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What is a 1/2 BSP thread?

What is a 1/2 BSP thread?

For example a 1/2″ BSP thread (see above) actually measures more like 3/4″ with a ruler. The size was originally based on the inside diameter, measured in inches, of a steel pipe for which the thread was intended.

How do you measure 1/2 inch BSP?

Use a tape rule (or vernier gauge) to measure across the outside of the male thread. Note that a thread that measures 1/2″ is not a 1/2″ BSP thread. Using the table below we can see that a thread measuring 1/2″ is actually a 1/4″ BSP thread. Similarly, a thread that measures 1″ is actually a 3/4″ BSP thread.

How do you read BSP thread size?

To find the thread size:

  1. 1) Measure the O.D (outer diameter) of the BSP thread.
  2. 2) Take the O.D measurement (in inches) and subtract 1/4 inch (. 25”).
  3. 1) Multiply 3.5 by 4 to get 14. This is the number of threads per inch.
  4. 2) Combine the thread size with the number of threads per inch and refer to.

What does BSP mean in threads?

British Standard Pipe
BSP thread form stands for British Standard Pipe and is common in Australia and the commonwealth countries. It is based on trade size rather than actual diameter which can lead to some confusion when measuring ports. There are two types of BSP threads; – BSPP – Female & male thread are both (also known as G)

What size thread is 1/2 pipe?

Basic Dimensions, American National Standard Taper Pipe Threads, NPT, (ANSI B2. 1-1968)

Nominal Pipe Size Outside Diameter of Pipe Threads per Inch
1/4 0.540 18
3/8 0.675 18
1/2 0.840 14
3/4 1.050 14

Is 1/2 inch BSP the same as 15mm?

Whilst most 15mm compression fittings are 1/2″ bsp, (some earlier ones had finer threads) the same cannot be said for 10mm and 8mm.

How do you measure thread size?

Determine the diameter and the length of the threaded area. Measure from the bottom of the head to the end of the threaded area in millimeters. For instance, it might be 8 millimeters. Then, measure the diameter (width) of the threaded area in millimeters. This might be 4 millimeters across.

What is a 1/2 NPT thread?

Basic Dimensions, American National Standard Taper Pipe Threads, NPT, (ANSI B2. 1-1968)

Nominal Pipe Size Outside Diameter of Pipe Threads per Inch
1/8 0.405 27
1/4 0.540 18
3/8 0.675 18
1/2 0.840 14

What is pipe thread size?

Pipe Thread Sizes Pipe thread sizes are based on an inside diameter (ID) or flow size. For example, “1/2–14 NPT” identifies a pipe thread with a nominal inside diameter of 1/2 inch and 14 threads to the inch, made according to the NPT standard. If “LH” is added, the pipe has a left hand thread.

What is a BSP fitting?

British Standard Pipe (BSP) is a set of technical standards for screw threads that has been adopted internationally for interconnecting and sealing pipes and fittings by mating an external (male) thread with an internal (female) thread.

What is the TPI of 1/2 20 thread?

Unified Thread Series 20 TPI ANSI/ASME B1. 1

Nominal Diameter Major Diameter Inch TPI
1 1/2″ – 20-UN 1.5000 20
1 9/16″ – 20-UN 1.5625 20
1 5/8″ – 20-UN 1.6250 20
1 11/16″ – 20-UN 1.6875 20

What does thread size mean?

Inch thread sizes are specified by diameter and threads per inch. Diameter is also known as screw size. For those with a diameter smaller than 1/4″, screw size is indicated by a number (e.g., #10 or No. 10). For example, a 10-24 screw has 0.190″ thread diameter and has 23 threads per inch.

What size is BSP?

Just to confuse you, we generally refer to a fitting by size, a 1” BSP nipple is also known as a 25mm BSP nipple but this actually refers to the inside diameter. The outside diameter for a 1” BSP fitting is not 1” or 25mm it is in fact 33.249mm at the widest point.

What is BSP size?

Minor diameter is the measurement of the inside of a female threaded connection, from thread to thread. BSP Size. Also Known As. Actual Diameter (Imperial) Actual Diameter (Metric)

How is TPI calculated?

Measuring Imperial Thread Pitch As the name suggests, TPI is measured by counting the number of thread peaks along a 1 inch length. The TPI measurement is then often affixed to the diameter of the thread to form a common imperial thread size, e.g. ‘1/4-20’, which would denote a ¼ inch diameter, and 20 threads per inch.

What is half inch fine thread?

National Fine Thread Sizes (UNF/UNRF)

National Fine Thread Sizes (UNF/UNRF) Measured in Inches
Nominal Size Major Diameter Minor Diameter
7/16 0.438 0.383
1/2 0.500 0.446
9/16 0.563 0.502

How are inch threads measured?


  1. Measure an inch-long portion of the threaded area. Grab a ruler and lay it along the bolt or screw.
  2. Count the number of threads in 1 inch.
  3. Measure the diameter and the length of the threaded area.
  4. Plug the information into a standard measurement.

What is thread size in mm?

Tap size Basic major dia (mm) mm per thread
M12 x 1.25 12mm 1.25
M14 x 2 14mm 2
M14 x 1.5 14mm 1.5
M16 x 2 16mm 2

How is BSP measured?

The easiest way is to count the thread crests over a shorter length, say 1/4″, and simply multiply it by 4. For example, if you count 3.5 thread crests over 1/4″: 3.5 x 4 = 14 threads per inch. Take this measurement and cross-reference it to your thread size in the chart below.

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