ASME B18.18.1-2007 pdf download

ASME B18.18.1-2007 pdf download.Inspection and Quality Assurance for General Purpose Fasteners.
This Standard outlines a Quality Assurance Plan for internally and externally threaded fasteners and accessories or associated parts. Provisions are included for sampling plans, inspection frequencies, control procedures, and record keeping.
Included in this plan are fasteners for general purpose applications, such as those where hand assembly is employed and cost is probably of prime consideration. This plan relies on judicious manufacturing controls and inspections by the producer and, should a dispute arise, provides an inspection plan for lot compliance after shipment.
This Standard will be used in conjunction with other accepted standards for product, testing, gaging, and material; therefore, those provisions, as well as packaging, 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 drawings and related specifications by the appropriate code letter at the time of ordering (see Nonniandatory Appendix B). To assist in arriving at the most appropriate inspection level, the Decision Table included in Non- mandatory Appendix A is recommended for guidance.
1.3 Lot Sizes
When the acceptance number For sampling by attributes i. fixed, variation in samplesize results in variation of acceptable quality. Therefore, to avoid this inconsistency, fixed sample sizes are applied For the greatest range of lot size. Sample sizes for lots up to 250,000 pieces are shown in Table 1; however, for lot sizes exceeding 250,000 pieces, Table 1, Note (2) shall apply.
1.4 Measuring and Testing Equipment
All inspection and testing equipment shall be calibrated and traceable to the National Institute of Standards and Technology (NIST) standard or an equivalent national or international Standard. All calibration procedures shall comply with the requirements of ISO 17025, General Requirements for the Competence of Testing and Calibration Laboratories.