①,Where specifying nominal size in decimals, zeros preceding the decimal and in the fourth decimal place shall be omitted. ②,No extrusion of excess metal beyond the apex of the point resulting from thread rolling shall be permissible . A slight rounding or truncation of the point is desirable. ③,The width of flat at crest of thread shall not exceed 0.004 in. for sizes up to and including No. 8, and 0.006 in. for larger sizes. ④,For screws of norminal lengths equal to or shorter than the nominal screw lengths, L0, listed in Table, the full-form threads shall extend close to the head such that the minor diamter limits of the specified thread are maintained to within Y daistance from the underside of the head, or closer if practicable. Screws of nominal lengths, L0, longer than those tabulated in table shall have a minimum length of full-form thread as shown in the "b Min" column of table, unless otherwise specified by the purchaser. ⑤,A slight rounding of all edges and comers of the hex surfaces of indented hex heads shall be permissible, provided the diameter of the bearing circle is equal to no less than 90% of the specified minimum width-across-flats dimension. |