Fabrication

American Standard Pipe Dimensions

Tapping Drills

PipeTapping Drills
Size
(in)		Threads/
Inch		Nom. OD (in) Taper NPT w/ Reamer * Taper NPT w/o Reamer Straight NPS
Drill SizeEquivalents Drill SizeEquivalents Drill SizeEquivalents
(in)(mm) (in)(mm) (in)(mm)
1/16270.313 15/64"0.23445.9531 C0.24206.1468 1/4"0.25006.3500
1/8270.405 21/64"0.32818.3344 Q0.33208.4328 11/32"0.34388.7313
1/4180.540 27/64"0.421910.7156 7/16"0.437511.1125 7/16"0.437511.1125
3/8180.675 9/16"0.562514.2875 37/64"0.578114.6844 19/32"0.593815.0813
1/2140.840 11/16"0.687517.4625 45/64"0.703117.8594 23/32"0.718818.2563
3/4141.050 57/64"0.890622.6219 29/32"0.906323.0188 15/16"0.937523.8125
111-1/21.315 1-1/8"1.125028.5750 1-9/32"1.281332.5438 1-5/32"1.156329.3688
1-1/411-1/21.660 1-15/32"1.468837.3063 1-31/64"1.484437.7031 1-1/2"1.500038.1000
1-1/211-1/21.900 1-23/32"1.718843.6563 1-23/32"1.718843.6563 1-3/4"1.750044.4500
211-1/22.375 2-5/32"2.156354.7688 2-3/16"2.187555.5625 2-3/16"2.187555.5625
2-1/282.875 2-25/32"2.781370.6438 2-5/8"2.625066.6750 2-5/8"2.625066.6750
383.500 3-9/32"3.281383.3438 3-1/4"3.250082.5500 3-1/4"3.250082.5500
3-1/284.000 3-3/4"3.750095.2500 3-3/4"3.750095.2500 3-3/4"3.750095.2500
484.500 4-1/4"4.2500107.9500 4-1/4"4.2500107.9500 4-1/4"4.2500107.9500
585.563 5-1/4"5.2500133.3500 5-9/32"5.2813134.1438 5-5/16"5.3125134.9375
686.625 6-1/4"6.2500158.7500 6-11/32"6.3438161.1313 6-3/8"6.3750161.9250
888.625            
10810.750            
12812.750            
14 (OD)814.000            
16 (OD)816.000            
Size
(in)		Threads/
Inch		Nom. OD
(in)		 Drill Size(in)(mm) Drill Size(in)(mm) Drill Size(in)(mm)
Equivalents Equivalents Equivalents
Taper NPT w/ Reamer * Taper NPT w/o Reamer Straight NPS
Pipe Tapping Drills

* Ream the hole before tapping with a reamer having a taper of 3/4 inch per foot.


Pipe Scheduling

Pipe Schedule 10 ** Schedule 40 ** Schedule 80 ** Schedule 160 **
Size
(in)		Nom. OD
(in)		 ID
(in)		Wall Thick.
(in)		 ID
(in)		Wall Thick.
(in)		 ID
(in)		Wall Thick.
(in)		 ID
(in)		Wall Thick.
(in)
1/80.405 0.3070.049 0.2690.068 0.2150.095   
1/40.540 0.4100.065 0.3640.088 0.3020.119   
3/80.675 0.5450.083 0.4930.091 0.4230.126   
1/20.840 0.6740.083 0.6220.109 0.5460.147 0.4660.187
3/41.050 0.8840.109 0.8240.113 0.7420.154 0.6140.218
11.315 1.0970.109 1.0490.133 0.9570.179 0.8150.250
1-1/41.660 1.4420.109 1.3800.140 1.2780.191 1.1600.250
1-1/21.900 1.6820.109 1.6100.145 1.5000.200 1.3380.281
22.375 2.1570.109 2.0670.154 1.9390.218 1.6890.343
2-1/22.875 2.6350.120 2.4690.203 2.3230.276 2.1250.375
33.500 3.2600.120 3.0680.216 2.9000.300 2.6260.437
44.500 4.2600.120 4.0260.237 3.8260.337 3.4380.531
55.563 5.2950.134 5.0470.258 4.8130.375 4.3130.625
66.625 6.3570.134 6.0650.280 5.7610.432 5.1890.718
88.625 8.3290.148 7.9810.322 7.6250.500 6.8130.906

** Because of differing manufacturing methods and tolerances, pipe ID and wall thickness may vary slightly from the values given.


Notes

Pipe Size is the accepted industry designation and does not refer to either the inside or the outside diameter (ID or OD) of a pipe or a fitting.

American National Standard Pipe Threads
NPT:  National Pipe Taper Thread
A sealant compound or Teflon tape must be used for a leak-free seal.
FPT:  female (internal) National Pipe Taper threads
MPT:  male (external) National Pipe Taper threads
NPTF:  Dryseal American National Standard Taper Pipe Thread
No sealant is needed for a seal.
NPS:  American Standard Straight Pipe Thread
Used for mechanical joining -- holding a fitting in place. An O-ring or a metal seal is required.
NPSF:  Dryseal American National Standard Straight Pipe Thread
 
British Standard Pipe Thread
BSPT:  British Standard Pipe Taper threads
BSPP:  British Standard Pipe Parallel (straight) threads

Other Resources

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DISCLAIMER

Page author: Dawn Rorvik (rorvikd@evergreen.edu)
Last modified: 05/20/2003