Detecting Undersizing and Fraud When Buying Steel Sheets

You buy a “۳ میلی‌متری” black sheet, the load arrives, and it looks exactly like a ۳ میلی‌متری sheet. But when you measure it with a micrometer, the actual thickness is ۲.۷ میلی‌متر. This ۰.۳ میلی‌متر cannot be seen with the naked eye, but because sheet prices are based on weight and weight is directly dependent on thickness, this small difference means that around ۱۰ percent of the money you paid was for steel you never actually received.

Why Sheet Fraud Differs from Rebar and I-Beams

In rebar, the main fraud involves reducing the diameter, while in I-beams it involves reducing the flange thickness. With sheets, the matter is simpler and, at the same time, more concealed: the sheet’s own thickness is what determines both the price and the easiest place to commit fraud. Since sheet thickness is measured in tenths of a millimeter, a small difference that cannot be detected by eye can shift a significant percentage of the weight and, consequently, the price.

With sheets, it is those few tenths of a millimeter in thickness that create the price difference—something visible only through measurement, not by looking.

Three Main Signs of a Suspicious Sheet

Weight Check: Your Simplest Weapon

The good thing about sheets is that their weight can be calculated exactly. If you have a sheet measuring ۲ by ۱ meters with a thickness of ۳ میلی‌متر, its theoretical weight is ۲ × ۱ × ۳ × ۷.۸۵, equal to ۴۷.۱ kilograms. If the actual weight on the weighbridge is noticeably lower than this figure, it is cause for concern. This check can also be performed on the entire load: calculate the total theoretical weight of all the sheets and compare it with the weighbridge weight.

A few minutes of measurement with a micrometer and a simple calculation, for a product priced by the kilogram, can prevent a loss that becomes a significant amount across an entire large load.