Rebar is a widely used material in the construction industry. Most of the concrete used in the construction of buildings and bridges is reinforced with rebar. Rebar increases the applications of concrete, and is available in different grades, each ideal for certain construction applications. Grade 60 rebar is one of the most widely employed grades of rebar for concrete. Grade 60 rebar's metric equivalent is referred to as grade 420 rebar.
Rebar offers nearly countless practical applications. Rebar is cast into concrete or masonry to provide an increased level of strength and reinforcement for the material. Concrete and materials such as brick and stone offer relatively low tensile strengths. Tensile strength indicates the ability of a material to deform instead of break or crack under pressure. Adding rebar such as grade 60 rebar to concrete greatly increases the overall tensile strength of the concrete.
Different grades of rebar offer different tensile strengths and elongation. Elongation refers to the measurable amount of deformation a material undergoes under pressure before the material ultimately fractures or breaks apart. Grade designations typically indicate tensile strength. For example, grade 60 rebar offers 60,000-psi minimum tensile strength. An 8-inch bar of grade 60 rebar offers between 7 and 9 percent elongation before snapping.
Most grades of rebar, including grade 60 rebar feature deformations. Deformations are patterns rolled across or around rebar to help concrete grip to the rebar. The spacing between rolls is uniform across the length of the rebar run. Grade 60 rebar features one bar that wraps along the length of the rebar and one deformation bar that runs in a straight line down the length of the rebar.
Rebar is manufactured with markings that identify the attributes of the rebar. Grade 60 rebar features a "60" or "4" stamped on the rebar. Markings on rebar also indicate what type of material the rebar is made out of. The diameter of rebar is also stamped on the rebar. The manufacturers of rebar offer markings that indicate exactly what company produced the rebar. The bottom number stamped on rebar indicates the grade of rebar -- 60 or 4 for grade 60 rebar. The marking right above the bottom number indicates the material used in the construction of the rebar. For example, an "S' indicates that the rebar is made of carbon steel. The number above the material number indicates the diameter of the rebar. An "11" indicates that the rebar is 1.410 inches in diameter (diameter does not include the size of the deformations). The top number lets the consumer know what manufacturer produced the rebar.