ASME B18.3-2003

ASME B18.3-2003 Adobe PDF version*
*Reprinted from ASME B18.3-2003, by permission of The American Society of Mechanical Engineers. All rights reserved.

	ASME B18.3-2003
	SOCKET CAP, SHOULDER, AND SET SCREWS, HEX AND SPLINE KEYS (INCH SERIES)
	1 INTRODUCTORY NOTES 1.1 Scope 1.1.1 This Standard covers complete general and dimensional data for various types of hexagon and spline (fluted) socket cap screws, shoulder screws, set screws, and hexagon and spline keys recognized as American National Standard. Also included are appendices that provide specifications for hexagon and spline socket gages and gaging, tables showing applicability of keys and bits to various socket screws types and sizes, drill and counterbore sizes for socket head cap screws, and formulas on which dimensional data are based. However, where questions arise concerning acceptance of product, the dimensions in the tables shall govern over recalculation by formula. 1.1.2 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 manufacturers concerning lists of stock production sizes. 1.2 Socket Cap Screws The head types covered by this Standard include the following. 1.2.1 Socket Head Cap Screws. The socket head shall have flat chamfered top surface with smooth or knurled cylindrical sides and a flat bearing surface. Specifications are given in Tables IA through IF. Both hexagon and spline socket types are included. Dimensions for drilled holes and counterbores are included in Table A-1 of Nonmandatory Appendix A. 1.2.2 Drilled Hexagon Socket Head Cap Screws. Specifications for hexagon socket head cap screws having; 2, 4, and 6 holes drilled in the head for lock wire application are given in Table IF. 1.2.3 Socket Flat Countersunk Head Cap Screws. The flat countersunk head shall have a flat top surface and a conical bearing surface with included angle of approximately 82 deg. Specifications are given in Tables 2A, 2B, and 2C. Both hexagon and spline socket types are included. 1.2.4 Socket Button Head Cap Screws. The button head shall have a low rounded top surface with a large flat bearing surface. Specifications are given in Table 3. Both hexagon and spline socket types are included.	~~1.2.5 Socket Low Head Cap Screws~~ These are similar to socket head cap screws, except they have reduced head height and a smaller socket size. They are designed to be used in applications where heights clearance is a problem. Specifications are given in Table 1G. Spline socket types are excluded. ~~1.3 Socket Head Shoulder Screws~~ ~~The socket head shoulder screw is a hexagon socket head screw having a cylindrical shoulder under the head. Specifications are given in Table 4.~~ 1.4 Socket Set Screws The socket set screw is a screw threaded the entire length except for its length of point. The point is designed to bear on a mating part. The common point styles are cup, flat, oval, cone, and half dog. Specifications for set screws are shown in Tables 5A , through Table 5C for both hexagon and spline socket types. 1.5 Keys and Bits for Driving Socket Screws The tools for driving socket screws are hexagon or spline keys and bits, the specifications for which appear in Tables 8 and Table 9, respectively. 1.6 Dimensions All dimensions in this Standard are given in inches unless stated otherwise. All dimensions apply prior to coating unless stated otherwise. 1.7 Finish Because of the high hardness of these products, it is recommended that they not be electroplated. 1.8 Identification Marking Products described in paras. 1.2.1 through 1.2.4 and 1.3 with diameters larger than #10 must be marked with the identification of the source manufacturer or private label distributor accepting the responsibility for conformance to this Standard. Marking size, type, and location of marks are at manufacturer's option. Products shall not be marked on bearing surface. 1.9 Options Options, where specified, shall be at the discretion of the manufacturer unless agreed upon otherwise by the manufacturer and purchaser.
	**Text with strikethrough does not pertain to Cam-Tech's product line.**
	*Reprinted from ASME B18.3-2003, by permission of The American Society of Mechanical Engineers. All rights reserved.
	Page 1

		SOCKET CAP, SHOULDER, AND SET SCREWS, HEX AND SPLINE KEYS (INCH SERIES)
	ASME B18.3-2003
	1.10 Responsibility for Modifications The manufacturer shall not be held responsible for malfunctions of product due to plating or other modifications, when such plating or modification is not accomplished under his control or direction. 1.11 Terminology For definitions of terms relating to fasteners or to component features thereof used in this Standard, refer to ASME B18.12, Glossary of Terms for Mechanical Fasteners. 1.12 Referenced Standards The following is a list of publications referenced in this Standard. Unless otherwise specified, the most recent standard available shall be used. ASME B1.1, Unified Inch Screw Threads (UN and UNR Thread Form) ASME B1.3M, Screw Thread Gaging Systems for Dimensional Acceptability - Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ) ANSI B18.12, Glossary of Terms for Mechanical Fasteners ASME B18.18.1M, Inspection and Quality Assurance for General Purpose Fasteners ASME B18.18.2M, Inspections and Quality Assurance for High Volume Machine Assembly Fasteners ASME B18.18.3M, Inspection and Quality Assurance for Special Purpose Fasteners ASME B18.18.4M, Fasteners Produced from a Single Mill Heat With In-Process Control and Lot Traceability ASME B18.24.1, Part Identifying Number (PIN) Code System Standard for B18 Externally Threaded Products ASME B46.1, Surface Texture ASME B47.1, Gage Blanks ASME Y14.5M, Engineering Drawings and Related Documentation Practices, Dimensioning and Tolerancing ASME Y14.6, Engineering Drawing and Related Documentation Practices, Screw Thread Representation Publisher: The American Society of Mechanical Engineers (ASME), Three Park Avenue, New York, NY 10016-5990; Order Department: 22 Law Drive, Box 2300, Fairfield, NJ 07007-2300 ASTM A 574, Standard Specification for Alloy Steel Socket-Head Cap Screws ASTM F 835, Standard Specification for Alloy Steel Socket Button and Flat Countersunk Head Cap Screws ASTM F 837, Standard Specification for Stainless Steel Socket-Head Cap Screws ASTM F 879, Standard Specification for Stainless Steel Socket Button and Flat Countersunk Head Cap Screws ASTM B880, Standard Specification for Stainless Steel Socket Set Screws ASTM F 912, Standard Specification for Alloy Steel Socket Set Screws	Publisher: The American Society for Testing and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959 2 GENERAL DATA 2.1 Sockets In accordance with the provisions set forth in the notes to the respective dimensional tables, screws shall have hexagon or spline sockets as designated by the purchaser. Gages and gaging procedures are included in Mandatory Appendix I, except having minimum dimensions equal to minimum sizes of keys and bits shown in Table 8 and Table 9, respectively. Due to possible buildup of the socket, coated products may not accept a standard hex or spline key. 2.1.1 Hexagon Sockets. Hexagon sockets shall conform with the specifications given in Table 6. 2.1.2 Spline Sockets. Spline sockets shall conform with the specifications given in Table 7. 2.2 Threads Threads on all screw products covered in this Standard shall be in accordance with ASME B1.1 for the series and class specified in the notes to the respective product dimensional tables. Acceptability of screw threads shall be based on System 22, ASME B1.1, except where otherwise specified in Note (14) of Table 5A. 2.3 Quality Assurance Products will be furnished in accordance with ASME B18.18. 1M and thread acceptability to Inspection Level C, unless otherwise specified. 2.4 Dimensional Characteristics Products shall conform to the dimensions indicated in the respective tables. The designated characteristics defined within the notes of each product table shall be inspected in accordance with ASME B18.18.2M. For nondesignated dimensional characteristics the provisions of ASME B18.18.1M shall apply. Should a nondesignated dimension be determined to have a variance, it shall be deemed conforming to this Standard if the user, who is the installer accepts the variance based on fit, form, and function considerations. Where verifiable in-process inspection is used in accordance with ASME B18.18.3M or ASME B18.18.4M, the final inspection level sample sizes of those respective standards shall apply.
	**Text with strikethrough does not pertain to Cam-Tech's product line.**
	*Reprinted from ASME B18.3-2003, by permission of The American Society of Mechanical Engineers. All rights reserved.
	Page 2