Identifying Genuine Rebar from Counterfeit: A Guide to Roll Marks and Factory Codes

A batch of substandard rebar that enters the warehouse without inspection is not merely a purchasing mistake. If that same batch reaches a contractor and is rejected during a site inspection, you are the one who must explain why you sold this material, not the factory that produced it. The good news is that identifying genuine rebar from counterfeit has several specific, learnable signs that can be checked even without access to a laboratory.

Before turning to the signs, let us clarify one point: counterfeiting in the rebar market usually does not take the form of producing rebar that has no real existence. More commonly, rebar is produced with a weight below the standard or with irregular ribs and sold as a product from a reputable factory, or claimed to have a grade higher than its actual grade. It is this subtler form of counterfeiting that requires informed judgment to detect.

Roll Mark; Where the Factory Leaves Its Signature

According to Iranian National Standard No. ۳۱۳۲, an abbreviated mark is engraved between the ribs on every deformed rebar. This mark consists of two parts: the manufacturer’s factory code, such as KSC for Khorasan Steel in Nishapur or ESCO for Esfahan Steel, and the production process code, which indicates the product’s rib type and grade. For example, if «KSC H» is engraved on the body of a rebar, it means that the product is from Khorasan Steel and its ribs are of the chevron type, Grade ۴۲۰.

The mark between the ribs usually has two parts: the factory code and the production process code. Learning these two is the fastest way to conduct a visual inspection.

Production Process Codes You Should Know

The second part of the abbreviated mark codes the rib type and grade with one or two letters. These codes are fixed and defined according to the standard; if you see a letter on the rebar that does not match any of these patterns, you should start asking questions right there:

Why Weight Is the Second Thing You Should Check

Rebar is bought and sold by weight, not by the number of bars. Standard ۳۱۳۲ defines an allowable deviation range for each rebar size relative to the theoretical weight in the اشتال table; that is, the actual weight is never exactly equal to the table value because the actual rolling diameter at each factory fluctuates slightly. The point is that if the delivered shipment weighs noticeably less than the اشتال table for that same factory, this is a more serious warning sign than any other visible indication, because it directly affects the actual strength of the structure. Weight reduction usually means that the actual rebar diameter is smaller than the claimed nominal diameter, and a smaller diameter means a smaller cross-sectional area for carrying loads.

Visual Inspection, Step by Step

Genuine rebar usually has a smooth, uniform surface. Cracks, flaking or excessive rust on the surface indicate inferior raw materials or an incomplete production process, not merely a cosmetic problem. The ribs should also have regular spacing and uniform depth; shallow or irregular ribs reduce the rebar’s bond with concrete and are exactly what prevents the rebar and concrete from behaving as one integrated unit. The identification plate on each bundle should also show the product specifications, bundle weight and production date; without this plate, the authenticity of a particular bundle cannot be traced, even if the rebar itself appears sound.

For Large Transactions, Go One Step Further

For large shipments or customers who conduct strict inspections themselves, the fastest approach is to request the tensile and bend test certificate for the same production batch from the factory or seller. This certificate shows whether the product’s actual yield stress and tensile stress match what is claimed on the roll mark. If the seller delays providing this certificate or makes excuses, that is itself a warning sign, even before you inspect the shipment.

• Read the roll mark: the factory code and production process code must match the seller’s claim.
• Compare the weight with the اشتال table for the same factory, not with an approximate figure from the internet.
• Check the surface and ribs for uniformity and depth.
• For a large shipment, request the tensile and bend test certificate before settlement.

None of these signs is conclusive on its own. It is the combination of the roll mark, weight, appearance and documentation that provides a reliable picture of the shipment’s authenticity, and this combination can save you from an expensive transaction and a rejected shipment.