Includes API Spec 6A current, discontinued, and Obsolete flanges
| API 6A Flange Size | Weld Neck Weight Lbs. | Blind Weight Lbs. | Number of Stud Bolts Per Set | Weight For 1 Set of All Thread Stud Bolts with 2 Nuts Each Lbs. | Weight for 1 Set of Tap End Studs with 1 Nut Each Lbs. | Gasket Number | Weight Lbs. |
| 1-5/8-10M / 2″-2900 * | 29.6 | 28.5 | 8 | 13.3 | 8.2 | R-85 RX-85 | 0.88 1.18 |
| 1-11/16-10M * | 19.5 | 24.7 | 8 | 7.7 | 4.7 | BX-150 | 0.29 |
| 1-11/16-15M * | 24.0 | 27.6 | 8 | 7.9 | 4.8 | BX-150 | 0.29 |
| 1-25/32-10M 2-1/2″ 2900 * | 44.4 | 43.1 | 8 | 19.5 | 12.4 | R-86 RX-86 | 1.44 1.82 |
| 1-13/16-2M * | 9.8 | 9.4 | 4 | 3.5 | 2.3 | R-20 RX-20 | 0.37 0.53 |
| 1-13/16-3M * | 16.0 | 15.6 | 4 | 7.9 | 5.1 | R-20 RX-20 | 0.37 0.53 |
| 1-13/16-5M * | 16.3 | 15.6 | 4 | 7.9 | 5.1 | R-20 RX-20 | 0.37 0.53 |
| 1-13/16-10M | 20.8 | 24.6 | 8 | 7.7 | 4.7 | BX-151 | 0.33 |
| 1-13/16-15M | 27.5 | 31.5 | 8 | 11.6 | 7.1 | BX-151 | 0.33 |
| 1-13/16-20M | 62.3 | 66.2 | 8 | 18.4 | 11.1 | BX-151 | 0.33 |
| 1-13/16-30M * | 110.4 | 114.1 | 8 | 35.0 | 21.4 | BX-151 | 0.33 |
| 2″ 960 * | 11.7 | 11.7 | 8 | 4.7 | 3.0 | R-23 RX-23 | 0.76 1.18 |
| 2-1/16-2M | 12.0 | 11.7 | 8 | 4.7 | 3.0 | R-23 RX-23 | 0.76 1.18 |
| 2-1/16-3M | 28.9 | 27.2 | 8 | 12.2 | 7.7 | R-24 RX-24 | 0.87 1.36 |
| 2-1/16-5M | 29.6 | 27.2 | 8 | 12.2 | 7.7 | R-24 RX-24 | 0.87 1.36 |
| 2-1/16-10M / 3″ 2900 * | 62.3 | 61.2 | 8 | 27.8 | 17.0 | R-87 RX-87 | 1.59 2.01 |
| 2-1/16-10M | 25.3 | 30.4 | 8 | 7.7 | 4.8 | BX-152 | 0.41 |
| 2-1/16-15M | 36.1 | 41.7 | 8 | 12.2 | 7.4 | BX-152 | 0.41 |
| 2-1/16-20M | 87.2 | 92.8 | 8 | 25.9 | 15.8 | BX-152 | 0.41 |
| 2-1/16 30M * | 126.8 | 131.9 | 8 | 36.8 | 22.3 | BX-152 | 0.41 |
| 2-1/2″ 960 * | 16.5 | 16.9 | 8 | 7.7 | 4.9 | R-26 RX-26 | 0.93 1.44 |
| 2-9/16-2M | 16.9 | 16.9 | 8 | 7.7 | 4.9 | R-26 RX-26 | 0.93 1.44 |
| 2-9/16-3M | 39.4 | 37.3 | 8 | 17.3 | 11.1 | R-27 RX-27 | 1.00 1.53 |
| 2-9/16-5M | 40.1 | 37.3 | 8 | 17.3 | 11.1 | R-27 RX-27 | 1.00 1.53 |
| 2-9/16-10M / 3-1/2″ 2900 * | 88.8 | 89.9 | 8 | 37.4 | 23.2 | R-89 RX-89 | 2.49 3.03 |
| 2-9/16-10M | 39.0 | 47.5 | 8 | 12.2 | 7.4 | BX-153 | 0.62 |
| 2-9/16-15M | 52.0 | 60.7 | 8 | 17.6 | 10.7 | BX-153 | 0.62 |
| 2-9/16-20M | 122.7 | 132.1 | 8 | 35.6 | 21.4 | BX-153 | 0.62 |
| 2-9/16-30M * | 175.8 | 185.4 | 12 | 57.9 | 34.4 | BX-153 | 0.62 |
| 3″ 960 * | 21.3 | 24.2 | 8 | 7.9 | 5.0 | R-31 RX-31 | 1.14 1.77 |
| 3-1/8-2M | 21.8 | 22.7 | 8 | 7.9 | 5.0 | R-31 RX-31 | 1.14 1.77 |
| 3-1/8-3M | 35.8 | 34.9 | 8 | 12.2 | 7.7 | R-31 RX-31 | 1.14 1.77 |
| 3-1/8-5M | 52.4 | 49.6 | 8 | 24.4 | 15.6 | R-35 RX-35 | 1.25 1.95 |
| 3-1/8-10M 4″ 2900 * | 112.9 | 113.9 | 8 | 49.0 | 30.4 | R-88 RX-88 | 2.70 3.26 |
| 3-1/16-10M | 60.1 | 73.2 | 8 | 17.6 | 10.9 | BX-154 | 0.85 |
| 3-1/16-15M | 75.7 | 89.1 | 8 | 24.9 | 15.4 | BX-154 | 0.85 |
| 3-1/16-20M | 157.7 | 172.5 | 8 | 46.7 | 28.2 | BX-154 | 0.85 |
| 3-1/16-30M * | 256.1 | 270.5 | 12 | 76.8 | 45.6 | BX-154 | 0.85 |
| 4″ 960 * | 33.1 | 36.4 | 8 | 11.9 | 7.5 | R-37 RX-37 | 1.37 2.13 |
| 4-1/16-2M | 44.4 | 45.7 | 8 | 12.2 | 7.7 | R-37 RX-37 | 1.37 2.13 |
| 4-1/16-3M | 57.9 | 57.6 | 8 | 23.9 | 15.4 | R-37 RX-37 | 1.37 2.13 |
| 4-1/16-5M | 78.4 | 76.2 | 8 | 33.2 | 21.1 | R-39 RX-39 | 1.49 2.31 |
| 4-1/16-10M / 5″ 2900 * | 167.9 | 169.1 | 8 | 80.9 | 50.5 | R-90 RX-90 | 4.51 6.84 |
| 4-1/16-10M | 99.1 | 125.1 | 8 | 25.9 | 15.8 | BX-155 | 1.44 |
| 4-1/16-15M | 142.6 | 169.8 | 8 | 45.2 | 27.4 | BX-155 | 1.44 |
| 4-1/16-20M | 298.5 | 328.5 | 8 | 94.7 | 57.7 | BX-155 | 1.44 |
| 4-1/16-30M * | 500.6 | 529.3 | 12 | 154.5 | 93.0 | BX-155 | 1.44 |
| 5″ 960 * | 42.6 | 47.9 | 8 | 12.2 | 7.7 | R-41 RX-41 | 1.66 2.58 |
| 5-1/8-2M | 75.1 | 76.5 | 8 | 17.6 | 11.3 | R-41 RX-41 | 1.66 2.58 |
| 5-1/8-3M | 92.1 | 93.5 | 8 | 32.5 | 20.8 | R-41 RX-41 | 1.66 2.58 |
| 5-1/8-5M | 145.7 | 143.8 | 8 | 58.4 | 36.8 | R-44 RX-44 | 1.78 2.76 |
| 5-1/8-10M | 140.3 | 134.5 | 12 | 41.0 | 24.5 | BX-169 | 1.74 |
| 5-1/8-15M | 231.1 | 220.1 | 12 | 93.0 | 56.5 | BX-169 | 1.74 |
| 6″ 960 * | 55.2 | 65.2 | 12 | 18.7 | 11.7 | R-45 RX-45 | 1.94 3.01 |
| 7-1/16-2M | 88.2 | 92.0 | 12 | 27.0 | 17.2 | R-45 RX-45 | 1.94 3.01 |
| 7-1/16-3M | 119.0 | 119.5 | 12 | 38.8 | 24.1 | R-45 RX-45 | 1.94 3.01 |
| 7-1/16-5M | 176.3 | 176.6 | 12 | 74.5 | 45.6 | R-46 RX-46 | 2.38 3.67 |
| 7-1/16-10M / 10″ 2900 * | 480.1 | 480.0 | 12 | 235.9 | 144.9 | R-91 RX-91 | 15.64 17.16 |
| 7-1/16-10M | 319.8 | 315.2 | 12 | 94.3 | 57.2 | BX-156 | 4.04 |
| 7-1/16-15M | 405.0 | 390.3 | 16 | 134.7 | 80.7 | BX-156 | 4.04 |
| 7-1/16-20M | 949.1 | 893.9 | 16 | 327.5 | 193.2 | BX-156 | 4.04 |
| 7-1/16-30M * | 1779.4 | 1888.1 | 16 | 611.4 | 362.8 | BX-156 | 4.04 |
| 8″ 960 * | 85.4 | 106.7 | 12 | 27.0 | 17.2 | R-49 RX-49 | 2.47 3.85 |
| 9-2M | 130.2 | 146.8 | 12 | 38.8 | 24.1 | R-49 RX-49 | 2.47 3.85 |
| 9-3M | 204.5 | 204.8 | 12 | 66.8 | 42.3 | R-49 RX-49 | 2.47 3.85 |
| 9-5M | 306.9 | 299.8 | 12 | 118.1 | 73.3 | R-50 RX-50 | 4.42 6.35 |
| 9-10M | 488.1 | 498.5 | 16 | 138.3 | 81.6 | BX-157 | 6.40 |
| 9-15M | 842.1 | 807.4 | 16 | 259.7 | 154.1 | BX-157 | 6.40 |
| 9-20M | 1738.0 | 1651.8 | 16 | 632.1 | 375.8 | BX-157 | 6.40 |
| 10″ 960 * | 117.8 | 158.9 | 16 | 50.8 | 32.1 | R-53 RX-53 | 2.97 4.63 |
| 11-2M | 248.2 | 240.1 | 16 | 69.9 | 44.0 | R-53 RX-53 | 2.97 4.63 |
| 11-3M | 302.0 | 300.8 | 16 | 92.0 | 57.9 | R-53 RX-53 | 2.97 4.63 |
| 11-5M | 533.5 | 512.3 | 12 | 179.8 | 111.3 | R-54 RX-54 | 5.30 7.63 |
| 11-10M | 772.5 | 809.3 | 16 | 215.9 | 128.9 | BX-158 | 9.36 |
| 11-15M | 1949.9 | 1619.4 | 20 | 438.0 | 255.7 | BX-158 | 9.36 |
| 11-20M | 2235.7 | 2198.3 | 16 | 836.6 | 497.3 | BX-158 | 9.36 |
| 12″ 960 * | 169.2 | 231.5 | 16 | 67.5 | 42.8 | R-57 RX-57 | 3.49 5.44 |
| 13-5/8-2M | *** | 302.3 | 20 | 88.9 | 55.8 | R-57 RX-57 | 3.49 5.44 |
| 13-5/8-3M | *** | 419.1 | 20 | 120.5 | 75.1 | R-57 RX-57 | 3.49 5.44 |
| 13-5/8-5M / 14″ 1500 * | *** | 1033.4 | 16 | 430.3 | 265.2 | R-63 RX-63 | 16.12 26.47 |
| 13-5/8-5M | 616.7 | 743.5 | 16 | 159.6 | 96.7 | BX-160 | 6.64 |
| 13-5/8-10M | 1236.9 | 1329.3 | 20 | 349.6 | 205.1 | BX-159 | 14.08 |
| 13-5/8-15M | 2008.8 | 2098.0 | 20 | 611.0 | 360.2 | BX-159 | 14.08 |
| 13-5/8-20M | 5075.1 | 5008.3 | 20 | 1504.7 | 875.2 | BX-159 | 14.08 |
| 16″ 960 * | 294.6 | 393.4 | 20 | 111.3 | 70.5 | R-65 RX-65 | 4.31 6.71 |
| 16-3/4-2M | *** | 515.0 | 20 | 148.3 | 93.1 | R-65 RX-65 | 4.31 6.71 |
| 16-3/4-3M | *** | 636.8 | 20 | 194.2 | 120.9 | R-66 RX-66 | 7.69 10.48 |
| 16-3/4-5M | 810.2 | 1085.8 | 16 | 245.5 | 147.0 | BX-162 | 4.96 |
| 16-3/4-10M | 1464.5 | 1813.1 | 24 | 419.6 | 246.2 | BX-162 | 4.96 |
| 17-3/4-2M * | *** | 649.2 | 20 | 155.0 | 97.6 | R-69 RX-69 | 4.89 7.62 |
| 17-3/4-3M * | *** | 904.0 | 20 | 296.1 | 183.7 | R-70 RX-70 | 11.79 20.16 |
| 18-3/4-5M | 1616.6 | 1871.9 | 20 | 409.4 | 243.5 | BX-163 | 14.70 |
| 18-3/4-10M | 2999.2 | 3256.1 | 24 | 770.7 | 451.1 | BX-164 | 21.35 |
| 18-3/4-15M | 4357.6 | 4628.2 | 20 | 1391.3 | 823.2 | BX-164 | 21.35 |
| 20″ 960 * | 440.0 | 623.5 | 24 | 175.3 | 110.4 | R-73 RX-73 | 6.59 11.65 |
| 21-1/4-2M | *** | 842.5 | 24 | 233.1 | 145.1 | R-73 RX-73 | 6.59 11.65 |
| 20-3/4-3M | *** | 1131.0 | 20 | 364.5 | 225.1 | R-74 RX-74 | 12.91 22.05 |
| 21-1/4-5M | 2086.4 | 2463.2 | 24 | 515.8 | 302.0 | BX-165 | 18.74 |
| 21-1/4-10M | 3877.9 | 4304.1 | 24 | 1041.6 | 606.5 | BX-166 | 27.17 |
| 26-3/4-2M | 1435.1 | 1931.0 | 20 | 257.5 | 153.5 | BX-167 | 17.85 |
| 26-3/4-3M | 2088.0 | 2566.0 | 24 | 486.4 | 287.3 | BX-168 | 22.23 |
| 30″ 300# MSS ** | 1055.9 | 1694.6 | 28 | 347.6 | 214.8 | R-95 | 18.70 |
| 30″ 600# MSS ** | 1426.2 | 2516.7 | 28 | 527.5 | 323.7 | R-95 | 18.70 |
| 30″ 900# MSS ** | 2323.4 | 3816.8 | 20 | 1155.4 | 719.3 | R-102 | 51.49 |
| 30-2M | 1691.4 | 2454.2 | 32 | 348.8 | 208.2 | BX-303 | 27.57 |
| 30-3M | 2457.8 | 3239.9 | 32 | 559.4 | 328.1 | BX-303 | 27.57 |
**MSS flanges used primarily on Diverter BOP’s of 500 psi and 1,000 psi working pressure.
***API has not specified a weld neck for 6B flanges larger than 11” 5M and WOODCO USA has no entry on this table for these flanges.
API has specified weld necks for many 6BX flanges, and not done so for many others, but API has provided the basis for determining the dimensions of a 6BX integral flange that the manufacturer may attach to a body by welding. WOODCO USA has used API specified dimensions to calculate all the flange weights shown on this table. All weights rounded to the nearest 1/10 lb., except ring gaskets, shown in pounds with decimals to 2 places.
Various tolerances contribute to significant differences in weights. Most API 6A manufacturers that only make flanges, make 6B weld neck flanges with raised faces, while most API 6A wellhead manufacturers make all of their API 6B flanges, weld neck or otherwise, with full faces. All 6BX flanges must have a raised face, but API specifies a minimum raised face of 1/8″ height, with a maximum height equal to the ring groove depth. More recently API 6A has increased the tolerance on bolt holes, adding further variation to weight. The calculated weights for flanges shown in this table consider the flanges to have the maximum weight based on the tolerance limits specified by API. Consider all flange weights shown as approximate.
Only the weight of 3 ring gasket profiles, R (Oval), RX and BX appear on this table, consider weights for R (Octagonal), SRX and SBX as virtually the same.
