Machinery's Handbook, 31st Edition
Numbering Systems 395 compositions in the martensitic series; some are modified to improve machinability and others have small additions of nickel or other elements to improve the mechanical properties or their response to heat treatment. Still others have greatly increased carbon content, in the tool steel range, and are hardenable to the highest levels of all the stainless steels. The martensitic grades are excellent for service in mild environments, such as the atmosphere, freshwater, steam, and weak acids, but are not resistant to severely corrosive solutions. Numbering Systems for Metals and Alloys.— Several different numbering systems have been developed for metals and alloys by various trade associations, professional engineering societies, standards organizations, and private industries for their own use. The numerical code used to identify the metal or alloy may or may not be related to a specification, which is a statement of the technical and commercial requirements that the product must meet. Numbering systems in use include those developed by the Amer - ican Iron and Steel Institute (AISI), Society of Automotive Engineers (SAE), Ameri - can Society for Testing and Materials (ASTM), American National Standards Institute (ANSI), Steel Founders Society of America, American Society of Mechanical Engineers (ASME), American Welding Society (AWS), Aluminum Association, Copper Develop - ment Association, US Department of Defense (Military Specifications), and the General Accounting Office (Federal Specifications). The Unified Numbering System (UNS) was developed through a joint effort of the ASTM and the SAE to provide a means of correlating the different numbering systems for metals and alloys that have a commercial standing. This system avoids the confusion caused when more than one identification number is used to specify the same material, or when the same number is assigned to two entirely different materials. It is important to understand that a UNS number is not a specification; it is an identification number for metals and alloys for which detailed specifications are provided elsewhere. UNS numbers are shown in Table 1 ; each number consists of a letter prefix followed by five digits. In some, the letter is suggestive of the family of metals identified by the series, such as A for aluminum and C for copper. Whenever possible, the numbers in the UNS groups contain numbering sequences taken directly from other systems to facilitate identification of the material; e.g., the corresponding UNS number for AISI 1020 steel is G10200. The UNS numbers corresponding to the commonly used AISI-SAE numbers that are used to iden- tify plain carbon, alloy, and tool steels are given in Table 2. Table 1. Unified Numbering System (UNS) for Metals and Alloys UNS Series Metal A00001 to A99999 Aluminum and aluminum alloys C00001 to C99999 Copper and copper alloys D00001 to D99999 Specified mechanical property steels E00001 to E99999 Rare earth and rare earthlike metals and alloys F00001 to F99999 Cast irons G00001 to G99999 AISI and SAE carbon and alloy steels (except tool steels) H00001 to H99999 AISI and SAE H-steels J00001 to J99999 Cast steels (except tool steels) K00001 to K99999 Miscellaneous steels and ferrous alloys L00001 to L99999 Low-melting metals and alloys M00001 to M99999 Miscellaneous nonferrous metals and alloys N00001 to N99999 Nickel and nickel alloys P00001 to P99999 Precious metals and alloys R00001 to R99999 Reactive and refractory metals and alloys S00001 to S99999 Heat and corrosion resistant (stainless) steels T00001 to T99999 Tool steels, wrought and cast W00001 to W99999 Welding filler metals Z00001 to Z99999 Zinc and zinc alloys
Copyright 2020, Industrial Press, Inc.
ebooks.industrialpress.com
Made with FlippingBook - Share PDF online