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How to measure the radius of curved steel sections

This formula allows you to accurately determine the radius of the curved steel section even when dealing with less than 180 degrees of arc. You should also check out our Bending Process page.

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Measuring the radius of a curved steel section accurately is crucial for various applications in construction, manufacturing, and engineering. Whether it’s a curved steel angle, beam, bar, or channel, understanding how to measure the radius precisely is essential. Here’s a step-by-step guide on how to measure the radius of a long steel section when you have less than 180 degrees of arc.

Tools Needed:

  • One string
  • Two magnets
  • One measuring tape

Step One: Create a Chord Begin by creating a chord, which is a straight line connecting two points on the curve. Secure one end of the string to the curved steel section using a magnet. Then, use another magnet to secure the string taut at the other end of the steel section. Measure the distance between the two endpoints of the string using a measuring tape. This measurement represents the chord length. Remember, the longer the chord you create, the more accurate your radius calculations will be.

Step Two: Create a Midpoint Next, find the midpoint of the chord. Simply divide the chord measurement obtained in step one by two. This calculation will give you the midpoint of the chord.

Step Three: Create a Rise Measure the distance 90 degrees off the midpoint of the chord to the curved steel section. This measurement is referred to as the “mid-ordinate rise” or simply the “rise.” Ensure accuracy in creating a right angle with your measuring tape and string, as it will impact the precision of your radius calculations.

To calculate the radius of the curved surface, use the following mathematical formula along with the chord length found in step one and the rise measured in step three:

Radius = 1/2 (rise2 + 1/4 chord2

This formula allows you to accurately determine the radius of the curved steel section even when dealing with less than 180 degrees of arc. Alternatively, you can use a Digital Radius Gauge/Arc Meter for precise measurements, especially in industrial settings where accuracy is paramount. By following these steps and using the appropriate tools, you can ensure precise measurements for your steel fabrication and construction projects.

arc meter

Arc Meter

Digital Radius Gauge/Arc Meter is a precision measurement tool used to determine the radius of curved surfaces with high accuracy. It typically consists of a handheld device equipped with digital sensors and a digital display screen. The gauge is designed to be placed against the curved surface, and it measures the radius automatically, displaying the result on the digital screen. This type of gauge offers advantages over traditional manual radius measurement methods by providing faster, more accurate, and consistent results. It is commonly used in manufacturing for quality control, inspection, and dimensional verification purposes.

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