Correct measurement method for transverse dimensions of steel H beam
Previously, customers often complained that the H-beam steel they purchased was oversized. When asked to send a photo of their actual measurement, it turned out that their methods varied greatly.
Firstly, the measuring tools were not professional. To measure the height of the web and the width of the flange, you must use a caliper, and for the thickness, you need a micrometer or a dedicated thickness gauge.
Using a tape measure or leather tape to measure height and width is not suitable and is even less suitable for measuring thickness. The thickness tolerance for small steel H beams is only 0.5mm.
The correct method to measure steel H beam dimensions:
H beam web height should only be measured along the web centerline as shown in the diagram below:
Measuring the height of the web is where errors most often occur. Because steel sections are often stacked for storage and the ends have burrs, it is inconvenient to measure, and some, for convenience, measure the ends of the flanges on the outside of the stack, but this may lead to data deviations. The following image shows an incorrect method:
The two flanges of an H beam are not always parallel; sometimes they may be slightly tilted. Although they may appear parallel to the naked eye, a slight slope on a 200mm wide flange can result in a height deviation of several millimeters at the edges.
Therefore, it is essential to follow the correct measurement method and ensure that any burrs on the ends are removed or flattened for accurate measurement.
When measuring flange width, the caliper should be placed at an angle to ensure contact is not just at one point, but over an area, as shown in the diagram below:
Errors in measuring web and flange thickness are less common. The standard indicates that the flange thickness is measured in position B/4, and the web thickness is measured in position H/2, as shown in positions t1 and t2 in the diagram below:
However, this does not mean that other areas can exceed 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 shall not exceed the upper and lower limits of the standard thickness.
Different regulations apply to flange ends, as specified in GB/T 11263, which also includes many other measurement methods and dimension requirements. Here, we present just some of the most concerning measurement methods.
Correct measurement method for cross-sectional dimensions of steel I-beams
The measurement of web height, flange width and web thickness for I beam steel is similar to that of H beam steel. What often confuses us is the measurement of flange thickness. The standard method is to use a micrometer, measuring at position (bd)/4 of the end of the flange, at the position marked t, as shown in the diagram below.
From the front view, the enlarged micrometric measurement point is shown in the following diagram, with the thickness indicated by the yellow line representing the thickness of the steel I-beam.
From the side view, the measuring point of the enlarged micrometer should be a small distance from the end of the steel I-beam to avoid pressing burrs and affecting the measurement result.
After seeing the diagrams above, measuring the steel channel dimensions should also be simple. Only the formula for calculating the flange thickness is different, which can be understood by referring to the standard.
