Free technical reference guides for engineers, fabricators, and procurement specialists. Our resource library covers thread identification charts (BSPP, BSPT, NPT, and Metric), pressure and temperature unit conversions, length conversions, and thread sealing principles for pneumatic, hydraulic, and instrumentation applications.
Whether you’re matching fittings across measurement systems or converting specifications between psi, bar, kPa, and MPa, these charts give you the answers you need without leaving your workbench.
British Standard Parallel pipe threads with face seal applications
British Standard Taper pipe threads for sealing applications
National Pipe Taper — the US standard for tapered threads
Metric fitting threads M5–M18 with pitch and dimensions
Convert between bar, psi, kPa, and MPa instantly
Celsius to Fahrenheit conversion table and formulas
Millimetres to inches with fraction equivalents
When to use thread tape, sealant, or face seals
BSPP (British Standard Pipe Parallel) and BSPT (British Standard Pipe Taper) use similar thread sizes, but they seal differently. BSPP threads are parallel and require a bonded washer or O-ring to create a seal. BSPT threads are tapered and seal through thread interference, typically with thread tape or liquid thread sealant. BSPP is commonly used in pneumatic and instrumentation systems, while BSPT is often used where a tapered self-sealing connection is required.
NPT (National Pipe Taper) and BSPT (British Standard Pipe Taper) are both tapered thread systems, but they are not interchangeable. NPT threads use a 60° thread angle, while BSPT threads use a 55° thread angle. Thread pitch and dimensions also differ. Attempting to connect NPT and BSPT fittings together can damage threads and result in leaks.
Yes. A BSPT male thread can often be installed into a BSPP female port using thread tape or thread sealant. The tapered male thread wedges into the parallel female thread to create a seal. This method is commonly used in pneumatic and instrumentation applications, although dedicated sealing methods should always be used where specified by the equipment manufacturer.
No. Metric and BSPP threads are parallel thread systems and do not normally seal on the thread itself. Sealing is achieved using an O-ring, bonded washer or sealing face. Applying thread tape or sealant is generally unnecessary and may interfere with correct sealing.
To convert psi to bar, divide the psi value by 14.5.
Example:
100 psi ÷ 14.5 = 6.9 bar
To convert bar to psi, multiply by 14.5.
Common reference values:
To convert Celsius (°C) to Fahrenheit (°F):
°C × 1.8 + 32 = °F
Example:
100°C = 212°F
To convert Fahrenheit to Celsius:
(°F − 32) × 5 ÷ 9 = °C
The temperature conversion chart on this page provides quick reference values for common industrial temperature ranges.
DN (Diameter Nominal) is a standardised reference size used to classify pipes, industrial hoses and fittings. It helps ensure compatibility between components across different manufacturers and systems.
DN is typically expressed in millimetres and represents an approximate internal diameter, rather than an exact measured dimension.
DN sizing is often used alongside D (Outside Diameter), which refers to the actual external measurement of a pipe or tube in millimetres.
For example:
DN sizing is widely used in industrial process systems, pneumatics, hydraulics, plumbing and instrumentation applications to simplify component selection and ensure system compatibility.
Use the chart that matches the thread type you are working with:
If you are unsure which thread type you have, compare the thread dimensions, pitch and sealing method shown in the charts before selecting replacement fittings or adapters.
