Details
Starrett Steel Combination Square with Square Head and Center Head - 12" Blade Length, Hardened Steel, Reversible Lock Bolt, Scriber, Spirit Level - 4R Graduation -11HC-12-4R

Designed for Precision - The ruler has a 4R graduation type with 8ths, 16ths, quick reading 32nds, and 64ths that greatly increase the accuracy of your measurements.
The Perfect Attachment - The Center Head is an available attachment that provides an easy means of accurately locating the center of cylindrical or square work.
Variety of Uses - The square head can be used for a variety of purposes such as scribing right angles and parallel lines, measuring, tri-squaring, mitering, depth gauging, height gauging, and levelling.
Quality Made - The blade is made of hardened steel, offering exceptional durability and resistance to wear, rough usage, high-impact pressure, and shock.
Versatile Layout Tool - Starrett squares are offered in a practical variety of styles to suit the needs of the individual, whether it be a toolmaker, mechanic, carpenter, or a "do-it-yourself" homeowner.
The combination square with center head is a basic combination set. The center head is a convenient and accurate way to find the center of round work. Starrett combination square consist of a machine-divided, hardened and tempered steel rule (or blade) on which is mounted an adjustable square head. A reversible lock bolt allows the blade to be turned over or end-for-end without removing the lock bolt or nut. This ensures true alignment of the blade and heads. Square head are made of cast iron and are not to be confused with the cheap imitation plastic or die cast heads on the market. The value of Starrett tools is that they are accurate and will last. As the name indicates, this tool can be used for many different purposes - a complete substitute for a whole set of common solid try squares, a 45 degree miter, a depth gauge, a height gauge, a marking or scribing gauge, a level, a plumb and, by withdrawing the blade, it can also be used as a precision rule. This saves littering the workbench with too many tools, each being necessary but may be used less. This results in the goal of all good craftsmen - better accuracy and greater efficiency.