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 Starrett name has always been associated with squares because our founder, Laroy Starrett, invented the combination square in 1877.The success of this tool led to the beginning of The L.S. Starrett Company in 1880. The combination square is one of the world's most practical and versatile tool inventions – the basic tool for every builder and craftsman. Squares In this section you will see combination squares, solid test or try squares, and special squares for tool and diemakers and carpenters. To check squareness at the highest level of accuracy, we recommend our TS True Squares.These are available in three styles down to the amazing accuracy of 1/4 second. These are listed in the Gage Block Section of this catalog. We also offer granite squares which are listed in the Granite Surface Plate Section of this catalog.The main purpose of these squares is for checking the X,Y, and Z axes on CNC machine tools and coordinate measuring machines. Tips for Using Squares and Center Heads First, make sure your square is clean and that it is located against a flat surface – burrs on metal or knots and bumps on wood will throw squareness off. Second, to scribe a line, the steel scriber can be used on any material, but usually on metal. A carpenter's pencil is normally used on wood, but if finer lines are needed, a light cut with a utility knife may be used.This is also handy when scribing cross grain. Third, when using a center head on a piece that may not be completely round, it is good practice to scribe more than two intersecting lines . Squares Combina tion Squares Fea ture: • A choice of smooth-finished forged and hardened (longer wearing) steel square head and center head, or a cast iron square head and center head.All bearing surfaces are accurately ground. • A choice of stable cast iron protractors – reversible or non-reversible style – all nicely finished with a black, durable finish • Protractors are furnished as reversible, with shoulders on both sides of the blade, or non-reversible, with a single shoulder on one side of the blade only. All protractors also have a spirit level. • Protractor heads have revolving turrets with direct- reading double graduations, 0-180º in opposite directions. This permits the direct reading of angles and supplementary angles. • Most square heads have a handy spirit level and a hardened scriber • Square blades and protractor heads come in a choice of regular or Starrett no-glare satin chrome finish • 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 blades feature easy-to-read,sharp graduations and are available in many convenient styles • Separate parts and attachments available 266 S quares