Downloaded from https://www.everyspec.com MIL-STD-3001-4(AS) f. Quantities of attaching parts shall be listed per unit (piece) only. For example, if two fittings are required for each preceding assembly and one bolt is required to attach both fittings, the correct listing is as follows: UNITS PER DESCRIPTION ASSY FITTING ASSY, HINGE 2 (ATTACHING PARTS) BOLT 1 ---*--- 5.3.11.1.5 Usable on code. Usable on codes for assemblies and parts to indicate their specific usability with the end item to which the IPB figure applies shall be listed as an entry under a heading "USABLE ON CODE." Capital letters shall be used to identify the application of the items.
If single letters of the alphabet are not sufficient to complete coding, double letters may be used. e.g., AA, AB, etc. The letters O and I shall not be used singularly or in pairs. No usable on code shall be used for assemblies and parts that are applicable to all end items. a. Simple application. When different end item part numbers are identified, each end item will be assigned a code in sequence and that code will be listed for each peculiar item in the parts list. More than one code may be assigned to the same item, e.g., A, B or A, C. b. Redesigned parts.
If the original part has continued application, the applicable model, block numbers, and serial numbers of the items on which the part is usable shall be indicated by usable on codes. c. Alternate parts. An alternate part is defined as a part that is used when a preferable part is not available. When an item is completely interchangeable but one part is preferable for use, the number of the preferred part shall be listed without a notation in the "USABLE ON CODE" entry and all alternate part numbers shall be listed with an asterisk (*) in the "USABLE IN CODE" entry.
When an item is completely interchangeable on certain end items, but one part number is preferable for use, the "USABLE ON CODE" entry will carry the end item identification, with or without an asterisk (*), as applicable. d. Equivalent parts. An equivalent part is defined as a part that is used interchangeably with one or more parts, none of which are preferable over the other. All equivalent part numbers shall be listed with an asterisk (*) in the "USABLE ON CODE" entry. When a part is interchangeable only on certain end items the "USABLE ON CODE" entry will carry the end item identification in addition to the required asterisk (*). 5.3.11.1.6 SM&R code.
The source, maintenance and recoverability (SM&R) code for every part for which one has been approved by the Government shall be listed as an entry under a heading "SM&R CODE." 5.3.11.1.7 Work unit code (WUC). When the equipment, assembly, subassembly, or component part has been assigned a WUC, the WUC shall be listed under this entry. 27