Measuring Cross-Section Dimensions of H-Beams and I-Beams: A How-To Guide | MachineMFG

Inquire About Our Sheet Metal Machines Now!

Measuring Cross-Section Dimensions of H-Beams and I-Beams: A How-To Guide

0
(0)

Correct Measurement Method for the Cross-Sectional Dimensions of H-Beam Steel

Previously, customers often complained that the H-beam steel they purchased was oversized. When asked to send a photo of their actual measurement, it was found that their methods varied greatly.

First of all, the measuring tools were not professional. To measure the height of the web and the width of the flange, a vernier caliper should be used, and for thickness, a micrometer or a dedicated thickness gauge is required.

Vernier Caliper
Vernier Caliper
Micrometer (Screw Micrometer)
Micrometer (Screw Micrometer)

Using a tape measure or a leather tape to measure the height and width is not appropriate, and it is even less suitable for measuring thickness. The thickness tolerance for small H-beam steel is only 0.5mm.

The correct method to measure the dimensions of H-beam steel:

The height of the H-beam’s web should only be measured along the central line of the web, as shown in the diagram below:

measure the dimensions of H-beam steel
Web Height Measurement

Measuring the height of the web is where errors most commonly occur. Since the steel sections are often stacked for storage and the ends have burrs, it’s inconvenient to measure, and some, for the sake of convenience, measure the ends of the flanges from the outside of the stack, but this can lead to data deviation. The following image shows an incorrect method:

incorrect method
Incorrect Measurement Method

The two flanges of an H-beam are not always parallel; sometimes, they can be slightly tilted. Although they may appear parallel to the naked eye, a slight tilt in a 200mm wide flange can result in a height deviation of several millimeters at the ends.

Therefore, it is essential to follow the correct measurement method and ensure that any burrs on the ends are either removed or flattened for accurate measurement.

When measuring the width of the flange, the vernier caliper should be placed at an angle to ensure that the contact is not just at a point but over an area, as shown in the diagram below:

Flange Width Measurement
Flange Width Measurement

Errors in measuring the thickness of the web and flanges are less common. The standard indicates that the thickness of the flange is measured at the B/4 position, and the thickness of the web is at the H/2 position, as shown at the t1 and t2 positions in the diagram below:

thickness of the flange is measured at the B/4 position

However, this does not mean that other areas can exceed the standard requirements. Except near the connection point (inner arc), where the R-corner may cause the thickness to exceed the upper limit of the standard, other areas must not exceed the upper and lower limits of the standard thickness.

Different regulations apply to the ends of the flanges, as specified in the GB/T 11263 standard, which also includes many other measurement methods and requirements for dimensions. Here, we only introduce a few of the most concerning measurement methods.

Correct Measurement Method for the Cross-Sectional Dimensions of I-Beam Steel

The measurement of the height of the web, width of the flange, and thickness of the web for I-beam steel is similar to that of H-beam steel. What often confuses us is the measurement of the thickness of the flange. The standard method is to use a micrometer, measuring at the (b-d)/4 position from the end of the flange, at the position marked t, as shown in the diagram below.

Measurement Method for the Cross-Sectional Dimensions of I-Beam Steel

From the front view, the enlarged micrometer measurement point is shown in the following diagram, with the thickness indicated by the yellow line representing the thickness of the I-beam steel.

micrometer measurement point

From the side view, the enlarged micrometer measurement point should be a little distance from the end of the I-beam steel to avoid pressing down on burrs and affecting the measurement result.

measurement point

After seeing the above diagrams, measuring the dimensions of channel steel should also be straightforward. Only the calculation formula for the thickness of the flange is different, which can be understood by referring to the standard.

How useful was this post?

Click on a star to rate it!

Average rating 0 / 5. Vote count: 0

No votes so far! Be the first to rate this post.

As you found this post useful...

Follow us on social media!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Just a Step Away!

Sheet Metal Machines Await!

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top