Fretsaw

The fretsaw is a saw used for intricate cutting work which often incorporate tight curves. Although the coping saw is often used for similar work, the fretsaw is capable of much tighter radii and more delicate work. It has a distinctive appearance due to the depth of its frame (typically between 10 and 20 inches), which coupled with the comparatively short five inch blade makes this tool appear somewhat out of proportion compared to most other saws.

Compared to the coping saw it has much shallower blades, which are usually extra-fine (up to 32 tpi). This allows much tighter curves to be cut - with many blades even sharp corners are possible - but the blades are also much more fragile compared to that of a coping saw. Unlike the coping saw, the blade has a fixed orientation in relation to the frame. This means that the fretsaw is less useful when cutting long narrow components, but the increased depth of the frame does allow access much further from the edge of the board.

It can be appreciated from the photograph accompanying this article that the frame makes up a large proportion of the total weight of the tool and has a relatively large moment, which in the hands of an inexperienced user can create a tendency for the direction of cut to drift away from that desired. To counter this the fretsaw is usually used with the handle (and blade) aligned with a vertical axis which reduces the effects of the torque caused by the weight of the frame. The effect may also be lessened with a shorter (and lighter) frame, although this reduces the size of components that may be worked. A cutting table, also known as a V-board, made of either wood or metal and which clamps to the edge of the workbench, may be used to support the workpiece whilst allowing clearance for the sawblade by means of a V-shaped slot cut into it.

The blade is usually clamped into position using a pair of wingnuts. Although wingnuts are usually intended for operation without tools it is often impossible to apply sufficient force purely by hand. Wingnut spanners (US English: wrenches) greatly increase the torque that may be applied, ensuring that the blade is securely clamped.

Although traditionally intended for woodwork, metal cutting blades are readily available increasing the flexibility of this saw. Spiral blades are also available which have teeth on all sides of the blade, and will cut in any direction without the need to rotate either the saw or the workpiece. This can be useful when access is restricted due to the size of the component being worked, and compensate in part for the inability to rotate the blade in the manner possible with a coping saw, but they do remove more material than a normal blade. Together these blades make the fretsaw suitable for many tasks traditionally performed by the piercing saw, although piercing saw blades are typically finer than even the finest fretsaw blade.

The fretsaw is similar in many respects to the scrollsaw, which is essentially a powered fretsaw with a table. Blades between the two tools are usually interchangable, and indeed scrollsaws are often known as "fretsaws" informally.

The tool takes its name from its use in fretwork and ultimately from the French "freter" (lattice) - a reference to the intricate patterns often created using this tool. [cite book |title=The Oxford English Dictionary |publisher=Oxford University Press ]