ASME B18.6.3-2003 pdf free download.Machine Screws and Machine Screw Nuts
This Standard is intended to cover the complete gen- eral and dimensionaldata forthe various types ofslotted and recessed head machine screws and machine screw nuts recognized as American National Standard. Also included are appendices that provide specifications and instructions for the protrusion gaging of flat count- ersunk head screws; across-corners gaging of hex head screws; penetration gaging and wobble gaging of recessed head screws; wrench openings for hex and square products; thread dimensions for the No. 0000, No. 000, and No. 00 sizes; and formulas onwhich 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 Machine Screw Head Types The head types covered bythis Standard include those commonly recognized as being applicable to machine screws and are enumerated and described in the follow- ing paragraphs.
1.2.1 Flat Countersunk Head. The flat countersunk head has a flat top surface and a conical bearing surface with a head angle for one style of approximately 82 deg and for another style of approximately 100 deg. Dimensions are given in Tables 1A through 1E, and 2A through 2D, respectively. Dimensions of close tolerance 100 deg flat countersunk heads are given in Tables 3A through 3D.
1.2.2 Oval Countersunk Head. The oval countersunk head has a rounded top surface and a conical bearing surface with a head angle of approximately 82 deg. Dimensions are given in Tables 4A through 4E.
1.2.3 Undercut Flat and Oval Countersunk Heads. For short lengths, 82 deg flat and oval countersunk head machine screws have heads undercut to 70% of normal side height to afford greater length of thread on the screws. Dimensions are given in Tables 5A through 5E, and 6A through 6E, respectively.
1.2.4 Flat and Oval Countersunk Trim Heads. Flat and oval countersunk trim heads are similar to the 82 deg flat and oval countersunk heads except that the size of head for a given size screw is one or two sizes smaller than the regular flat and oval countersunk head size, and oval countersunk trim heads have a controlled radius where the curved top surface meets the conical bearing surface. Trim heads are furnished only in cross recessed head types. Dimensions are given in Tables 7A through 7C, and 8A through 8C, respectively.
1.2.5 Pan Head. The slotted pan head has a flat top surface rounded into cylindrical sides and a flat bearing surface. The recessed pan head has a rounded top surface blending into cylindrical sides and a flat bearing surface. Dimensions are given in Tables 9A through 9H.
1.2.6 Fillister Head. The fillister head has a rounded top surface, cylindrical sides, and a flat bearing surface. Dimensions are given in Tables 10A through 10E. Dimensions of drilled fillister head machine screws are given in Table 11.
1.2.7 Truss Head. The truss head has a low rounded top surface with a flat bearing surface, the diameter of which for a given screw size is larger than the diameter of the corresponding pan head. Dimensions are given in Tables 12A through 12G.
1.2.8 Binding Head. The binding head has a rounded top surface and slightly tapered sides. The bearing sur- face is flat and, where so specified by purchaser, slotted heads shall have an annular undercut adjacent to the shank. Dimensions are given in Tables 13A through 13E.
1.2.9 Hex Head. The hex head has a flat or indented top surface, six flat sides, and a flat bearing surface. Dimensions for regular and large heads are given in Tables 14A through 14C.
1.2.10 HexWasherHead. The hex washer head has an indented top surface and six flat sides formed integrally with a flat washer that projects beyond the sides and provides a flat bearing surface. Dimensions are given in Tables 15A through 15C. ASME B18.6.3 pdf download.ASME B18.6.3-2003 pdf free download
