Aluminum discs for road signs can be stamped and formed on stamping equipment and production lines. Due to their low density and easy forming characteristics, the aluminum road signs are commonly seen on the market. Circular traffic signs are 60cm, 80cm, 100cm in diameter; cracks, obvious bubbles, scratches, and damage are not allowed on the surface. The aluminum circle for road sign should be flat, without obvious wrinkles, dents or deformation on the surface, and the unevenness of the layout should not be greater than 7mm/m; the general dimension deviation is ±5mm, if the dimension is greater than 1.2m, the deviation is ±0.5 of the external dimension %.
Traffic sign boards can be made of aluminum discs, extruded aluminum alloy profiles, thin steel plates, synthetic resin plates, etc. The common used grade of aluminum circle for road sign are 3003, 3004 or 3104 aluminum alloy plate. Because 3000 series aluminum has better corrosion resistance performance. The minimum measured thickness of the aluminum circle disc used for the sign bottom plate shall not be less than 1.5mm; the large sign plate should adopt 2–3mm plate. The chemical composition, cold-rolled plate brand, specifications, mechanical properties, dimensions and allowable deviations of aluminum circle discs shall meet the requirements.
Because of aluminum discs for road signs has light weight and corrosion resistance, it is widely used. The surface material of road traffic signs is made of high-quality aluminum alloy plate, and the pictures and texts generally use engineering grade or high-strength reflective film, which has a good reflective effect at night.