless steel and are also designed for high temperature or high-pressure applications and intended for use in flanges, valves, pressure vessels, and fittings. Type 316 stainless offers superior corrosion resistance to type 304 stainless due to the added molybdenum. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

A193 Grade B8M Class 2 bolts are strain hardened to achieve increased strength characteristics and reduce the potential for galling. Class 2 bolts are marked “B8MSH” with the grade symbol underlined.

A193 Grade B8M Mechanical Properties

Grade	Size	Tensile ksi, min	Yield, ksi, min	Elong, %, min	RA % min	HBW	HRC
B8M Class 1	All	75	30	30	50	223 max	96 (HRB) max
B8M Class 2	Up to 3/4	110	95	15	45	321 max	35 max
	7/8 - 1	100	80	20	45
	1-1/8 - 1-1/4	95	65	25	45
	1-3/8 - 1-1/2	90	50	30	45

ASTM A320 Grades L7, L43, B8, and B8M

A320 Grade L7, and L43

The ASTM A320 L7 and L43 specifications cover alloy steel bolting materials for low-temperature service. This standard covers rolled, forged, or strain hardened bars, bolts, screws, studs, and stud bolts used for pressure vessels, valves, flanges, and fittings. However, in low-temperature environments, A320 is sometimes used for anchor rods. Similar to ASTM A193, the threading standard for rods above 1” in diameter is 8 threads per inch (tpi). L7 and L43 anchor rods with Unified National Coarse (UNC) threads are also available, so make sure to double check which thread pattern you need for your application. Common finishes are plain black, hot-dip galvanized, and zinc plated. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

The mechanical and chemical makeup of both A320 Grades L7 and L43, are virtually identical. The main difference is that the raw material used to make A320 L7 fasteners is typically 4140, whereas the raw material used to make A320 L43 is 4340. A320 L7 fasteners can be manufactured in diameters 2-1/2” and below with relative ease. However, once you get into diameters above 2-1/2”, you will often see A320 L43 specified. The reason for this is mainly due to material availability, but it is also due to the raw material 4340 being more successful in the heat treating process. The A320 L7 and L43 specifications require a Charpy Impact test, which becomes more difficult to pass for A320 L7 but is not as difficult with A320 L43 material. Because of this, engineers will often specify A320 L43 over A320 L7.

A320 Grade B8

ASTM A320 Grade B8 Class 1 fasteners are manufactured from AISI 304 stainless steel and are designed for low-temperature applications and intended for use in flanges, valves, pressure vessels, and fittings. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

A320 Grade B8 Class 2 bolts are strain hardened to achieve increased strength characteristics and reduce the potential for galling. Class 2 bolts are marked “B8SH” with the grade symbol underlined.

A320 Grade B8 Mechanical Properties

Grade	Size	Tensile ksi, min	Yield, ksi, min	Elong, %, min	RA % min	HBW	HRC
B8 Class 1	All	75	30	30	50	223 max	96 max
B8 Class 2	Up to 3/4	125	100	12	35	321 max	35 max
	7/8 - 1	115	80	15	35
	1-1/8 - 1-1/4	105	65	20	35
	1-3/8 - 1-1/2	100	50	28	45

A320 Grade B8M

ASTM A320 Grade B8M Class 1 fasteners are manufactured from AISI 316 stainless steel and are also designed for low-temperature applications and intended for use in flanges, valves, pressure vessels, and fittings. Type 316 stainless offers superior corrosion resistance to type 304 stainless due to the added molybdenum. One end of each rod requires a permanent grade symbol and manufacturer’s identifier.

A320 Grade B8M Class 2 bolts are strain hardened to achieve increased strength characteristics and reduce the potential for galling. Class 2 bolts are marked “B8MSH” with the grade symbol underlined.

A320 Grade B8M Mechanical Properties

Grade	Size	Tensile ksi, min	Yield, ksi, min	Elong, %, min	RA % min	HBW	HRC
B8M Class 1	All	75	30	30	50	223 max	96 max
B8M Class 2	Up to 3/4	110	95	15	45	321 max	35 max
	7/8 - 1	100	80	20	45
	1-1/8 - 1-1/4	95	65	25	45
	1-3/8 - 1-1/2	90	50	30	45

ASTM F593

ASTM F593 covers the chemical and mechanical requirements for stainless steel bolts, hex cap screws, and studs in diameters ranging from 1/4″ to 1-1/2″ inclusive. These fasteners are for general purpose usage and are available in seven alloy groups. Below is a basic summary of the common grades within the ASTM F593 specification. A number of other less common grades of ASTM F593 exist but are not detailed in the description below. The Mechanical Table here is limited to Alloy groups 1 and 2, as those are the most common, and the Chemical Table only shows the most common steel grades used for their respective alloy groups.

F593 Alloy Groups

Alloy Group	Alloy Designation	Alloy Type
1	303, 304, 304L, 305, 384, XM1, 18-9LW, 302HQ, 303Se	Austenitic
2	316, 316L	Austenitic
3	321, 347	Austenitic
4	430, 430F	Ferritic
5	410, 416, 416Se	Martensitic
6	431	Martensitic
7	630 (17-4)	Precipitation Hardening
*The selection of an alloy within each group is at the discretion of the manufacturer unless the purchaser requests a specific alloy.

F593 Mechanical Properties / Condition

Alloy Group	Condition	Marking	Diameter Range	Tensile, ksi	Yield, ksi min	Rockwell Hardness
1	AF	F593A	1/4 to 1-1/2	65 to 85	20	B85 max
	A	F593B	1/4 to 1-1/2	75 to 100	30	B65 to 95
	CW1	F593C	1/4 to 5/8	100 to 150	65	B95 to C32
	CW2	F593D	3/4 to 1-1/2	85 to 140	45	B80 to C32
2	AF	F593E	1/4 to 1-1/2	65 to 85	20	B85 max
	A	F593F	1/4 to 1-1/2	75 to 100	30	B65 to 95
	CW1	F593G	1/4 to 5/8	100 to 150	65	B95 to C32
	CW2	F593H	3/4 to 1-1/2	85 to 140	45	B80 to C32

ASTM A36

ASTM A36 is a steel grade, not a fastener specification. Technically anchor rods made from A36 steel should be ordered to a fastener specification such as F1554 Grade 36, A307 Grade A, A307 or Grade B. The appropriate fastener specification will depend on the application. Some companies stock all thread rod manufactured from A36 steel and can certify it as such upon request.

A36 Mechanical Requirements

Tensile, ksi	58 - 80
Yield, min ksi	36
Elongation, min % in 2”	20
Elongation, min % in 8”	23
This abridged table shows only the mechanical requirements for bars. The complete table can be found in the ASTM standard at www.astm.org

A36 Chemical Requirements

Thickness, inches	Up to 3/4"	Over 3/4" to 1-1/2"	Over 1-1/2" to 4"	Over 4"
Carbon, max %	0.26	0.27	0.28	0.29
Manganese, %		0.60 - 0.90	0.60 - 0.90	0.60 - 0.90
Phosphorous, max %	0.04	0.04	0.04	0.04
Sulfur, max %	0.05	0.05	0.05	0.05
Silicon, max %	0.40	0.40	0.40	0.40
Copper, min % when copper is specified	0.20	0.20	0.20	0.20
This abridged table shows only the chemical requirements for bars. The complete table including shapes and plates can be found in the ASTM standard at www.astm.org

ASTM A572

A572 Grade 50 covers structural steel shapes, plates, and bars. Although this grade does not specifically cover anchor rods, engineers speicify it on plans on a regular basis. Normally a weldable F1554 Grade 55 would be substituted, however an anchor rod can be certified to A572 Grade 50 as long as the manufacturer and end user agree upon the required configuration, type of or amount of threads, style of head (when required), and the compatible nut or washer.

A572 Grade 50 Mechanical Requirements

Grade	Yield, min ksi	Tensile, min ksi	Elongation, min % in 8”	Elongation, min % in 2”
50	50	65	18	21

A572 Grade 50 Chemical Requirements

Grade	Maximum Diameter, inches	Carbon, max%	Manganese, max%	Phosphorus, max%	Sulfur, max%	Silicon, max%
50	4	0.23	1.35	0.04	0.05	0.40