This Standard is intended to provide all users (manufacturers, distributors, design and configuration, parts control, inventory control, test and maintenance functions) with the capability to identify externally threaded, internally threaded, and non-threaded fastener products by a pre-selected order of coding as specified herein. The B18 PIN is a self-contained code, with distinct identification linkage to individual ASME B18 fastener product standards. The PIN code concept provides for direct traceability back to the applicable B18 product standard. In case of conflict with this document and B18 product standard, the B18 product standard shall take precedence. This Standard is not intended for use as a substitute for the correct usage of the B18 standards for fastener selection and specification. The PIN code is intended as an alternative to the plain text product callout as prescribed in the "Designation" or "Ordering" section of the source B18 product standard. The existence of a PIN code for B18 fastener description is not intended to imply that all products described are available. B18.24- 2004 is a consolidation of and update to B18.24.1-1996, PIN Code System Standard for B18 Externally Threaded Fastener Products, B18.24.2-1998, PIN Code System Standard for B18 Internally Threaded Fastener Products and B18.24.3-1998 PIN Code System Standard for B18 Non-Threaded Fastener Products. This publication is issued with an automatic addenda service. All addenda service publications are issued in loose leaf format to facilitate later insertion of replacement pages which incorporate the latest approved changes to the standard. Purchasers may wish to purchase a binder from ASME (ASME Binder), but the publication will also fit a standard three ring binder. Details on the specifics of the addenda service are as follows: