Concrete and Masonry Practice Test

When selecting a steel angle lintel, the size is chosen to balance strength, span, and ease of installation. The cross-section shape (an angle) carries the load by bending, so the leg length and the thickness determine how much load it can safely span and how stiff it will be. For many standard openings in masonry walls, a stock size with equal legs of 3 1/2 inches and a thickness of 1/4 inch provides enough bending resistance while staying relatively light and economical. This size is widely available and fits typical door or window openings without being overly heavy or costly.

Larger options, like a 4 by 4 by 1/2 inch angle, are chosen when openings are bigger or loads are heavier, but they add weight and cost. Smaller or thinner options, such as 2 by 2 by 1/2 inches or 3 by 3 by 3/8 inches, may not provide adequate strength for common openings and loads, or are less common for standard installations. Therefore, the 3 1/2 by 3 1/2 by 1/4 inch size is the most typical, versatile choice for standard steel angle lintels.