API Flanges Dimensions

API Flange Dimensions

Nom. size No. of holes Outside diam. of flange Diam. of hub Hub diam. top Diam. of bolt hole Diam. of bolt Thick. of flange Length through hub Diam. of bolt circle Raised face diam. Fillet radius min.
O X A C Y R r1
in. 26″ 36 30.94 26.94 26.06 0.88 3/4″ 1.62 3.5 29.31 28 0.38
mm. 785.9 684.3 661.9 22.4 19.1 41.1 88.9 744.5 711.2 9.7
in. 28″ 40 32.94 28.94 28.06 0.88 3/4″ 1.75 3.75 31.31 30 0.38
mm. 836.7 735.1 712.7 22.4 19.1 44.5 95.3 795.3 762 9.7
in. 30″ 44 34.94 31 30.06 0.88 3/4″ 1.75 3.94 33.31 32 0.38
mm. 887.5 787.4 763.5 22.4 19.1 44.5 100.1 846.1 812.8 9.7
in. 32″ 48 37.06 33.06 32.06 0.88 3/4″ 1.81 4.25 35.44 34 0.38
mm. 941.3 839.7 814.3 22.4 19.1 46 108 900.2 863.6 9.7
in. 34″ 40 39.56 35.12 34.06 1 7/8″ 1.94 4.34 37.69 36.25 0.38
mm. 1004.8 892 865.1 25.4 22.2 49.3 110.2 957.3 920.8 9.7
in. 36″ 44 41.62 37.19 36.06 1 7/8″ 2.06 4.62 39.75 38.25 0.38
mm. 1057.1 944.6 915.9 25.4 22.2 52.3 117.3 1009.7 971.6 9.7
in. 38″ 40 44.25 39.12 38.12 1.12 1″ 2.12 4.88 42.12 40.25 0.38
mm. 1124 993.6 968.2 28.4 25.4 53.8 124 1069.8 1022.4 9.7
in. 40″ 44 46.25 41.31 40.12 1.12 1″ 2.19 5.06 44.12 42.5 0.38
mm. 1174.8 1049.3 1019 28.4 25.4 55.6 128.5 1120.6 1079.5 9.7
in. 42″ 48 48.25 43.38 42.12 1.12 1″ 2.31 5.25 46.12 44.5 0.44
mm. 1225.6 1101.9 1069.8 28.4 25.4 58.7 133.4 1171.4 1130.3 11.2
in. 44″ 52 50.25 45.38 44.12 1.12 1″ 2.38 5.38 48.12 46.5 0.44
mm. 1276.4 1152.7 1120.6 28.4 25.4 60.5 136.7 1222.2 1181.1 11.2
in. 46″ 40 52.81 47.44 46.12 1.25 1 1/8″ 2.44 5.69 50.56 48.62 0.44
mm. 1341.4 1205 1171.4 31.8 28.6 62 144.5 1284.2 1234.9 11.2
in. 48″ 44 54.81 49.5 48.12 1.25 1 1/8″ 2.56 5.88 52.56 50.75 0.44
mm. 1392.2 1257.3 1222.2 31.8 28.6 65 149.4 1335 1289.1 11.2
in. 50″ 48 56.81 51.5 50.12 1.25 1 1/8″ 2.69 6.06 54.56 52.75 0.44
mm. 1443 1308.1 1273 31.8 28.6 68.3 153.9 1385.8 1339.9 11.2
in. 52″ 52 58.81 53.56 52.12 1.25 1 1/8″ 2.75 6.19 56.56 54.75 0.44
mm. 1493.8 1360.4 1323.8 31.8 28.6 69.9 157.2 1436.6 1390.7 11.2
in. 54″ 56 61 55.62 54.12 1.25 1 1/8″ 2.81 6.38 58.75 56.75 0.44
mm. 1549.4 1412.7 1374.6 31.8 28.6 71.4 162.1 1492.3 1441.5 11.2
in. 56″ 60 63 57.69 56.12 1.25 1 1/8″ 2.88 6.56 60.75 58.75 0.56
mm. 1600.2 1465.3 1425.4 31.8 28.6 73.2 166.6 1543.1 1492.3 14.2
in. 58″ 48 65.94 59.69 58.12 1.38 1 1/4″ 2.94 6.88 63.44 60.75 0.56
mm. 1674.9 1516.1 1476.2 35.1 31.8 74.7 174.8 1611.4 1543.1 14.2
in. 60″ 52 67.94 61.81 60.12 1.38 1 1/4″ 3 7.06 65.44 63 0.56
mm. 1725.7 1570 1527 35.1 31.8 76.2 179.3 1662.2 1600.2 14.2