ASME B18.2.5M:2013 pdf free download

ASME B18.2.5M:2013 pdf free download.Metric 12-Point Flange Head Screws.
14 BODY DIAMETER
The diameter of the body, V.. on screws that are not threaded full length shall be within the limits specified in Table 1, unless the purchaser specifies screws with reduced diameter body. Fcr screws threaded full length. the dianwter of the unthreaded shank under the head shall neither exceed the maximum body diameter. D, maximum, specified in Table I, nor be less than the minimum body diameter, 1). minimum, specified in Table 5. Screws of nominal lengths equal to or greater than the shortest nominal lengths specified in Table 6 maybe obtained with reduced diameter bod if so speciuied. Where reduced diameter body (or l\rpe R”) is specified, the body diameter. D2, shall be within the limits specified in Table 6. The screw shaLl have a shoulder under th head. The diameter, U, and length, L2, of the shoulder shall he as specilied in Table 6,
15 LENGTH
The length of the screw is the distance, parallel to the axis of the screw, from the pbne formed by the underhead hearing circle diameter to the extreme end of the screw. Tolerances br screw lengths are specified in Table 7.
16 POINTS
The end of the screw shall be chamfered or rounded at the manulacturer’s option from approximately 0.40 mm below the minor diameter of the thread. The length of the point to the first full-formed thread at ma;or diameter, as determined by the distance the point enters into a cylindrical NOT CO mapor diameter ring gage, shall not exceed U maximum, specified in TableS. The end of the screw shall be reasonably square with the axis of the screw, and where pointed blanks are used, the slight rim or cup resulting from roll threading shall be permissible. At the manufacturer’s option, the end of the screw may have a rounded point of radius. R,., as specified in Table 8.
17 STRAIGHTNESS
At maximum material condition, the derived median line of the screw body and thread major diameter shall be within a straightness tolerance ione of a diameter equal to 0.006 times length, expressed as a two-place decimal.
A gage and gaging procedure for checking screw straightness are given in ASME Bl8.2.9.
19.3 Thread Length,B
The thread length,B, specified in Table 10, is a refer-ence dimension intended for calculation purposes only,and is the distance,parallel to the axis of the screw,from the extreme end of the screw to the last complete(full-form) thread.
19.4 Transition Thread Length,x
The transition thread length,X,specified in Table 10, isa reference dimension intended for calculation purposesonly. It includes the length of incomplete threads andtolerances ongrip length and body length. The transitionfrom full-form thread to incomplete thread shall besmooth and uniform.The major diameter of the incom-plete threads shall not exceed the actual major diameterof the complete (full-form) threads.The transitionthreads shall have a rounded root contour.