Angle Iron

Angle irons, also known as angle bars, L bars, or L beams, are metal bars that are folded lengthwise at a 90-degree angle.
They offer structural support and framework to homes and buildings, as well as for stabilizing beams, furniture and shelving. These are found in different sizes, lengths, materials and colors.
 The type of angle iron that you choose will depend on the type of project that you are working on, the amount of weight that it will be supporting and where it will be located.

 

Regular Angle Irons

Regular angle irons are usually made of iron or steel, which provides strong support. They can also be made of brass, although these are more expensive and are used for aesthetic reasons.
Aluminum angle bars are used when someone wants a lighter metal for the support or if they will be placed in an area where rust is an issue.
The sizes vary, with the general rule that the longer the angle iron, the more weight it can hold and support. The number of holes that these have for attachment may vary.

Angle Brackets

Angle brackets are a type of angle bar that is folded along the width of the metal instead of the usually lengthwise fold.
These brackets are used for shelving supports and have holes punched in them so that they can be bolted to the wall.

Slotted and Punched Angle Irons

Slotted and punched angle irons have oval holes punched in regular intervals along the length. Frequently the holes are 1 inch apart and allow for even weight distribution. These types of angle irons are usually used for commercial and garage shelving and are assembled through the holes with nuts and bolts.

Angle Iron Hanger Weight

Angle irons are L-shaped flat galvanized steel struts used for a wide range of construction and household functions. Large angle irons often help stabilize steel beams while smaller angle irons are used to construct household items such as bed frames, benches and shelving.

Most angle irons have pre-punched holes spaced at regular intervals to offer screw installation to support various weights or tensions at various lengths. For construction purposes and as supports in solid materials such as wood or metal, the weight bearing capacity of the angle iron is integral to overall structural integrity.

For shelving screwed into drywall, the weight bearing capacity of the angle iron must also include calculations for the weight-bearing capacity of the anchor bolts.

Sizing and Lengths

Angle irons are measured by their vertical length, horizontal length and thickness, usually in that order. So if you're looking for a 3-inch by 3-inch by ½-inch angle iron, you would specify the lengths followed by the thickness. A single angle iron that size screwed into solid wood or other solid material can support 3.9 lbs. of dead weight.
If the angle iron is used for shelving, you would use at least two to hold 7.8 lbs. Three angle irons could support 11.7 lbs.
By comparison, a 6-inch by 6-inch angle iron that is ½ inch thick can support 19.6 lbs and, since you would need at least two angle irons of that size to stabilize a shelf, the shelf could hold 32.9 lbs. A third angle iron would enable the shelf to hold 42.5 lbs.

Angle Irons in Wallboard

Using angle irons in drywall requires an extra calculation to ensure that the load weight capacities of the angle irons don’t overstress the anchor bolts or toggle bolts you need to hang shelving.
Using the 6-by-6 example, a toggle bolt of 1/8-inch diameter would hold up to 30 lbs. before it would pull away from the wallboard. So, you would need a toggle bolt of twice that diameter, or ¼ inch, to handle 50 lbs. of tension weight.

Industrial and Construction Uses

Angle irons are versatile in industrial and general construction uses. There is a direct correlation between the size of an angle iron and its weight capacity.
In commercial use, they are commonly used for building reinforcement, athletic flooring systems, joists, studs and control and expansion joints.
Their usefulness extends to railroad track and supports, and a host of uses in the aerospace, automotive, HVAC, hardware and storage industries.
When using large angle irons, you can calculate weight capacities using software.