Specifying the correct grade, size and coating for MS and GI angles and channels affects both project cost and structural performance. This guide breaks down the technical side of these products — the standards they are tested against, the size ranges commonly stocked, and how to decide between mild steel and galvanized options for a given application.
Grades and Standards
MS angles and channels are typically supplied to ASTM A36, BS 4360 / EN 10025 (S275JR, S355JR) or equivalent structural steel grades, giving a minimum yield strength suited to general fabrication and framing work. GI angles and channels start from the same base steel but are hot-dip galvanized to BS EN ISO 1461, with a zinc coating measured in microns and rated for the corrosion environment — an important spec to confirm for coastal and industrial sites in the UAE.Common Sizes and Thickness Ranges
Equal and unequal angles are generally stocked from 25x25mm up to 200x200mm, in thicknesses from 3mm to 20mm, while channels run from 75x40mm up to 400x100mm depending on the application. Confirming leg length, thickness and channel depth against the structural drawing before ordering avoids costly on-site rework.MS vs GI: Choosing the Right Option
MS angles and channels are the more economical choice for indoor framing, machine bases and applications where the steel will be painted or is not exposed to moisture. GI angles and channels cost more upfront but remove the need for repeat painting, which typically works out cheaper over the life of an outdoor structure, rooftop support or boundary fencing exposed to the UAE climate.Fabrication and Site Handling
Both MS and GI sections can be cut, drilled and welded on site, though welding through a galvanized coating burns off the zinc locally and should be followed by a cold-galvanizing touch-up spray to restore corrosion protection at the joint. Standard mill lengths run 6 metres, and Mufaddal Steel can also cut to size for projects that need shorter, ready-to-install pieces.Mufaddal Steel Trading LLC stocks MS and GI angles and channels across these standard grades and sizes, with cutting and delivery support for projects across the UAE. Share your drawing or size list with our team for a same-day stock check and quotation.