ASTM F879-15(R2020) pdf free download
ASTM F879-15(R2020) pdf free download.Standard Specification for Stainless Steel Socket Button and Flat Countersunk Head Cap Screws
1. Scope
1.1 This specification covers the chemical and mechanical requirements for stainless steel inch hexagon socket button (SBHCS) and flat countersunk (SFHCS) head cap screws with nominal thread 0.060 through 0.625 in. intended for use in applications requiring general corrosion resistance. 1.2 Two groups of austenitic stainless steel alloys and three conditions are covered. See Table 1 and Table 2. 1.3 Units—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 following precautionary caveat pertains only to the test method portion, Section 12, of this specification: This standard does not purport to address all ofthe safety concerns, ifany, associated with its use. It is the responsibility ofthe 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 accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
9. Dimensions
9.1 Unless otherwise specified, the dimensions shall con- form to the requirements of ASME B18.3.
10. Workmanship and Finish
10.1 Surface Treatment—Unless otherwise specified, screws shall be cleaned, descaled, and passivated in accordance with Practice A380/A380M or Specification A967/A967M at the option of the manufacturer. 10.2 Surface Discontinuities: 10.2.1 The surface discontinuities for these products shall conform to Specification F788 and the additional limitations specified herein. 10.2.1.1 Forging defects that connect the socket to the periphery of the head are not permissible. Defects originating on the periphery and with a traverse indicating a potential to intersect are not permissible. Other forging defects are permis- sible provided those located in the bearing area, fillet, and top surfaces shall not have a depth exceeding 0.03 D or 0.005 in. whichever is greater. For peripheral discontinuities, the maxi- mum depth may be 0.06 D (see Fig. 1). 10.2.1.2 Forging defects located in the socket wall within 0.1 times the actual key engagement, T, from the bottom of the socket are not permissible. Discontinuities located elsewhere in the socket shall not have a length exceeding 0.25 T, or a maximum depth of 0.03 D not to exceed 0.005 in. (see Fig. 2). 10.2.1.3 Seams in the shank shall not exceed a depth of0.03 D or 0.008 in. whichever is greater. 10.2.1.4 No transverse discontinuities shall be permitted in the head-to-shank fillet area. 10.2.1.5 Threads shall have no laps at the root or on the flanks, as shown in Fig. 3. Laps are permitted at the crests (Fig. 3(C)) that do not exceed 25 % ofthe basic thread depth, and on the flanks outside the pitch cylinder. Longitudinal seams rolled beneath the root of the thread and across the crests of the threads are acceptable within the limits of 10.2.1.3.
11. Number of Tests
11.1 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 fasteners are not ordinarily necessary. A record of the individual heat of steel in each lot shall be maintained. The containers shall be coded to permit identifi- cation of the lot. 11.2 When specified in the purchase order, the manufacturer shall furnish a test report of the last complete set of chemical analysis and mechanical tests for each stock size in each shipment. 11.3 When tests of individual shipments are required, Supplementary Requirement S1 must be specified in the inquiry and order. 11.3.1 When the purchaser does not specify the sampling plan and basis of acceptance, the following shall apply: 11.3.1.1 The lot, for purposes of selecting samples, shall consist of all products offered for inspection and testing at one time that are of the same type, style, nominal diameter, thread pitch, nominal length, material, condition, and surface finish.