Tapping & Drilling Chart

You are here: Home»Useful Guides and Charts» Tapping & Drilling Chart
Download pdf version (82 Kb)

Jump to BSW & BSF Threads
Jump to UNC & UNF Threads
Jump to Metric Threads


BRITISH STANDARD FINE THREAD & BRITISH STANDARD WHITWORTH THREAD

Nominal Dia BSW BSF
Threads per Inch Tapping Drill Threads per Inch Tapping Drill
3/16 " 24 3.7mm 32 5/32 "
1/4 " 20 5.1mm 26 5.4mm
5/16 " 18 6.5mm 22 6.8mm
3/8 " 16 5/16 " 20 21/64 "
7/16 " 14 9.3mm 18 9.7mm
1/2 " 12 27/64 " 16 7/16 "
9/16 " 12 31/64 " 16 1/2 "
5/8 " 11 17/32 " 14 14mm
3/4 " 10 16.5mm 12 43/64 "
7/8 " 9 49/64 " 11 20mm
1 " 8 7/8 " 10 29/32 "
1.1/8 " 7 63/64 " 9 1 1/64 "
1.1/4 " 7 1 7/64 " 9 1 27/28 "
1.3/8 " 6 1 13/64 " 8 1 1/4 "
1.1/2 " 6 1 21/64 " 8 1 3/8 "
1.3/4 " 5 1 35/64 " 7 1 39/64 "
2 " 4.5 45mm 7 1 55/64 "

UNIFIED COARSE THREAD & UNIFIED FINE THREAD

Nominal Dia UNC UNF
Threads per Inch Tapping Drill Threads per Inch Tapping Drill
3/16 " 24 3.9 32 4.1mm
1/4 " 20 13/64 " 28 7/32 "
5/16 " 18 6.6mm 24 7.0mm
3/8 " 16 8.0mm 24 8.5mm
7/16 " 14 9.4mm 20 25/64 "
1/2 " 13 10.0mm 20 29/64 "
9/16 " 12 31/64 " 18 13
5/8 " 11 35/64 " 18 14.5mm
3/4 " 10 21/32 " 16 17.5mm
7/8 " 9 49/64 " 14 20.5mm
1 " 8 57/64 " 12 59/64 "
1.1/8 " 7 63/64 " 12 1 3/64 "
1.1/4 " 7 1 7/64 " 12 1 11/64 "
1.3/8 " 6 1 7/32 " 12 33.0mm
1.1/2 " 6 1 11/32 " 12 1 27/64 "
1.3/4 " 5 1 9/16 "    
2 " 4.5 1 51/64 "    

METRIC THREAD

Metric Isometric Pitch
Nominal Dia Tapping Drill Coarse Fine
M5 4.2mm 0.8 0.5
M6 5.1mm 1 0.75
M8 6.8mm 1.25 1
M10 8.6mm 1.5 1.25
M12 10.4mm 1.75 1.25
M14 12.1mm 2 1.5
M16 14.0mm 2 1.5
M18 15.5mm 2.5 1.5
M20 17.5mm 2.5 1.5
M22 19.5mm 2.5 1.5
M24 21.0mm 3 2
M27 24.0mm 3  
M30 36.5mm 3.5  
M36 32.0mm 4  
M39   4  
M42   4.5  
M48   5  
Back to Top
Previous Page