ASME B18.5.2.1M:2006 pdf download

ASME B18.5.2.1M:2006 pdf download.Metric Round Head Short Square Neck Bolts
1 INTRODUCTORY NOTES
1.1 Scope 1.1.1 This Standard covers the general and dimen- sional data for metric series round head short square neckbolts recognized as anAmerican National Standard and intended primarily for applications in thin metals. 1.1.2 The inclusion of dimensional data in this Standard is notintended to imply thatall sizes described are production stock items. Consumers should consult with suppliers concerning lists of stock production items. 1.2 Comparison With ISO 8678:1988 1.2.1 Steel bolts produced to this Standard are functionally interchangeable with bolts which conform to ISO 8678:1988. Differences between this Standard and ISO 8678 are: size M14, materials other than steel, and minor variations in tolerances, such as, permissible swell, fin, or die seam on the body of bolts with nominal lengths longer than 150 mm. Dimensional require- ments in addition to, or different from ISO 8678, are shown in bold type in this Standard. 1.2.2 Letter symbols designating dimensional characteristics are in accordance with ISO 225 and ISO 8678, except where capitals have been used instead of the lowercase letters used in the ISO standards. 1.3 Terminology Fordefinitions ofterms relatingto fasteners or compo- nent features used in this Standard, refer to ASME B18.12. 1.4 Dimensions 1.4.1 All dimensions in this Standard are in milli- meters (mm), and apply to unplated or uncoated prod- uct, unless stated otherwise. 1.4.2 Symbols specifying geometric characteristics are in accordance with ASME Y14.5M. 1.5 Clearance Holes The recommended sizes of clearance holes in materi- als to be assembled, using round head short square neck bolts, are given in Nonmandatory Appendix B.
2 GENERAL DATA
2.1 Heads 2.1.1 Top ofHead. The spherical top surface of the head may be underfilled within a circle equal to the nominal bolt diameter, D, concentric to the bolt axis, providing the head height, K, is maintained. 2.1.2 Head Height. The head height is the distance, as measured parallel to the axis of the bolt, from the top of the head to the underhead bearing surface. See para. 2.11. 2.1.3 Edge of Head. The edge of the head may be flat or rounded, and the periphery may be somewhat irregular, providing the limits for head diameter, D k , bearing surface diameter, D w , and head edge thickness, C (measured at the minimum bearing surface diameter, D w min.), are maintained. 2.1.4 Bearing Surface. The bearing surface shall be reasonably flat and perpendicular within one degree to the axis ofthe bolt. A 0.5 mm maximum heightdie seam fin across the bearing surface shall be permissible.2.2 Square Neck 2.2.1 Depth of Neck. The depth of the square neck is the distance, measured parallel to the axis, from the bearing surface to the plane where the corner chamfer would intersect the nominal bolt diameter. 2.2.2 Corner Depth. The corner depth is the dis- tance, measured at a corner of the square, from the plane of the bearing surface to the last plane at which the width across corners, E, is within its specified limits. 2.2.3 Width Across Corners. The corners of the square neck may be rounded or underfilled to the extent allowed by the minimum width across corners, E, and the minimum corner depth, F 1 . There may be a fin or die seam on the corners of the square not to exceed the maximum width across corners. 2.3 Fillets The radius of fillets at the junction of head and square neck and at the junction of square neck and shank shall be within the specified limits, except for bolts produced from nonferrous and corrosion resistance materials, on which maximum fillets shall be subject to agreement between manufacturer and purchaser.