ASTM F835-23

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F835 − 20 F835 − 23
Standard Specification for
Alloy Steel Socket Button Button, Low and Flat
Countersunk Head Cap Screws
This standard is issued under the fixed designation F835; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 This specification covers the requirements for quenched and tempered alloy steel hexagon socket button (SBHCS) 0.060
through 0.625 thread sizes and sizes, flat countersunk (SFHCS) 0.060 through 1.5 thread sizes and low (SLHCS) 0.1120 through
0.625 thread sizes head cap screws having material properties for high-strength requirements.
1.2 Fasteners meeting this specification are intended for shear-type applications and have tensile requirements ranging from 122
to 150 ksi.
1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this
standard.
1.4 The hazard statement applies only to the test method section, Section 11, of this specification. This standard does not
purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to
establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior
to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
A751 Test Methods and Practices for Chemical Analysis of Steel Products
D3951 Practice for Commercial Packaging
E18 Test Methods for Rockwell Hardness of Metallic Materials
E112 Test Methods for Determining Average Grain Size
F606/F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners,
Washers, Direct Tension Indicators, and Rivets
F788 Specification for Surface Discontinuities of Bolts, Screws, Studs, and Rivets, Inch and Metric Series
This specification is under the jurisdiction of ASTM Committee F16 on Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts, Nuts, Rivets
and WashersStuds and Nuts.
Current edition approved Aug. 1, 2020June 1, 2023. Published August 2020July 2023. Originally approved in 1986. Last previous edition approved in 20182020 as
F835 – 18.F835 – 20. DOI: 10.1520/F0835-20.10.1520/F0835-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F835 − 23
F2328 Test Method for Determining Decarburization and Carburization in Hardened and Tempered Threaded Steel Bolts,
Screws, Studs, and Nuts
2.2 ASME Standards:
B18.3 Socket Cap, Shoulder and Set Screws—Inch Series
B18.24 Part Identifying Number (PIN) Code System Standard for B18 Fastener Products
3. Ordering Information
3.1 Orders for material under this specification shall include the following:
3.1.1 Quantity (number of screws).
3.1.2 Dimensions, including nominal thread designation, thread pitch, and nominal screw length (inches). A standard part number
may be used for this definition.
3.1.3 Name of the screw: SBHCS SBHCS, SLHCS or SFHCS.
3.1.4 Coating, if required. If a protective finish other than black oxide is required, it must be specified on the order or product
standard.
3.1.5 Lot testing, if required (see 10.3).
3.1.6 Certification, if required (see 14.1).
3.1.7 ASTM designation and year of issue.
3.1.8 Any special requirements.
3.1.9 For establishment of a part identifying system, see ASME B18.24.
3.2 Example—1000 pieces 0.250 − 20 × 0.375 SBHCS lot tensile test. ASTM F835–XX.
4. Materials and Manufacture
4.1 The screws shall be fabricated from alloy steel made to fine grain practice. In the event of controversy over grain size, referee
tests on finished screws conducted in accordance with Test Methods E112 shall prevail.
4.2 Screws shall be hot or cold upset or extruded, or both.
4.3 Unless otherwise specified, threads shall be rolled for diameters through 0.625 in. and for screw lengths through 4 in. For
diameters and lengths other than this, threads may be rolled, cut or ground.
4.4 Screws shall be heat treated by quenching in oil from above the transformation temperature and then tempering by reheating
to at least 650°F to be within the hardness range specified in Table 1.
4.4.1 The minimum tempering temperature may be verified by submitting screws to 635°F for 30 min at temperature. The average
cross-section hardness of three readings on the screw before and after retempering shall not differ by more than 20 DPH.
4.5 When protective or decorative coatings are applied to the screws, precautions as required by the coatings shall be taken to
prevent embrittlement.
5. Chemical Composition
5.1 The chemical composition of the screw material shall conform to the heat analysis specified in Table 2.
Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
www.asme.org.
F835 − 23
TABLE 1 Mechanical Requirements
Nominal Thread Size, in.
0.500 and Over 0.500
smaller
Full-size Screws:
Tensile, min, ksi 144 136
Machined Test Specimen:
A
Yield strength at 0.2 % offset, min, ksi 153
A
Tensile strength, min, ksi 170
A
Elongation in 4 D, min, % 8
A
Reduction of area, min, % 35
Product Hardness:
Rockwell C 39–44 37–44
Vickers DPH 382–434 363–434
A
Not applicable.
TABLE 2 Chemical Requirements
Composition, %
Element
Heat Product
Analysis Analysis
Carbon 0.30 to 0.48 0.28 to 0.50
Phosphorus, max 0.035 0.040
Sulfur, max 0.040 0.045
Alloying elements see 5.2 see 5.2
5.2 One or more of the following alloying elements, chromium, nickel, molybdenum, or vanadium, shall be present in the steel
in sufficient quantity to ensure the specific strength properties are met after oil quenching and tempering. The steel shall meet the
AISI definition of alloy steel, that is, maximum and minimum element content requirement or minimum element limits specified.
5.3 Steel to which bismuth, selenium, tellurium, or lead has been added intentionally shall not be permitted.
5.4 Material analysis may be made by the purchaser from finished products and the chemical composition thus determined shall
conform to the requirements specified for the product analysis in Table 2.
6. Mechanical Properties
6.1 The finished screws shall conform to the mechanical requirements specified in Table 1.
6.2 Screws having a nominal length equal to or greater than 3 diameters shall be tested full size and shall conform to the full-size
tensile requirements specified in Table 3. Tensile failures through the head are acceptable provided the load requirements are
satisfied.
6.3 Screws having a nominal thread diameter-length combination as specified in 6.2 and a breaking load exceeding 200 000 lb
preferably shall be tested full size and shall meet the full-size tensile properties in Table 3. When equipment of sufficient capacity
for such tests is not available or if excessive length of the screws makes full-size testing impractical, standard round machined
specimens may be used that shall meet the machined test specimen tensile properties in Table 1. If discrepancy between full-size
and machined specimen results, full-size tests shall be used as the referee method to determine acceptance.
6.4 Screws that are too short (lengths less than three times nominal size) or that have insufficient threads for tension testing shall
not be subject to tension tests but shall conform to the hardness (minimum and maximum) requirements of Table 1.
6.5 All screws, regardless of size, shall conform to the hardness specified in Table 1. Hardness shall be met anywhere on the cross
section through the threaded portion one diameter from the screw point.
F835 − 23
TABLE 3 Minimum Ultimate Tensile Loads
Button and Button, Low and Flat Countersunk
B 2
Thread Size Stress Area, in. Heads, Tensile Load,
A
min lb
Coarse
Fine Thread
Coarse Fine Coarse Fine Thread
Series
Series
. . . 0.060-80 . . . 0.00180 . 260
0.073-64 0.073-72 0.00263 0.00278 380 400
0.086-56 0.086-64 0.00370 0.00394 530 570
0.099-48 0.099-56 0.00487 0.00523 700 750
0.112-40 0.112-48 0.00604 0.00661 870 950
0.125-40 0.125-44 0.00796 0.00830 1150 1200
0.138-32 0.138-40 0.00909 0.01015 1310 1460
0.164-32 0.164-36 0.0140 0.01474 2020 2120
0.190-24 0.190-32 0.0175 0.0200 2520 2900
0.250-20 0.250-28 0.0318 0.0364 4580 5240
0.3125-18 0.3125-24 0.0524 0.0580 7550 8350
0.375-16 0.375-24 0.0775 0.0878 11 200 12600
0.4375-14 0.4375-20 0.1063 0.1187 15 300 17100
0.500-13 0.500-20
...