ASME B18.1 6M:2004 pdf free download

ASME B18.1 6M:2004 pdf free download.Prevailing- Torque Type Steel Metric Hex Nuts and Hex Flange Nuts.
7 WIDTH ACROSS FLATS
The width across flats shall be the distance, measured perpendicular to the axis of the nut, between two opposite wrenching flats. The maximum width across flats may be exceeded by 0.05 mm to allow for nut deformation caused by introduction of the prevailing-torque feature. The width across flats and width across corners may be less than the specified minimum in the deformed portion of the nut containing the prevailing-torque feature.
At maximum material condition the axis of the lwxagon shall be located at true position with respect to the axis of the thread pitch diameter within a tolerance zone having a diameter equivalent to 4% of the maximum width across flats.
8 THICKNESS
The nut thickness shall be the overall distance, measured parallel to the axis of the nut, from the top of the nut to the bearing surface of hex nuts, and to the plane of the bearing circle diameter of hex flange nuts. Raised identification markings, if present, shall be excluded.
9 WRENCHING HEIGHT
The wrenching height is the distance, measured at a corner of the hex, from the bearing surface of hex nuts, and from the junction of the hex portion with the flange of hex flange nuts to the last plane of full formed hex, i.e., the plane perpendicular to the nut axis that is closest to the top of the nut and at which the width across corners is within its specified limits. Wrenching height for hex nuts is dimension M1 in Table 1, and is subject to measurement. Wrenching height for hex flange nuts is dimension T in Table 2 and is controlled by the gaging requirement specified in para. 10.
10 GAGING OF HEX PORTION OF HEX FLANGE NUTS
The nut shall be gaged using two plain ring gages, A and B, to demonstrate the coincidental acceptability of hex height, wrenching height, and width across corners. (See figure above Table 2.) Gage A shall be placed over the hex and shall seat on the flange. Gage B shall be placed on the top of the nut normal to the nut axis. The two gages shall not be in contact.
NOTE; The minimum inside diameter of Gage A equals the maximum width across corners; the maximum inside diameter of Gage II equals the minimum width across corners minus 0.01 mm; the masimum thickness of Gage A was computed to be equal o or greater than the wrenching height necessary to provide sufficient driveability to develop two times the torsional strength of the properly ma ted, externally threaded component.