
Aframe saw orsash saw is a type ofsaw which consists of a relatively narrow and flexibleblade held under tension within a (generally wooden) rectangular frame (also called a sash or gate). They are used for cuttingwood orstone. The blade is held perpendicular to the plane of the frame, so that the material being cut passes through the center of the frame. Frame saws for use with wood arerip saws operated as ahand saw or powered in asawmill. Frame saws used for cutting stone were powered saws in stone mills.
When used for different purposes, a frame saw may have other names. For converting logs intolumber, they are also called a pit-saw orwhipsaw. For sawing veneer, they may simply be called aveneer saw. It is unknown how early framed pit-saws came into use; however, there is an Italianfresco fromc. 1300 depicting their use.
A more modern development from the 18th century is theopen pit saw which resembled a large hand saw with no frame, atill for ahandle at the top and abox for a lower handle. This form of pit saw is still manufactured and in use in rural areas ofdeveloping countries as a means of processing timber.
The frame pit saw was the mainstay of resawing before stiff, unframed two-man saws called a muley or mulay saw,circular saws, andband saws took over. In some earlysawmills a frame saw was powered from awater wheel,wind mill or other rotary motion through acrankshaft andconnecting rod. Frame saws are now largely obsolete, althoughwoodworkers who eschewpower tools still make them for personal use in many sizes and styles of assembly.