Thread Identification (British)

Basic Major DiameterNominal Diameter (mm)Threads Per Inch
InchmmBABSWBSFBSPBSPT
.01180.30      
.01180.30      
.01380.35      
.01460.37 22254    
.01570.40      
.01650.42 21231    
.01770.45      
.01890.48 20211 3/4    
.01970.50      
.02090.53      
.02130.54 19181 1/2    
.02170.55      
.02360.60      
.02440.62 18169 1/4    
.02760.70 17149 1/2    
.03110.79 16133 3/4    
.03150.80      
.03400.86      
.03540.90 15121    
.03941.00 14110 1/2    
.04331.10      
.04701.19      
.04721.20 13101 1/2    
.05121.30 1290 3/4    
.05511.40      
.05911.50 1182    
.06001.52      
.06291.60      
.06691.701072 1/2    
.07091.80      
.07301.85      
.07481.90 965    
.07872.00      
.08602.18      
.08662.20 859    
.09062.30      
.09842.50 753    
.09902.51      
.10242.60      
.11022.80 648    
.11202.84      
.11813.00      
.12503.18 1/8 40   
.12603.20 543    
.13803.50      
.14173.60 438 1/2    
.15754.00      
.16144.10 334 3/4    
.16404.17      
.17724.50      
.18504.70 231 3/4    
.18754.76 3/16 2432  
.19004.83      
.19695.00      
.20875.30 128 1/4    
.21605.49      
.21655.50      
.21885.56 7/32  28  
.23626.00 025 1/2    
.25006.35 1/4 2026  
.27567.00      
.28127.14 9/32  26  
.31257.94 5/16 1822  
.31257.94      
.31508.00      
.35439.00      
.37509.53 3/8 1620 28
.38309.73 1/8   28 
.393710.00      
.405010.29      
.433111.00      
.437511.11 7/16 1418  
.472412.00      
.500012.70 1/2 1216  
.518013.16      
.540013.72      
.551214.00      
.562514.29 9/16 1216  
.625015.88 5/8 1114  
.629916.00      
.656016.66 3/8   1919
.675017.15      
.687517.46 11/16 1114  
.708718.00      
.750019.053/4 1012  
.787420.00      
.812520.64 13/16  12  
.825020.96 1/2    14
.840021.34    14 
.866122.00      
.875022.23 7/8 911  
.902022.91 5/8   1414
.937523.81      
.944924.00      
1.000025.40 1 810  
1.023626.00      
1.04101126.44 3/4   1414
1.050026.67      
1.062526.99      
1.063027.00      
1.125028.581 1/8  79  
1.181130.00      
1.187530.16      
1.189030.20 7/8   1414
1.250031.75 1 1/4 79  
1.259832.00      
1.299233.00      
1.309033.25 1   1111
1.312533.34      
1.315033.40      
1.375034.93 1 3/8  8  
1.378035.00      
1.417336.00      
1.437536.51      
1.492037.90 1 1/8   11 
1.496138.00      
1.500038.101 1/2 68  
1.535439.00      
1.562539.69      
1.574840.00      
1.625041.281 5/8  8  
1.650041.91 1 1/4   1111
1.653542.00      
1.660042.16      
1.687542.86      
1.745044.32 1 3/8   11 
BA-British Association
BSW-British Standard Whitworth
BSF-British Standard Fine
BSP-British Standard Pipe
BSPT-British Standard Pipe Tapered

*All information is strictly informative

Back
Home
Top