ASME B18.3-2003 pdf download

ASME B18.3-2003 pdf download.Socket Cap, Shoulder, and Set Screws，Hex and Spline Keys (Inch Series).
(14) See Table 7 for spline socket dimensions and Mandatory Appendix I for gaging of spline sockets.
(15) See Table 6 for hexagon socket dimensions and Mandatory Appendix I for gaging of hexagon sockets.
(16) Bearing Surface. The runout of the conical bearing surface shall be within I deg obtained by hoLding the screw on the body or major screw thread diameter within I diameter of the bearing surface of the head, but beyond the maximum length of the fillet, F, rotating 360 deg and inspecting on an optical comparator, or comparable inspection equipment.
(17) Runout
(a) The runout of the socket with the axis of the shank of the screw shall be within 3% of the maximum screw diameter, D, or 0.005 in., whichever is greater for nominal sizes through 1/2 in. diameter and 6% for nominal sizes above 1/ in. diameter.
Runout for (a) above is defined as the full indicator movement (FIM) obtained by holding the screw on the body or major thread diameter within 1 diameter of the bearing surface of the head, but beyond the maximum length of the fillet, F, rotating 360 deg, indicating on each of the six hexagon flats.
(b) The conformance of screws to shank straightness or camber limitations shall be as set forth as De in Table IE (Socket Head Cap Screws), and shall be checked by the use of the procedures and typical gage illustrated in Mandatory Appendix III.
(18) Threads. Threads shall be Unified external threads with radius root: Class 3A UNRC and UNRF Series for sizes 0 (0.060 in.) through I in.; Class 2A UNRC and UNRF Series for sizes over 1 in. to 11/2 in., inclusive.
Acceptability shall be based on System 22, ASME B1.3M.
Class 3A does not provide a plating allowance. When plated products are required, it is recommended that they be procured from the manufacturer (see para. 1.10, Introductory Notes).
(19) Material
(a) Steel, Alloy. Flat countersunk head cap screws shall be fabricated from an alloy steel and shall conform in all respects to ASTM F 835.
(b) Steel, Corrosion-Resistant. Flat countersunk head cap screws shall be fabricated from austenitic corrosion-resitant steel and shall conform in all respects to ASTM F 879.
(20) Dimensional Conformance. Flat Countersunk Socket Head Cap Screws shall have the following designated characteristics inspected to ASME B18.18.2M to Inspection Level C: threads, protrusion /flushness, socket size (gaged), and length.
(21) Designation. To promote uniformity and understanding in communications relating to products conforming to this Standard, it is recommended that Hexagon and Spline Flat Countersunk Socket Head Cap Screws be designated in accordance with the following data, preferably in the sequence shown:
(a) product name
(b) designation of the standard
(c) nominal size (number, fractional or decimal equivalent)
(d) thread pitch
(e) nominal length (fractional or decimal equivalent)
(19 material
(g) protective finish, if required
EXAMPLES:
Hexagon Socket Flat Countersunk Head Cap Screws, ASME B18.3, 1/4.28 x 14, Alloy Steel
Hexagon Socket FLat Countersunk Head Cap Screws, ASME B18.3, 0.250-28 x 1.750, Corrosion-Resistant Steel
Hexagon Socket Flat Countersunk Head Cap Screws, ASME B18.3, 6-32 x 0.500, Alloy Steel, Zinc Plated. (For plated products, see para. 1.7, Introductory Notes.)
For the recommended B18 part identifying numbering system (PIN), see ASME B18.24.1.
GENERAL NOTES:
(a) This product is designed and recommended for light fastening applications such as guards, hinges, etc. It is not suggested for use in critical high strength applications where socket head cap screws should normally be used.
(b) For additional requirements, refer to Notes (3) and (5) through (15) and section 2, General Data, of this Standard.
NOTES:
(1) Length. The length of the screw shall be measured, parallel to the axis of the screw, from the pLane of the bearing surface under the head to the plane of the flat of the point. The portion of the screw contained within dimension L is commonly called the shank. The basic length dimension on the product shall be the nominal length expressed as a two-place decimal.
(2) Standard Lengths. Standard length increments for socket button head cap screws shall be as tabulated below.