The Difference Between IPE, INP, and IPB I-Beams from a Buying and Selling Perspective

A customer says on the phone: “I want an 18 I-beam, one of the regular ones.” This seemingly simple sentence actually has three possible answers: INP, IPE, or IPB, each with a different flange shape and better suited to different applications. Selling the wrong option, even with the same nominal size, may cause the customer to realize after installation that the product was not suitable for their work.

The real difference between these three types is in the flange shape

What many first-time buyers do not know is that “18 I-beam” is not a specific size by itself; it is a number alongside a section type. INP is the oldest common standard in the Iranian market, and its flange is sloped with variable thickness. IPE is a newer, more European standard, with parallel flanges and uniform thickness that make calculation and installation easier. IPB, known as Hash, has wider flanges and is designed for heavier loads.

The flange shape is what distinguishes IPE from INP and IPB—not the color, not the brand.

An example conversation with a customer

The customer says: “I need it for a shed; whatever is cheaper.” The right answer is not to immediately suggest the cheapest option. The right answer is to ask: “Is this I-beam for the shed’s main column or for the secondary frame and roof?” If the loading is heavy, IPB is usually the better choice, even if the price per kilogram is higher; because in the end, the required strength can be achieved with a smaller size.

Why this difference affects your price and profit

Because of its wider flanges, IPB usually weighs more than IPE in the same size. This means the final price of each section also increases, even if the price per kilogram is the same. If you sell IPB instead of IPE to a customer who was only looking for a lower price without explaining this difference, they will think they have been cheated, even if the product is completely suitable.

When INP still has buyers

• Repair projects that must be compatible with the old I-beams in the same structure.
• Customers who rely on their old habits or on a previous contractor, without a clear technical reason.
• Some non-structural applications that do not require high dimensional accuracy.

Ultimately, which type of I-beam you should recommend must start with a simple question: Which part of the structure is this I-beam for? The answer to this question usually determines the choice between INP, IPE, and IPB—not the price on the board.