ASME B18.2.6-2019 pdf download
ASME B18.2.6-2019 pdf download.Fasteners for Use in Structural Applications.
Scope 1.1.1 This Standard covers the complete general and dimensional data for five products in the inch series recognized as an American National Standard. These five structural products include (a) heavy hex structural bolts: ASTM F3125/F3125M (b) heavy hex nuts: ASTM A563 and ASTM A194/A194M (c) hardened steel washers — circular, circular clipped, and beveled: ASTM F436/F436M (d) compressible washer-type direct tension indicators: ASTM F959/F959M (e) twist-off-type structural bolts — heavy hex and round: ASTM F3125/F3125M 1.1.2 The inclusion of dimensional data in this Standard is not intended to imply that all products described herein are stock production sizes. Consumers should consult with suppliers concerning lists of available stock production sizes. 1.2 Dimensions All dimensions in this Standard are in inches, unless stated otherwise, and apply to an unplated or uncoated product. When plating or coating is specified, the finished product dimensions shall be as agreed upon between supplier and purchaser. Symbols specifying geometric characteristics are in accord with ASME Y14.5. 1.3 Options Options, where specified, shall be at the discretion of the supplier, unless otherwise agreed upon by the purchaser with the manufacturer or distributor. 1.4 Terminology For definitions of terms relating to fastener dimensional or component features used in this Standard, refer to ASME B18.12. 1.5 Referenced Standards Unless otherwise specified, the referenced Standard shall be the most recent issue at the time of order placement. The following is a list of publications referenced in this Standard.
Heavy Hex Structural Bolt Dimensions Bolts shall conform to the dimensions given in Table 2.1-1. Formulas for heavy hex structural bolts are given in Nonmandatory Appendix A of ASME B18.2.1. 2.1.1 Top of Head. Top of head shall be full form and chamfered or rounded with the diameter of chamfer circle, or start of rounding being equal to the maximum width across flats within a tolerance of −15% of the maximum across flats dimension. The shape of the top of the head may be flat, concave, or convex at the manufacturer’s option. If the shape is concave or convex, head height as described in para. 2.1.4 shall remain within specified limits at lowest or highest points, respectively. 2.1.2 Width Across Flats. The width across flats of heads shall be the distance measured perpendicular to the axis of the overall product between the two opposite sides of the head. 2.1.3 Head Taper. The maximum width across flats shall not be exceeded. No transverse section through the head between 25% and 75% of actual head height, as measured from the bearing surface, shall be less than the minimum width across flats. 2.1.4 Head Height. The head height shall be that overall distance measured parallel to the axis of the product from the top of the head to the bearing surface and shall include the thickness of the washer face. Raised grade and manufacturer’s identification are excluded from head height. 2.1.5 True Position of Head. The head shall be located at true position with respect to the body within a tolerance zone having a diameter equivalent to 6% of the maximum width across flats at maximum material condition (MMC). For measurement purposes, hold the body a distance under the head equal to one diameter. 2.1.6 Bearing Surface. Bearing surface shall be flat and washer faced. However, a die seam across the bearing face shall be permissible. Diameter of washer face shall be equal to the maximum width across flats within a tolerance of −10%. Thickness of the washer face shall be not less than 0.015 in. Threads. Threads shall be cut or rolled in accordance with ASME B1.1 Unified Coarse, Class 2A. Structural bolts shall not be undersized to accommodate heavy coatings. Threads that have been coated shall meet the requirements specified in ASTM F3125/F3125M. 2.1.9.1 Thread Acceptability. Unless otherwise specified by the purchaser, gaging for screw thread dimensional acceptability shall be in accordance with Gaging System 21, as specified in ASME B1.3. 2.1.9.2 Thread Length. The length of thread on bolts shall be controlled by the grip gaging length, L G max., and the body length, L B min.