ASME B18.18.2-2009 pdf download.Inspection and Quality Assurance for High-Volume Machine Assembly Fasteners.
1 GENERAL INFORMATION 1.1 Basic Plan Structure This Standard outlines a Quality Assurance Plan for internally and externally threaded fasteners and acces- sories or associated parts. Provisions are included for sampling plans, inspection frequencies, control proce – dures, and record keeping. Included in this plan are fasteners such as those where a more detailed inspection would enhance mass assem- bly operation. The quality assurance plan for these fas- teners relies primarily on increased final inspection rather than on documented in-process control. This Standard will be used in conjunction with other accepted standards for product, testing, gaging, and material and, therefore, those provisions as well as pack- aging are not included herein. 1.2 Inspection Levels The substantial difference in importance to the user of various characteristics and the dissimilar degrees of control in manufacture make impractical the subjecting of all characteristics to the same degree of inspection. Therefore, three inspection levels have been provided. Any additional characteristics deemed applicable by the user that do not appear in the plan shall be explicitly designated by the user, preferably on engineering draw- ings and related specifications by the appropriate code letter at the time of ordering (see Nonmandatory Appendix B). To assist in arriving at the most appro- priate inspection level, Fig. A-1 included in Nonmandatory Appendix A is recommended for guidance.
2 FASTENERS FOR HIGH-VOLUME MACHINE ASSEMBLY APPLICATIONS 2.1 Scope This Standard is an Acceptance Sampling Plan for high-volume machine assembly fasteners, accessories, and associated parts. It establishes specific inspection functions that must be performed on the finished prod- uct or at the appropriate stage of manufacturing with the objective of ensuring that the accepted product con- forms to all the requirements of engineering drawings, related standards, and/or specifications. This plan does not necessitate in-process control; how- ever, the producer, at his discretion, may apply in-process control. Adherence to the requirements of this plan does not release the contractor from the responsibil- ity of exercising due care in the production of all parts to the requirements established for all characteristics shown on engineering drawings and related specifications. 2.2 Applicable Characteristics Unless designated characteristics are specifically spec- ified in the product standard, the applicable characteris- tics include all characteristics of a part that are described by engineering drawings and related specifications. Three levels of inspection一A, B, and C一- are provided in the plan. Alternate levels may be designated by the user if required. Refer to Fig. A-1 in Nonmandatory Appendix A to establish alternate levels as required. Any additional characteristic(s) deemed applicable by the user and not appearing in the general plan, or charac- teristics for which the user requires an inspection level other than that designated in the plan, must be explicitly requested by the user and shown on drawings or specifi- cations by the appropriate code letter at the time of ordering (see Nonmandatory Appendix B).
2.5 Purchased Accessories and Parts Accessories, services, and partially fabricated parts (e.g.. washers, nuts, blanks, heat treating, plating, etc.) may be purchased by the prime contractor from subcon- tractors for use in the production of fasteners, provided the following conditions and requirements are met: (a) The prime contractor shall be responsible to the user for the quality of the final product. (b) The prime contractor shall be responsible for the implementation of all requirements of this plan, includ- ing records. (C) All lots that are heat treated and/or finished by a subcontractor and all lots that are processed by a sub- contractor following heat treatment and/or finishing operations shall undergo final inspection by the subcon- tractor or the prime contractor. 2.6 Raw Material 2.6.1 General. Raw material (rod, wire, or bar) shall be reviewed to determine that each coil or bundle has a mill identification and that each heat (batch, melt, cast, etc.) is accompanied by a mill certification of analysis or the equivalent. The raw material or its accompanying mill certification shall be inspected prior to release for fabrication to verify that it conforms to the material requirements specified. 2.6.2 General Quality. One fastener, taken at ran- dom from representative coils of rod or wire or from bundles of bars, shall be visually inspected to verify the general quality of the raw material and its condition following the forming process. The part shall be exam- ined for evidence of pipe, cracks, seams, and other sur- face discontinuities according to applicable specifications.