This post includes a flange bolt dimension table in addition to my discussion of stud and bolt sizes used in plumbing. The diameter and length of the stud and bolt are covered by the ASME B16.5 and B16.47 flange standards. A bolt and stud will be utilized to attach the flanges.
The dimension chart’s nomenclature is displayed in the figure below. Class 150 Pipe Flange Bolt Charts Size in Inch Size in mm No of Bolts Bolt Size UNC RF Stud Length ISO Stud Size Machine Bolt Length Class 150 Flange 1/2 15 4 1/2 55 M14 50 3/4 20 4 1/2 65 M14 50 1 25 4 1/2 65 M14 55 1 1/4 32 4 1/2 70 M14 55 1 1/2 40 4 1/2 70 M14 65 2 50 4 5/8 85 M16 70 2 1/2 65 4 5/8 90 M16 75 3 80 4 5/8 90 M16 75 3 1/2 90 8 5/8 90 M16 75 4 100 8 5/8 90 M16 75 5 125 8 3/4 95 M20 85 6 150 8 3/4 100 M20 85 8 200 8 3/4 110 M20 90 10 250 12 7/8 115 M24 100 12 300 12 7/8 120 M24 100 14 350 12 1 135 M27 115 16 400 16 1 135 M27 115 18 450 16 1 1/8 145 M30 125 20 500 20 1 1/8 160 M30 140 24 600 20 1 1/4 170 M33 150
Class 300 Flange Bolt Charts Size in Inch Size in mm No of Bolts Bolt Size UNC RF Stud Length ISO Stud Size Machine Bolt Length Class 300 Flange 1/2 15 4 1/2 65 M14 55 3/4 20 4 5/8 75 M16 65 1 25 4 5/8 75 M16 65 1 1/4 32 4 5/8 85 M16 70 1 1/2 40 4 3/4 90 M20 75 2 50 8 5/8 90 M16 75 2 1/2 65 8 3/4 100 M20 85 3 80 8 3/4 110 M20 90 3 1/2 90 8 3/4 110 M20 95 4 100 8 3/4 115 M20 95 5 125 8 3/4 120 M20 110 6 150 12 3/4 120 M20 110 8 200 12 7/8 140 M24 120 10 250 16 1 160 M27 140 12 300 16 1 1/8 170 M30 145 14 350 20 1 1/8 180 M30 160 16 400 20 1 1/4 190 M33 165 18 450 24 1 1/4 195 M33 170 20 500 24 1 1/4 205 M33 185 24 600 24 1 1/2 230 M39 205
Class 400 Flange Bolt and Stud Dimension Chart Size in Inch Size in mm No of Bolts Bolt Size UNC RF Stud Length ISO Stud Size Class 400 Flange 1/2 15 4 1/2 75 M14 3/4 20 4 5/8 90 M16 1 25 4 5/8 90 M16 1 1/4 32 4 5/8 95 M16 1 1/2 40 4 3/4 110 M20 2 50 8 5/8 110 M16 2 1/2 65 8 3/4 120 M20 3 80 8 3/4 125 M20 3 1/2 90 8 7/8 140 M24 4 100 8 7/8 140 M24 5 125 8 7/8 145 M24 6 150 12 7/8 150 M24 8 200 12 1 170 M27 10 250 16 1 1/8 190 M30 12 300 16 1 1/4 205 M33 14 350 20 1 1/4 210 M33 16 400 20 1 3/8 220 M36 18 450 24 1 3/8 230 M36 20 500 24 1 1/2 240 M39 24 600 24 1 3/4 265 M45
Bolt Charts for Class # 600 Flanges Size in Inch Size in mm No of Bolts Bolt Size UNC RF Stud Length ISO Stud Size Class 600 Flange 1/2 15 4 1/2 75 M14 3/4 20 4 5/8 90 M16 1 25 4 5/8 90 M16 1 1/4 32 4 5/8 95 M16 1 1/2 40 4 3/4 110 M20 2 50 8 5/8 110 M16 2 1/2 65 8 3/4 120 M20 3 80 8 3/4 125 M20 3 1/2 90 8 7/8 140 M24 4 100 8 7/8 145 M24 5 125 8 1 165 M27 6 150 12 1 170 M27 8 200 12 1 1/8 190 M30 10 250 16 1 1/4 215 M33 12 300 20 1 1/4 220 M33 14 350 20 1 3/8 235 M36 16 400 20 1 1/2 255 M39 18 450 20 1 5/8 275 M42 20 500 24 1 5/8 285 M42 24 600 24 1 7/8 330 M48
Class 900 Flange Bolt Charts Size in Inch Size in mm No of Bolts Bolt Size UNC RF Stud Length ISO Stud Size Class 900 Flange 1/2 15 4 3/4 110 M20 3/4 20 4 3/4 115 M20 1 25 4 7/8 125 M24 1 1/4 32 4 7/8 125 M24 1 1/2 40 4 1 140 M27 2 50 8 7/8 145 M24 2 1/2 65 8 1 160 M27 3 80 8 7/8 145 M24 4 100 8 1 1/8 170 M30 5 125 8 1 1/4 190 M33 6 150 12 1 1/8 190 M30 8 200 12 1 3/8 220 M36 10 250 16 1 3/8 235 M36 12 300 20 1 3/8 255 M36 14 350 20 1 1/2 275 M39 16 400 20 1 5/8 285 M42 18 450 20 1 7/8 325 M48 20 500 20 2 350 M52 24 600 20 2 1/2 440 M64
Class 1500 Bolt and stud Charts Size in Inch Size in mm No of Bolts Bolt Size UNC RF Stud Length ISO Stud Size Class 1500 Flange 1/2 15 4 3/4 110 M20 3/4 20 4 3/4 115 M20 1 25 4 7/8 125 M24 1 1/4 32 4 7/8 125 M24 1 1/2 40 4 1 140 M27 2 50 8 7/8 145 M24 2 1/2 65 8 1 160 M27 3 80 8 1 1/8 180 M30 4 100 8 1 1/4 195 M33 5 125 8 1 1/2 250 M39 6 150 12 1 3/8 260 M36 8 200 12 1 5/8 290 M42 10 250 12 1 7/8 335 M48 12 300 16 2 375 M52 14 350 16 2 1/4 405 M56 16 400 16 2 1/2 445 M64 18 450 16 2 3/4 495 M72 20 500 16 3 540 M76 24 600 16 3 1/2 615 M90
Class 2500 Stud and Bolt Dimensions Charts Size in Inch Size in mm No of Bolts Bolt Size UNC RF Stud Length ISO Stud Size Class 2500 Flange 1/2 15 4 3/4 120 M20 3/4 20 4 3/4 125 M20 1 25 4 7/8 140 M24 1 1/4 32 4 1 150 M27 1 1/2 40 4 1 1/8 170 M30 2 50 8 1 180 M27 2 1/2 65 8 1 1/8 195 M30 3 80 8 1 1/4 220 M33 4 100 8 1 1/2 255 M39 5 125 8 1 3/4 300 M45 6 150 8 2 345 M52 8 200 12 2 380 M52 10 250 12 2 1/2 490 M64 12 300 12 2 3/4 540 M72
