• Tool WallImage by Flickr.com, courtesy of Lenore Edman
  
  

History

• Laroy Sunderland Starrett first patented the combination square in 1883.
  
  

Description

• Typically, a combination square has a headpiece with two or more angles and a level to ensure the wood measurement is plumb and even.
  
  

Features

• The headpiece has two flat surfaces--one 45-degrees and the other 90-degrees--that attach to a ruled blade with a thumbscrew. This ruled blade is usually 12 inches, but some models are longer.
  
  

Function

• The combination square lays parallel to the wood to measure 90- or 45-degree angles. Woodworkers use the 45-degree when making a miter joint. Additionally, its ruler provides a straight and level surface for measuring and marking lines.
  
  

Fun Fact

• While there have been some minor attempts to improve on the original design, such as removing the rib, the combination square has remained relatively unchanged.