Abstract： ASME B18.2.3.4M:2001 pdf download.METRIC HEX FLANGE SCREWS. 9 CORNER FILL The rounding due to lack of Iii at the six corners of the head shall be reasonably unilinn, 10 GAGING OF HEX FLANGE HEAD See Table I. The head shall be gaged using tw...

ASME B18.2.3.4M:2001 pdf download.METRIC HEX FLANGE SCREWS.

9 CORNER FILL

The rounding due to lack of Iii at the six corners of the head shall be reasonably unilinn,

10 GAGING OF HEX FLANGE HEAD

See Table I. The head shall be gaged using two ring gages. A and B, to demonstrate the coincidental acceptability of wrenching

height. corner fill and width across corners. (iagc A shall be placcd over the head and shall seat on the flange Gage B shall be

placed on the top of the head normal to the screw axis The two gages shall not be in contact.

11 POSITION OF HEAD

At maximum material condition, the axis of the hexagon of the head shall be within a positional toler’ ance zone of the diameter

specific in Table 2 with respect to the axis of the shank over a distance under the head equal to the nominal screw dianieter. D.

The datum shall be as close to the head as practicablc, but within O.5D from the head, and shall be either wholly plain body o

wholly the thread pitch diameter, not including the thread runout or the underhead fillet

12 FLANGE

The top surface o1 the hang shall be conical or slightly rounded (convex), Radius. R. applies both at the corners and at the flat

of the hexagon. The contour of edge at hang periphery, between the maximum hang diameter. D nuixintuin, and the minimum bearing

circle diameter. !) minimum, shall be optional provided ih.ii the minimum flang edge thickness. C minimum. is maintained at the

minimum bearing circle diameter. D,. minimum.

13 BEARING SURFACE

The bearing surface shall be conical. 0.75 ±0.50 deg concave from the plane fonned by the bearing circle diitmneter. The plane

funned by the bearing circle shall bc perpendicular to the axis of the shank, over a length under the head equal to the nominal

screw diameter within the circular runout as specific in Table 2. The measLiremeni of bearing face runoul shall be made at the

actual bearing circle (i.e.. at the line of highest points on any radial line. e.g.. by usc of straight edge anvil).

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