SPECIFICATION FOR CARBON STEEL BOLTS AND STUDS, 60 000 PSI TENSILE STRENGTH
(Identical with ASTM Specification A307-10 except for the deletion of "private label distributor" and "as appropriate" in para. [3.1.1.])
1. Scope
1.1 This specification covers the chemical and mechanical requirements of three grades of carbon steel bolts and studs in sizes 1/4 in. through 4 in. The fasteners are designated by "Grade" denoting tensile strength and intended use, as follows:
| Grade | Description |
|---|---|
| Grade A | Bolts and studs having a minimum tensile strength of 60 ksi and intended for general applications. |
| Grade B/C | Bolts and studs having a tensile strength of 60 to 100 ksi and intended for flanged joints in piping systems with cast iron flanges, and replaced by Specification F1554 Gr.36. |
1.1.1 The term studs includes stud stock, sometimes referred to as threaded rod.
1.2 This specification does not cover requirements for machine screws, thread cutting/forming screws, mechanical expansion anchors or similar externally threaded fasteners.
1.3 Suitable nuts are covered in Specification A563. Unless otherwise specified, the grade and style of nut for each grade of fastener, of all surface finishes, shall be as follows:
| Fastener Grade and Size | Nut Grade and StyleA |
|---|---|
| A 1/4 to 1/2 in. | A, hex |
| A over 1/2 to 1-1/4 in. | A, heavy hex |
| B, 1/4 to 1-1/2 in. | A, heavy hex |
| A Nuts of other grades and styles having specified proof load stresses (Specification A563, Table 3) greater than the specified grade and style of nut are also suitable. | |
1.4 The values stated in inch-pound units are to be regarded as the standard.
1.5 Supplementary Requirement S1 of an optional nature is provided, which describes additional restrictions to be applied when bolts are to be welded. It shall apply only when specified in the inquiry, order, and contract.
1.6 Terms used in this specification are defined in Terminology F1789 unless otherwise defined herein.
2. Referenced Documents
2.1 ASTM Standards:
- A563 Specification for Carbon and Alloy Steel Nuts
- A706/A706M Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete Reinforcement
- A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
- B695 Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel
- D3951 Practice for Commercial Packaging
- F606 Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
- F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
- F1554 Specification for Anchor Bolts, Steel, 36, 55, and 105-ksi Yield Strength
- F1789 Terminology for F16 Mechanical Fasteners
- F2329 Specification for Zinc Coating, Hot-Dip, Requirements for Application to Carbon and Alloy Steel Bolts, Screws, Washers, Nuts, and Special Threaded Fasteners
2.2 ASME Standards:
- B 1.1 Unified Screw Threads
- B 18.2.1 Square and Hex Bolts and Screws
- B 18.24 Part Identifying Number (PIN) Code System
2.3 SAE Standard:
- J429 Mechanical and Material Requirements For Externally Threaded Fasteners
3. Ordering Information
3.1 Orders for externally threaded fasteners (including nuts and accessories) under this specification shall include the following:
- ASTM designation and year of issue.
- Name of product, bolts or studs; and bolt head style, that is, hex or heavy hex.
- Grade, that is, A, or B. If no grade is specified, Grade A is furnished.
- Quantities (number of pieces by size including nuts),
- Fastener size and length,
- Washers—Quantity and size (separate from bolts),
- Zinc Coating—Specify the zinc-coating process required, for example, hot-dip, mechanically deposited, or no preference (see 4.5).
- Other Finishes—Specify other protective finish, if required.
- Specify if inspection at point of manufacture is required,
- Specify if certified test report is required (see 8.2), and
- Specify additional testing (8.3) or special requirements.
- For establishment of a part identifying system, see ASME B18.24.
4. Materials and Manufacture
4.1 Steel for bolts and studs shall be made by the open-hearth, basic-oxygen, or electric-furnace process.
4.2 Bolts shall be produced by hot or cold forging of the heads or machining from bar stock.
4.3 Heat Treatment:
4.3.1 Cold headed fasteners with head configurations other than hex having a minimum head height less than or equal to 0.5 D (D is nominal diameter) shall be stress relief annealed at a minimum temperature of 875°F.
4.3.2 Stress relieving of hex head fasteners and those with minimum head heights greater than 0.5 D shall be at the manufacturer's option.
4.4 Bolt and stud threads shall be rolled or cut.
4.5 Zinc Coatings, Hot-Dip and Mechanically Deposited:
4.5.1 When zinc-coated fasteners are required, the purchaser shall specify the zinc-coating process, for example hot dip, mechanically deposited, or no preference.
4.5.2 When hot-dip is specified, the fasteners shall be zinc-coated by the hot-dip process in accordance with the requirements of Specification F2329.
4.5.3 When mechanically deposited is specified, the fasteners shall be zinc-coated by the mechanical-deposition process in accordance with the requirements of Class 55 of Specification B695.
4.5.4 When no preference is specified, the supplier may furnish either a hot-dip zinc coating in accordance with Specification F2329, or a mechanically deposited zinc coating in accordance with Specification B695, Class 55. Threaded components (bolts and nuts) shall be coated by the same zinc-coating process and the supplier's option is limited to one process per item with no mixed processes in a lot.
5. Chemical Composition
5.1 Grade A and B bolts and studs shall have a heat analysis conforming to the requirements specified in Table 1 based on the steel producer's heat analysis.
5.2 The purchaser shall have the option of conducting product analyses on finished bolts in each lot, which shall conform to the product analysis specified in Table 1.
5.3 In case of conflict or for referee purposes, the product analysis shall take precedence.
5.4 Bolts and studs are customarily furnished from stock, in which case individual heats of steel cannot be identified.
5.5 Application of heats of steel to which bismuth, selenium, tellurium, or lead has been intentionally added shall not be permitted for Grade B bolts and studs.
5.6 Chemical analyses shall be performed in accordance with Test Methods, Practices, and Terminology A751.
| Heat Analysis | Product Analysis | |
|---|---|---|
| Carbon, max | 0.29 | 0.33 |
| Manganese, max | 1.20 | 1.25 |
| Phosphorus, max | 0.04 | 0.041 |
| Sulfur, max Grade A Grade B |
0.15 0.05 |
A 0.051 |
| A Resulfurized steel is not subject to rejection based on product analysis for sulfur. | ||
6. Mechanical Properties
6.1 Grades A and B bolts and studs shall conform to the hardness specified in Table 2.
| Grade | Length, in. | HardnessA | Rockwell B | ||
|---|---|---|---|---|---|
| Brinell min | max | min | max | ||
| A | Less than 3 x diaB | 121 | 241 | 69 | 100 |
| 3 x dia and longer | ... | 241 | ... | 100 | |
| B | Less than 3 x diaB | 121 | 212 | 69 | 95 |
| 3 x dia and longer | ... | 212 | ... | 95 | |
|
A As measured anywhere on the surface or through the cross section. B Also bolts with drilled or under-size heads. These sizes and bolts with modified heads shall meet the minimum and maximum hardness as hardness is the only requirement. |
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6.2 Grade A and B bolts and studs 1-1/2 in. in diameter or less, other than those excepted in 6.4, shall be tested full size and shall conform to the requirements for tensile strength specified in Table 3.
6.3 Grade A and B bolts and studs larger than 1-1/2 in. in diameter, other than those excepted in 6.4, shall preferably be tested full size and when equipment of sufficient capacity is available and shall conform to the requirements for tensile strength specified in Table 3. When equipment of sufficient capacity for full-size bolt testing is not available, or when the length of the bolt makes full-size testing impractical, machined specimens shall be tested and shall conform to the requirements specified in Table 4.
| Bolt Size, in. | Threads per inch | Stress Area, As, in.2 | Tensile Strength, lbfB | |
|---|---|---|---|---|
| Grade A, minC | Grade B minC - maxD |
|||
| 1/4 | 20 | 0.0318 | 1,900 | 3,180 |
| 5/16 | 18 | 0.0524 | 3,100 | 5,240 |
| 3/8 | 16 | 0.0775 | 4,650 | 7,750 |
| 7/16 | 14 | 0.1063 | 6,350 | 10,630 |
| 1/2 | 13 | 0.1419 | 8,500 | 14,190 |
| 9/16 | 12 | 0.182 | 11,000 | 18,200 |
| 5/8 | 11 | 0.226 | 13,550 | 22,600 |
| 3/4 | 10 | 0.334 | 20,050 | 33,400 |
| 7/8 | 9 | 0.462 | 27,700 | 46,200 |
| 1 | 8 | 0.606 | 36,350 | 60,600 |
| 1 1/8 | 7 | 0.763 | 45,800 | 75,300 |
| 1 1/4 | 7 | 0.969 | 58,150 | 96,900 |
| 1 3/8 | 6 | 1.155 | 69,300 | 115,500 |
| 1 1/2 | 6 | 1.405 | 84,300 | 140,500 |
| 1 3/4 | 5 | 1.90 | 114,000 | 190,000 |
| 2 | 4 1/2 | 2.50 | 150,000 | 250,000 |
| 2 1/4 | 4 1/2 | 3.25 | 195,000 | 325,000 |
| 2 1/2 | 4 | 4.00 | 240,000 | 400,000 |
| 2 3/4 | 4 | 4.93 | 295,800 | 495,000 |
| 3 | 4 | 5.97 | 356,200 | 595,000 |
| 3 1/4 | 4 | 7.10 | 426,000 | 720,000 |
| 3 1/2 | 4 | 8.33 | 499,800 | 830,000 |
| 3 3/4 | 4 | 9.66 | 579,600 | 959,000 |
| 4 | 4 | 11.08 | 664,500 | 1,108,000 |
|
A Area calculated from the equation: As = 0.7854 [D - (0.9743/n)]2 where: As = stress area, D = nominal diameter of bolt, and n = threads per inch. B 1 lbf = 4.448 N. C Based on 60 ksi (414 MPa). D Based on 60-100 ksi (414-690 MPa). |
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6.4 Grades A and B bolts and studs less than three diameters in length or bolts with drilled or under-size heads are not subject to tensile tests.
6.5 In the event that bolts are tested by both full size and by machine test specimen methods, the full-size test shall govern if a controversy between the two methods exists.
6.6 For bolts and studs on which both hardness and tension tests are performed, acceptance based on tensile requirements shall take precedence in the event that there is controversy over low readings of hardness tests.
| Grade A | Grade B | |
|---|---|---|
| Tensile strength, min ksi | 60 | 60 |
| Yield point, min ksi | ... | ... |
| Elongation in 2 in., min % | 18 | 18 |
7. Threads and Dimensions
7.1 Unless otherwise specified, threads shall be the Coarse Thread Series as specified in the latest issue of ASME B1.1, and shall have a Class 2A tolerance.
7.2 Unless otherwise specified, Grade A bolts shall be hex bolts with dimensions as given in the latest issue of ASME B18.2.1. Unless otherwise specified, Grade B bolts shall be heavy hex bolts with dimensions as given in the latest issue of ASME B18.2.1.
7.3 Unless otherwise specified, bolts and studs to be used with nuts or tapped holes which have been tapped oversize, in accordance with Specification A563, shall have Class 2A threads before hot-dip or mechanically deposited zinc coating. After zinc coating the maximum limit of pitch and major diameter shall not exceed the Class 2A maximum limit by more than the following amounts:
| Diameter, in. | Oversize Limit, in. (mm)A |
|---|---|
| 1/4 | 0.016 |
| 5/16, 3/8 | 0.017 |
| 7/16, 1/2 | 0.020 |
| 9/16 to 3/4, incl | 0.022 |
| 7/8 | 0.024 |
| 1.0 to 1 1/4, incl | 0.027 |
| 1 3/8 to 4.0, incl | 0.050 |
| A These values are the same as the overlapping required for zinc-coated nuts in Specification A563. | |
7.4 The gaging limit for bolts and studs shall be verified during manufacture or use by assembly of a nut tapped as nearly as practical to the amount oversize shown above. In case of dispute, a calibrated thread ring gage of that same size (Class X tolerance, gage tolerance plus) shall be used. Assembly of the gage, or the nut described above, must be possible with hand effort following application of light machine oil to prevent galling and damage to the gage. These inspections, when performed to resolve disputes, shall be performed at the frequency and quality described in Table 5.
8. Number of Tests and Retests
8.1 The requirements of this specification shall be met in continuous mass production for stock, and the manufacturer shall make sample inspections to ensure that the product conforms to the specified requirements. Additional tests of individual shipments of material are not ordinarily contemplated. Individual heats of steel are not identified in the finished product.
8.2 When specified in the order, the manufacturer shall furnish a test report certified to be the last completed set of mechanical tests for each stock size in each shipment.
8.3 When additional tests are specified on the purchase order, a lot, for purposes of selecting test samples, shall consist of all material offered for inspection at one time that has the following common characteristics:
- One type of item,
- One nominal size, and
- One nominal length of bolts and studs.
8.4 From each lot, the number of tests for each requirement shall be as follows:
| Number of Pieces in Lot | Number of Samples |
|---|---|
| 800 and under | 1 |
| 801 to 8,000 | 2 |
| 8,001 to 22,000 | 3 |
| Over 22,000 | 5 |
| Lot Size | Sample SizeA | Acceptance Number |
|---|---|---|
| 2 to 90 | 13 | 1 |
| 91 to 150 | 20 | 2 |
| 151 to 280 | 32 | 3 |
| 281 to 500 | 50 | 5 |
| 501 to 1,200 | 80 | 7 |
| 1,201 to 3,200 | 125 | 10 |
| 3,201 to 10,000 | 200 | 14 |
| 10,001 and over | 315 | 21 |
| A Inspect all bolts in the lot if the lot size is less than the sample size. | ||
8.5 If any machined test specimen shows defective machining it shall be discarded and another specimen substituted.
8.6 Should any sample fail to meet the requirements of a specified test, double the number of samples from the same lot shall be tested, in which case all of the additional samples shall meet the specification.
9. Test Methods
9.1 Grades A and B bolts and studs shall be tested in accordance with Test Methods F606.
9.2 Standard square and hex head bolts only shall be tested by the wedge tension method except as noted in 6.4. Fracture shall be in the body or threads of the bolt without any fracture at the junction of the head and body. Other headed bolts shall be tested by the axial tension method.
9.3 Speed of testing as determined with a free running crosshead shall be a maximum of 1 in./min for the tensile strength tests of bolts.
10. Inspection
10.1 If the inspection described in 10.2 is required by the purchaser it shall be specified in the inquiry, order, or contract.
10.2 The inspector representing the purchaser shall have free entry to all parts of the manufacturer's works that concern the manufacture of the material ordered. The manufacturer shall afford the inspector all reasonable facilities to satisfy him that the material is being furnished in accordance with this specification. All tests and inspections required by the specification that are requested by the purchaser's representative shall be made before shipment, and shall be conducted as not to interfere unnecessarily with the operation of the works.
11. Responsibility
11.1 The party responsible for the fastener shall be the organization that supplies the fastener to the purchaser.
12. Rejection and Rehearing
12.1 Disposition of nonconforming lots shall be in accordance with Guide F1470, specifically sections on disposition of nonconforming lots, suppliers option, and purchasers option.
13. Product Marking
13.1 Grades A and B Bolts and Studs:
13.1.1 Bolt heads and one end of studs shall be marked with a unique identifier by the manufacturer to identify the manufacturer. Additional marking required by the manufacturer for his own use shall be at the option of the manufacturer.
13.1.2 In addition to the requirements of 13.1, all bolt heads, one end of studs 3/8 in. and larger, and whenever feasible studs less than 3/8 in. shall be marked with a grade marking as follows:
| Grade | Marking |
|---|---|
| A | 307A |
| B | 307B |
13.1.3 All markings shall be located on the top of the bolt head or stud end and shall be raised or depressed at the option of the manufacturer.
14. Packaging and Package Marking
14.1 Packaging:
14.1.1 Unless otherwise specified, packaging shall be in accordance with Practice D3951.
14.1.2 When special packaging requirements are required, they shall be defined at the time of the inquiry and order.
14.2 Package Marking:
14.2.1 Each shipping unit shall include or be plainly marked with the following information:
- ASTM designation and grade,
- Size,
- Name and brand or trademark of the manufacturer,
- Number of pieces,
- Purchase order number,
- Country of origin.
15. Keywords
15.1 bolts; carbon steel; steel; studs
SUPPLEMENTARY REQUIREMENTS
Supplementary Requirement S1 of an optional nature is provided, which describes additional restrictions to be applied when bolts are to be welded. It shall apply only when specified in the inquiry, order, and contract.
