1.1 This specification covers seamless stainless tubing for use in mechanical applications where corrosion-resistant or high-temperature strength is needed. The grades covered are listed in Table 1, Table 2, and Table 3. 1.2 This specification covers seamless cold-finished mechanical tubing and seamless hot-finished mechanical tubing in sizes up to 12 3/4 in. [325 mm] in outside nominal diameter (for round tubing) with wall thicknesses as required. 1.3 Tubes shall be furnished in one of the following shapes, as specified by the purchaser: round, square, rectangular, or special. 1.4 Optional supplementary requirements are provided and when desired, shall be stated in the order. 1.5 The values stated in inch-pound units are to be regarded as the standard. Within the text, the SI units are shown in square brackets. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. TABLE 1 Chemical Requirements of Austenitic Stainless Steels Grade Composition, % Carbon Manga- nese, max Phos- pho- rus, max Sul- fur, max Silicon, max Nickel Chromium Molybdenum Titanium Columbium plus Tantalum Selenium MT 302 0.08 to 0.20 2.00 0.040 0.030 1.00 8.0 - 10.0 17.0 - 19.0 ... ... ... ... MT 303 0.15 max 2.00 0.20 0.15 min 1.00 8.0 - 10.0 17.0 - 19.0 ... ... ... ... MT 303Se 0.15 max 2.00 0.040 0.040 1.00 8.0 - 11.0 17.0 - 19.0 ... ... ... 0.12 - 0.2 MT 304 0.08 max 2.00 0.040 0.030 1.00 8.0 - 11.0 18.0 - 20.0 ... ... ... ... MT 304L 0.035 max A 2.00 0.040 0.030 1.00 8.0 - 13.0 18.0 - 20.0 ... ... ... ... MT 305 0.12 2.00 0.040 0.030 1.00 10.0 - 13.0 17.0 - 19.0 ... ... ... ... MT 309S 0.08 max 2.00 0.040 0.030 1.00 12.0 - 15.0 22.0 - 24.0 ... ... ... ... MT 310S 0.08 max 2.00 0.040 0.030 1.00 19.0 - 22.0 24.0 - 26.0 ... ... ... ... MT 316 0.08 max 2.00 0.040 0.030 1.00 11.0 - 14.0 16.0 - 18.0 2.0 - 3.0 ... ... ... MT 316L 0.035 max A 2.00 0.040 0.030 1.00 10.0 - 15.0 16.0 - 18.0 2.0 - 3.0 ... ... ... MT 317 0.08 max 2.00 0.040 0.030 1.00 11.0 - 14.0 18.0 - 20.0 3.0 - 4.0 ... ... ... MT 321 0.08 max 2.00 0.040 0.030 1.00 9.0 - 13.0 17.0 - 20.0 ... B ... ... MT 347 0.08 max 2.00 0.040 0.030 1.00 9.0 - 13.0 17.0 - 20.0 ... ... C ... A For small diameter or thin wall tubing or both, where many drawing passes are required, a maximum of 0.040 % carbon is necessary in grades MT-304L and MT-316L. Small outside diameter tubes are defined as those under a 0.500 in. [12.7 mm] outside diameter and light-wall tubes as those under a 0.049 in. [1.2 mm] average wall thickness (0.044 in. [1.1 mm] min wall thickness). B The titanium content shall be not less than five times the carbon content and not more than 0.60 %. C The columbium plus tantalum content shall be not less than ten times the carbon content and not more than 1.00 %. TABLE 2 Chemical Requirements of Ferritic and Martensitic Stainless Steels Grade Composition, % Carbon, max Manga- nese, max Phos- phorus, max Sulfur, max Silicon, max Nickel Chromium Molyb- denum Aluminum Copper Nitrogen Selenium Martensitic MT 403 ...