ASME B18.6.3-2013 pdf download

ASME B18.6.3-2013 pdf download.Machine Screws, Tapping Screws, and Metallic Drive Screws (Inch Series).
1 INTRODUCTORY NOTES 1.1 Scope This Standard is intended to cover the complete gen- eral and dimensionaldata forthe various types ofslotted and recessed head machine screws, tapping screws, and metallic drive screws recognized as American National Standard. Also included are appendices that provide specifications and instructions for the protrusion gaging of flat countersunk head screws; across-corners gaging ofhex head screws; penetration gaging and wobble gag- ing of recessed head screws; approximate hole size for tapping screws; wrench openings for hex and square products; thread dimensions for the No. 0000, No. 000, and No. 00 sizes; means for determining effective grip lengths on screws; documentation for screw types and head types relegated to not-recommended or limited-usage status; and formulas on which dimen- sional data are based. It shall be understood, however, that where questions arise concerning acceptance of product, the dimensions in the tables shall govern over recalculation by formula. The inclusion of dimensional data in this Standard is not intended to imply that all of the products described are stock production sizes. Consumers should consult with suppliers concerning the availability of products. 1.2 Dimensions All dimensions in this Standard are given in inches, unless stated otherwise. 1.3 Options Options, where specified, shall be at the discretion of the manufacturer unless otherwise agreed upon by the manufacturer and the purchaser. 1.4 Responsibility for Modification The manufacturer shall not be held responsible for malfunctions ofproduct determined to be due to plating or other modifications when such plating or modifica- tion is not accomplished under the manufacturer’s con- trol or direction. 1 1.5 Terminology For definitions of terms relating to fasteners or fea- tures thereofusedinthis Standard,refertoASME B18.12. 1.6 Comparison With ISO This Standard has no ISO counterpart. 1.7 Referenced Standards Unless otherwise specified, the standards referenced shall be the latest at the time of order placement. ASME B1.1, Unified Inch Screw Threads (UN and UNR Thread Form) ASME B1.3, Screw Thread Gaging Systems for Acceptability: Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ) ASME B18.2.9, Straightness Gage and Gaging for Bolts and Screws ASME B18.12, Glossary of Terms for Mechanical Fasteners ASME B18.18, Quality Assurance for Fasteners ASME B18.24, Part Identifying Number (PIN) Code System for B18 Fastener Products Publisher: The American Society of Mechanical Engineers (ASME), Two Park Avenue, New York, NY 10016-5990;OrderDepartment: 22 LawDrive,P.O. Box 2900, Fairfield, NJ 07007-2900 (www.asme.org) ASTM F1941, Specification for Electrodeposited Coatings on Threaded Fasteners [Unified Inch Screw Threads (UN/UNR)] Publisher: American Society for Testing and Materials (ASTM International), 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA, 19428-2959 (www.astm.org) SAE J423, Methods of Measuring Case Depth Publisher: SAE International,400 CommonwealthDrive, Warrendale, PA 15096-0001 (www.sae.org) 1.8 Inspection and Quality Assurance Unless otherwise specified, acceptability to this Standard shall be determined in accordance with ASME B18.18, Category 2 for manufacturers, plus all applicable material and/or mechanical tests indicated in this Standard.
2 GENERAL DATA FOR MACHINE SCREW AND TAPPING SCREW HEADS 2.1 Heads 2.1.1 Head Height. All dimensions pertaining to head height specified in the dimensional tables shall be measured parallel to the axis of the screw, and those relating to the top of the head shall represent a metal- to-metal measurement. In other words, any truncation of rounded head contours due to the slot or recess shall not be considered part of the head height. Total or overall head heights shall be measured from the top of the head to the plane of the bearing surface for flat bearing surface type heads, to the plane of the undercut for undercut countersunk heads, and to the junction of the conical bearing surface with the basic screw diameter for countersunk heads. Head side heights shallbe measuredfromthetheoreti- cal intersection of the top surface of the head with the head diameter to the plane of the bearing surface for flatbearingsurface type heads, to the plane ofthe under- cut for undercut countersunk heads, and to the junction ofthe conical bearing surface with the basic screw diam- eter for countersunk heads. On countersunk heads, the junction of the conical bearing surface with the basic screw diameter may not necessarily be the same as the actual junction of the head with the shank and the head height delineating the conical bearing surface is a reference dimension. 2.1.2 Bearing Surface. The bearing surface of flat bearing surface type screw heads shall be perpendicular to the axis of the screw shanks within 2 deg.