3 NACE Class - III Studs a. ASTM A193 Gr B7 is provided for non exposed service for the API flanges for NACE MR 01-75 Class III only. b. ASTM A320 Gr L7 is provided for non exposed service for the API flanges for NACE MR 01-75 Class III only. NACE Nuts a. ASTM A194 Gr 2 HM is provided for all API flange sizes and rated working pressures. Studs & Nuts for ANSI B-16.5 Flanges (Table - 2) Bolting materials for high strength bolting having an allowable stress not less than those for ASTM A193 Gr. B7 are also listed. These and other materials of comparable strength and can be used. Studs & Nuts (As per 6A & ANSI B16.5) 1.1 Brief Description Global Supply Line supplies studs and nuts to meet requirements of all API flanges as per API-6A, as well as flanges as per ANSI B16-5 and MSS-SP-44 & BS 3293. Studs & Nuts for API Flanges (Table - 1) Studs and nuts shall meet the requirements of the applicable ASTM specs unless otherwise noted. Dimension and thread pitch shall be as per ASTM A193 for studs and ASTM A194 for nuts. The mechanical properties as specified in the table. API flanges takes precedence from those required by ASTM. Yield strength shall equal or exceed the minimum shown in the table. NACE Class - 1 Studs a. UNS No. 05500 in the hot rolled and age hardened condition will have a hardness of RHRC 35 or lower and a minimum yield strength of 105000 PSI (725 MPA) for dia’s up to 2.5” and of 95000 PSI for larger sizes. b. ASTM A453 Gr 660 solution treated and age hardened will have a hardness of HRC 35 and lower and a minimum yield strength of 105,000 PSI for dia’s up to 2.5” and of 95000 PSI for larger sizes. NACE Class - II Studs a. ASTM A193 Gr B7M is provided at a minimum yield strength of 80,000 PSI for the API flanges for NACE MR 01-75 Class II only. b. ASTM A320 grade L7M is provided at a minimum yield strength of 80000 PSI for API flanges for NACE MR 01-75 Class II only. PAGE 16 STUDS & NUTS 1.2 Bolting requirements for API End Flanges - Applicable ASTM Specification Table - 1 REQUIREMENT AA, BB or CC DD, EE, FF & HH TEMPERATURE CLASSIFICATION TEMPERATURE CLASSIFICATION P, S,T or U K, L, P, S, T or U P, S,T or U K, L, P, S, T or U P, S,T or U K, L, P, S, T or U S, K, L, P, T or U NACE MR0175 CLASS NONE NONE III III II II I SIZE AND RATED WORKING PRESSURE ALL ALL ALL ALL ALL 2000 AND 3000PSI 5000PSI FLGS 2.5IN) 105 (≤2.5IN) 95 (>2.5IN) 80 80 105 (≤2.5IN) 95 (>2.5IN) HARDNESS PER NACE MR0175 NO NO NO NO YES YES YES CHARPY TESTING REQUIRED NO YES NO YES NO YES NO NUTS ASTM SPEC AND GRADES HEAVY A194 2H, 2HM 4 OR 7 A194 2H, 2HM 4 OR 7 A194 2H, 2HM 4 OR 7 A194 2H, 2HM 4 OR 7 A194 GR 2HM A194 GR 2HM A194 GR 2HM HARDNESS PER NACE MR0175 NO NO NO NO YES YES YES CHARPY TESTING REQUIRED NO NO NO NO NO NO NO