1.1.1 ASME B18.3 covers complete general and dimensional data for various types of hexagon and spline (fluted) socket cap screws, shoulder screws, set screws, and hexagon and spilne keys recognized as American National Standard. Also included are appendixes that provide specifications for hexagon and spline socket gages and gaging, tables showing applicability of keys and bits to various socket screw types and sizes, drill and counterbore sizes for socket head cap screws, and formulas on which dimensional data are based.However, where questions arise con-cerning acceptance of product, the dimensionsin the tables shall govern over recalculation byformula.
1.1.2The inclusion of dimensional data in thisstandard is not intended to imply that all of theproducts described are stock production sizes.Consumers should consult with manufacturersconcerming lists of stock production sizes.
Socket Cap Screws
The head types covered by this standardinclude 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, pages G—4 thru G—11. Both hexagon and spline socket types are included.
Dimensions for drilled holes and counter- bores are included in Appendix A, Table Al page
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, page G—11.
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, pages G—1 5 thru G—1 9. 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, page G—20. 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 height 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, page G—23.
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 5C, pages G—26 thru G—31, for both hexagon and spline socket types.
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 9, respectively, pages G—35 and G—37.
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 thru 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 manufacturers option. Products shall not be marked on bearing surface.
1.9 Options.