Metric Pipe Thread Size Guide

Save

Most of the world uses the metric system to measure pipe sizes. However, America, Liberia and Burma still use the Standard English system. Converting pipe size from standard to metric can be confusing but knowing them can be useful in day-to-day pipe work.

Under an Inch

  • An eighth of an inch is equivalent to six millimeters, while three sixteenths is equal to seven millimeters. One quarter of an inch is eight millimeters and three eights is 10. Half an inch is 15 millimeters, five eighths is 18 and three quarters is 20 millimeters.

One Inch

  • One inch is the same as 25 millimeters. Another quarter inch equals 32 millimeters. An inch and a half is the same as 40 millimeters. Pipe measurements don’t come in any more sizes that are less than two inches.

Two Inch

  • Adding another inch to your first inch will give you 50 millimeters. Two and a half millimeters is equivalent to 65 millimeters. There are no more metric pipe measurements that are below three inches.

Three Inch

  • The synchronization between millimeters and inches is not perfect. For example, three inches is not 75 millimeters, as you might expect, but 80 millimeters; three and a half inches are 90 millimeters.

Four Inch

  • Four inches equals 100 millimeters. This is another moment of non-perfect interaction between the systems. The next measurement less than five inches is four and a half inches, which equals 115 millimeters.

Five and Over

  • The last two pipe measurements are more uniform to early conversion rates. Five inches is 125 millimeters while six inches is 150.

References

  • Photo Credit Jupiterimages/Photos.com/Getty Images
Promoted By Zergnet

Comments

You May Also Like

  • Rc 1/8 Metric Pipe Tap Information

    British standard pipe taper (BSPT) internal thread is called Rc by the International Organization for Standardization (ISO). Rc refers to an internal,...

  • Metric HeliCoil Drill Sizes

    Metric HeliCoil inserts require the use of metric drills and taps to create the proper threading for the HeliCoil insert, regardless of...

  • How to Determine NPT Pipe Sizes by Measurements

    The National Pipe Tapered Thread (NPT) was created in 1864 to set a standard of measurement. An NPT pipe has a tapered...

  • How to Measure Metric Screw Threads

    Metric screws are measured differently than American screws. In addition to using metric units, instead of measuring threads per inch, the metric...

  • How to Convert Metric Threads to English Threads

    Metric and English screw threads are two different systems of standardization for screws and bolts. Both systems characterize screws by two main...

  • How to Size a Metric Screw

    By using a few simple measuring tools and referencing the metric screw dimension charts, you can size a metric screw according to...

  • How Are Pipe Fittings Sized?

    The sizes of pipe fittings can be very confusing because the sizes do not refer to any of the physical dimensions of...

  • How to Identify Pipe Thread Size

    Pipes are used for many different tasks within homes and buildings, even if they are not something that you often think about....

  • SAE Thread Specifications

    The Society of Automotive Engineers or SAE has standards for the number of threads per inch that should be on machine screws...

Related Searches

Check It Out

22 DIY Ways to Update Your Home on a Small Budget

M
Is DIY in your DNA? Become part of our maker community.
Submit Your Work!