ASTM A193
Although, this material is often available in national coarse (UNC) thread pitches, if being used in traditional applications, threads are specified 8 threads per inch (tpi) for diameters above one inch. Below is a basic summary of a few of the common grades. ASTM A193 covers a number of other standard specifications not covered in this description including B5, B6 and B16.
Grade:
B7 | Alloy steel, AISI 4140/4142 quenched and tempered | ||||
B8 | Class 1 Stainless steel, AISI 304, carbide solution treated. | ||||
B8M | Class 1 Stainless steel, AISI 316, carbide solution treated. | ||||
B8 | Class 2 Stainless steel, AISI 304, carbide solution treated, strain hardened | ||||
B8M | Class 2 Stainless steel, AISI 316, carbide solution treated, strain hardened |
ASTM A194
Grade:
2 | Carbon steel heavy hex nuts |
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2H | Quenched & tempered carbon steel heavy hex nuts |
2HM | Quenched & tempered carbon steel heavy hex nuts |
4 | Quenched & tempered carbon-molybdenum heavy hex nuts |
7 | Quenched & tempered alloy steel heavy hex nuts |
7M | Quenched & tempered alloy steel heavy hex nuts |
8 | Stainless AISI 304 heavy hex nuts |
8M | Stainless AISI 316 heavy hex nuts |
ASTM A307
Grade:
A | Headed bolts, threaded rods and bent bolts intended for general applications. | ||
B | Heavy hex bolts and studs intended for flanged joints in piping systems with cast iron flanges. | ||
C* | Non-headed anchor bolts, either bent or straight, intended for structural anchorage purposes. The end of a grade C anchor bolt intended to project from the concrete will be painted green for identification purposes. Permanent marking is a supplemental requirement. *As of August 2007, grade C has been replaced by specification F1554 grade 36. We will continue to supply grade C, if required by the project. |
Mechanical Properties:
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Grade | Tensile, ksi | Yield, min, ksi | Elong %, min |
A | 60 min | -- | 18 |
B | 60 - 100 | -- | 18 |
C* | 58 - 80 | 36 | 23 |
Recommended Nuts and Washer:
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Nuts | Washers | ||
A307 Grades A & C* | A307 Grade B | ||
1/4 - 1-1/2 | 1-5/8 - 4 | 01/04/04 | |
A563A Hex | A563A Heavy Hex | A563A Heavy Hex | F844 |
ASTM A320
Like the ASTM A193 specification, unless otherwise specified, the 8UN thread series is specified on fastener larger than 1” in diameter. Below is a basic summary of a few of the common grades within the ASTM A320 specification. A number of other less common grades of ASTM A320 exist, but not covered in the description below.
Grade:
L7 Alloy steel | AISI 4140/4142 Quenched and tempered |
L43 Alloy steel | AISI 4340 Quenched and tempered |
B8 Class 1 Stainless steel | AISI 304, carbide solution treated |
B8M Class 1 Stainless steel | AISI 316, carbide solution treated |
B8 Class 2 Stainless steel | AISI 304, carbide solution treated, strain hardened |
B8M Class 2 Stainless steel | AISI 316, carbide solution treated, strain hardened |
ASTM A325
This specification is applicable to heavy hex structural bolts only. For bolts of other configurations and thread lengths with similar mechanical properties, see Specification A 449. Bolts for general applications, including anchor bolts, are covered by Specification A 449. Also refer to Specification A 449 for quenched and tempered steel bolts and studs with diameters greater than 1-1/2" but with similar mechanical properties.
Type:
TYPE 1 | Medium carbon, carbon boron, or medium carbon alloy steel. |
TYPE 2 | Withdrawn November 1991 |
TYPE 3 | Weathering steel |
T | Fully threaded A325. (Restricted to 4 times the diameter in length) |
M | Metric A325 |
ASTM A354
A354 BD | A354 grade BD bolts are higher in strength than A354 grade BC and equal in strength to ASTM A490 bolts. Unlike ASTM A490 however, the A354 BD specification is unrestricted in its configuration. Since A490 bolts are heavy hex structural bolts and do not exceed 1-1/2" diameter, specification A354 BD should be considered for anchor bolts, threaded rods, other styles of headed bolts, and bolts larger than 1-1/2" diameter where similar mechanical properties are desired. A354 grade BD does not require a magnetic particle test as is required by the A490 specification. Research conducted on bolts of similar material and manufacture indicates that hydrogen-stress cracking or stress cracking corrosion may occur on hot-dip galvanized Grade BD bolts. For more information about this subject, please see our FAQ that addresses galvanizing of high strength bolts. |
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A354 BC | Lower in strength than grade BD. |
Mechanical Propertie:
Grade | Size | Tensile, ksi, min | Yield, ksi, min | Elong %, min | RA %, min |
---|---|---|---|---|---|
BC | 1/4 - 2-1/2 | 125 | 109 | 16 | 50 |
2-5/8 - 4 | 115 | 99 | 16 | 45 | |
BD | 1/4 - 2-1/2 | 150 | 130 | 14 | 40 |
2-5/8 - 4 | 140 | 115 | 14 | 40 |
Recommended Nuts and Washer:
Nuts | Washers | |||
---|---|---|---|---|
Grade BC | Grade BD | |||
Plain | Galvanized | Plain | ||
A563C Heavy Hex | A563DH Heavy Hex | A563DH Heavy Hex | F436 | |
* Nuts of other grades load stresses greater than the specified grade are suitable. Follow the link for an ASTM A563 Nut Compatibility Chart. |
ASTM A449
ASTM A449 is virtually identical in chemistry and strength to ASTM A325 and SAE J429 grade 5. However, A449 is more flexible in the sense that it covers a larger diameter range and is not restricted by a specific configuration.
Types:TYPE 1 | Plain carbon steel, carbon boron steel, alloy steel, or alloy boron steel. |
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TYPE 2 | Withdrawn 2003 |
TYPE 3 | Weathering steel |
Mechanical Properties:
Size | Tensile, ksi | Yield, ksi | Elong. %, min | RA %, min |
---|---|---|---|---|
1/4 - 1 | 120 min | 92 min | 14 | 35 |
1-1/8 - 1-1/2 | 105 min | 81 min | 14 | 35 |
1-5/8 - 3 | 90 min | 58 min | 14 | 35 |
Recommended Nuts And Washers:
Nuts | Washers | |||
---|---|---|---|---|
Plain | Galvanized | |||
1/4 - 1-1/2 | 1-5/8 - 3 | 1/4 - 3 | ||
A563B Hex | A563A Heavy Hex | A563DH Heavy Hex | F436 | |
Note: Nuts of other grades having proof load stresses greater than the specified grade are suitable. The ASTM A563 Nut Compatibility Chart has a complete list of specifications. |
ASTM A490
A490 bolts are similar in application and dimensions to A325 heavy hex structural bolts but are made from an alloy steel rather than a medium carbon steel, resulting in a higher strength fastener. The A490 specification is applicable to heavy hex structural bolts only. For bolts with different thread lengths than specified for structural bolts but with similar mechanical properties, see Specification A354 grade BD.
ASTM A490 bolts shall not be coated by hot-dip galvanizing, mechanical deposition, or electroplating with zinc or other metallic coatings due to the potential risk of hydrogen embrittlement. Additional testing in the form of Magnetic Particle Inspection for Longitudinal Discontinuities and Transverse Cracks is a requirement of the A490 specification.
Type:
TYPE 1 | Medium carbon and alloy steel. |
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TYPE 2 | Withdrawn in 2002. |
TYPE 3 | Weathering steel. |
M | Metric A490. |
Connection Types:
SC | Slip critical connection. |
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N | Bearing type connection with threads included in the shear plane. |
X | Bearing type connection with threads excluded from the shear plane. |
Mechanical Properties:
Size | Tensile, ksi | Yield, ksi | Elong. %, min | RA %, min |
---|---|---|---|---|
1/2 - 1-1/2 | 150-173 | 130 | 14 | 40 |
Nuts | Washers | |||
---|---|---|---|---|
Type 1 | Type 3 | Type 1 | Type 3 | |
A563DH | A563DH3 | F436-1 | F436-3 |
Note: Nuts conforming to A194 Grade 2H are a suitable substitute for use with A490 heavy hex structural bolts. Follow the link for an ASTM A563 Nut Compatibility Chart. The bolts shall not be coated by hot-dip zinc coating, mechanical deposition, or electroplating with zinc or other metallic coatings due to the potential for hydrogen embitterment. Read more about issues with galvanizing ASTM A490. Each sample representative of the lot shall be magnetic particle inspected for longitudinal discontinuities and transverse cracks.
ASTM A563
The ASTM A563 specification covers the chemical and mechanical requirements for carbon and alloy steel nuts used on bolts, studs, and externally threaded fasteners. The charts below address over tapping allowances for hot-dip galvanized nuts, grade marking requirements, and mechanical requirements. For information on suitable nuts for various grades of bolts, visit the Nut Compatibility Chart.
According the A563 specification, "The requirements for any grade of nut may, at the supplier's option, and with notice to the purchaser, be fulfilled by furnishing nuts of one of the stronger grades specified herein unless such a substitution is barred in the inquiry and purchase order". This is important because some nut grades are not readily available in certain sizes and finishes. Additionally, the specification allows for the substitution of ASTM A194 grade 2H nuts in lieu of A563 grade DH nuts due to the lack of availability of grade DH nuts in nominal sizes ¾" and larger.
Hot-dip galvanized nuts must be tapped oversize to allow for the added thickness of the zinc on the threads of the externally threaded fastener. These allowances are addressed in the chart below and a more detailed explanation of this issue can be found in the Frequently Asked Questions section of this site. Various nut styles exist and to some degree are determined by their grade. These styles include hex, heavy hex, square, jam, coupling and sleeve.
Scope:
- Standard specification for carbon and alloy steel nuts.
A | Low carbon steel, hex or heavy hex |
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B | Low carbon steel, hex or heavy hex |
C | Carbon steel, quenched and tempered, heavy hex |
D | Carbon steel, quenched and tempered, heavy hex |
DH | Carbon steel, quenched and tempered, heavy hex |
C3 | Weathering steel, quenched and tempered, heavy hex |
DH3 | Weathering steel, quenched and tempered, heavy hex |
Mechanical Properties:
Grade | Style | Size, in. | Proof Load, ksi | Hardness, HBN | |
---|---|---|---|---|---|
Black | Galvanized | ||||
A | Hex | 1/4 - 1-1/2 | 90 | 68 | 116 - 302 |
Heavy Hex | 1/4 - 4 | 100 | 75 | 116 - 302 | |
B | Heavy Hex | 1/4 - 1 | 133 | 100 | 121 - 302 |
Heavy Hex | 1-1/8 - 1-1/2 | 116 | 87 | 121 - 302 | |
C / C3 | Heavy Hex | 1/4 - 4 | 144 | 144 | 143 - 352 |
D | Heavy Hex | 1/4 - 4 | 150 | 150 | 248 - 352 |
DH / DH3 | Heavy Hex | 1/4 - 4 | 175 | 150 | 248 - 352 |
For UNC, 8UN, 6UN and Coarse Pitch Threads |
ASTM F1554
The bolts can be either cut or roll threaded and a weldable grade 55 can be substituted for grade 36 at the supplier’s option. Color coding on the end 36 blue, 55 yellow, and 105 red helps facilitate easy identification in the field. Permanent manufacturer and grade marking is allowed under the S2 supplementary requirements.
Applications for F1554 anchor bolts include columns in structural steel framed buildings, traffic signal and street lighting poles, and overhead highway sign structures to name just a few.