How to Size Round Metal Pipes

Metal pipe is measured by its length and diameter.

Metal pipe comes in all different sizes and length. Some tasks require you to know the rough dimensions of a round metal pipe but some projects require that you know the exact dimensions. When sizing metal pipe you need to know the overall length of the pipe, the outside diameter (OD) and the inside diameter (ID.) Knowing the exact size of the pipe lets you know if the pipe will suit your needs.

Things You'll Need

• Tape measure
• Dial calipers

Instructions

1. Take a tape measure and place the one-inch mark on the end of the pipe. Extend the tape measure to the other end of the pipe to obtain the length measurement. Subtract one inch from the reading to compensate for starting at the one-inch mark. Starting at the one-inch mark on the tape measure eliminates inaccuracies due to the metal clamp attached to the end of tape measures.

2. Stretch the tape measure across the face of the pipe to determine the overall rough measurement of the pipe. If the pipe is less than 6 inches across, obtain a 0- to 6-inch dial caliper. If the pipe is between 6 inches and 12 inches across, obtain a 6- to 12-inch dial caliper.

3. Place the lower jaw of the dial caliper around the outside of the pipe and read the measurement on the caliper. This gives you the outside diameter of the pipe.

4. Place the internal jaws of the dial caliper against the inside walls of the pipe and read the measurement on the caliper. This gives you the inside diameter of the pipe.

References

• Tresna Instrument: How to use and read a dial caliper correctly