Pipe taps are available in various thread forms, including:

ANPT-USA Aeronautical National Pipe Taper

ANPT thread is used in the more high-end technical work fields which Used for a process such as transportation or chemical ,

ANPT that is very similar to NPT. ANPT-Aeronautical National Pipe Taper

NPT requires to make a true sealing, while ANPT threads crush in to make a dry seal no need extra sealing.

BSP-UK British Standard Pipe

BSP is the standard adopted in plumb and pipe and fitting in most countries

While another widely applied in USA is NPT.

BSPP-UKBritish Standard Pipe (Parallel) Thread

Thread accordance with ISO 228-1

Pitch & diameter taken in inches

Parallel threads need o-ring, crush washer, seal between joints for high pressure tight connection

Tap angle is 55°

Thread Size = Male Thread OD - Threads per Inch

BSPT-UK British Standard Taper Pipe Thread

Thread accordance with ISO 7

Pitch & diameter measured in inches

Tapered thread  seals by metal to metal fit, usually requires seal for pressure tight connection

Thread tap angle is 55°

NPS-USA For tap marking only (See NPSC, NPSM)

Dimensions of NPS - American National Standard Straight Pipe Thread -

not self-sealing threads are indicated below:

USANPT and NPS both have the same thread angle 60° , shape, and TPI. However,

NPT taps are tapered and NPS taps are straight. Both taps have 60° angle and flat peaks

NPT-USA American National Standard Taper Pipe Thread (See ANPT, NPTR)

NPT is a U.S. standard for taps used to join pipeline and fittings which is defined by ANSI B1.20.1 Pipe Threads standard, General Purpose, Inch

NPT threads have a 60° thread angle

NPTF-USA National Pipe Thread Tapered Fine (also called Dryseal American National Standard Taper Pipe Thread)

NPTFis a U.S.A standard for TAPS used for joining pipes and fittings is defined by ANSI B1.20.3. that is designed to provide a much closely seal without the use of PTFE tape ("Teflon") NPTF taps have the same basic work shape but with crest and root heights with an interference fit,  which eliminate the spiral leakage path.

NPTR-American National Standard Taper Pipe Thread for Railing Joints (Tap marked NPT

UK BSP Threads vs USA NPT Threads

Depending on contries where you live on , these threads can be very different,Both NPT and BSP threads are pipe thread standards for screw taps that experts use for pipes, pipe fittings, and pressure seals industries.

British Standard Pipe Thread (BSPT) is used mostly in Europe countgry and the UK. National Pipe Thread (NPT) is the most common applied thread for pipes and nozzles in USA