A number of woodworking projects call for dowels or tenons that need to be cut off at surface level. Most power saws cannot provide such a flush cut, and standard hand saws are not flexible enough to remain level with the wood's surface without causing damage from their offset teeth. Woodworkers and carpenters often use a flush-cutting saw to cut off protruding dowels, rods and exposed tenons. This type of saw has a flexible blade and teeth that only cut on the pull stroke.
The Japanese flush-cutting saw is considered an indispensable tool for advanced woodworking projects. Since its introduction, other countries have produced similar models of the saw. Each one may have some minor differences, such as the number of teeth per inch (tpi) or the flexibility of the blade.
The average tpi count of a flush-cutting saw is around 19 to 22. The teeth do not offset each other as those of a cross-cut saw do. Instead, the teeth curl back towards the handle, which means that they only cut on the pull stroke, not the push stroke.
A flush-cutting saw looks something like a paint spatula, with a long, squared-off blade coming out of a handle. It may have one or two sides containing teeth – the two-bladed model is ideal for both left and right side cuts. There is also a "This Side Up" notation to keep the saw oriented properly. Sawing with the blade upside-down can cause damage to the piece, since the teeth will dig into the wood in that position. The blade is relatively flexible, which means the cutting area will stay level, or flush, with the surface as the dowel or tenon is sawn off.
When using a flush-cutting saw, the woodworker should clamp down the piece for security. He can then place the blade of the flush-cutting saw near the dowel or tenon to be sawn off. The blade should lie flat on the project as the woodworker flexes the blade upward.
Although a flush-cutting saw can be used aggressively, it is better to work slowly and steadily. Since the saw only cuts during the pull stroke, the woodworker should not try to remove material on the push stroke. Instead, she should allow the saw to move slightly up and over during the push stroke and to cut through the material on the pull stroke.
If done properly, a cut from a flush-cut saw should require little to no sanding. A quality set of Japanese hand saws can be an expensive investment, but many professional woodworkers say the quality of the cuts cannot be duplicated with standard saws or power tools.