Table of Common and Uncommon Thread Types

From

http://www.dent-mfg.com/threadsizes.htm

NPSH: American Standard Straight Pipe for Hose Couplings (National Pipe Straight Hose)

NPTF American Standard Taper Pipe Fuel Dry Seal Thread (National Pipe Tapered)

NPT American Standard Taper Pipe Thread (National Pipe Tapered)

NPT: Nations Pipe Thread, This is your standard american pipe thread.

Size    Thread   Dia    Length
1/16    27  .312    .261
1/8     27  .405    .264 
1/4     18  .540    .402
3/8     18  .675    .408
1/2     14  .840    .534
3/4     14  1.050   .546
1   11-1/2  1.315   .683
1-1/4   11-1/2  1.660   .707

NPTF: Same as above but dry seal.