Classes of Saw Cuts

If you have ever been disappointed by your results when hand sawing a joint, the problem could be that you are going about the task in the wrong manner. While sawing requires practice, it also is helped along by a few clever and quick tricks.Years ago I read an English woodworking book that separated all sawing into three kinds of cuts: first-, second- and third-class saw cuts. Each type of cut has a different purpose. Third class sawing is for removing material with little regard for accuracy or appearance. Second class sawing is for cuts that require accuracy, but the final appearance of the cut isn't critical. And first class sawing is for situations in which the appearance of the completed kerf is paramount. Third-Class Saw Cuts This type of cut is fast, rudimentary and useful when breaking down rough lumber into manageable pieces. Use it only when the board is going to be refined further; for instance, in circumstances where you will shoot the ends with a plane or crosscut the board to a finished length with a powered saw or finer handsaw. Begin by marking the cut-line on the face and edge of your board with a pencil. Place the teeth of your saw on the waste side of your line and use your thumb to keep the saw positioned as you make your initial strokes to define your kerf. Advance on the face and edge of your board simultaneously to increase your accuracy. Saw rapidly through the board until you get near the end of your cut. Then use lighter and shorter strokes to cut the waste away cleanly. Third class sawing: A good sawyer can split a pencil line even with a rough cut such as this. However, accuracy isn't as important as cutting the wood to size as quickly as possible. Second-Class Saw Cuts This class of cut is used when accuracy is important, such as when sawing the cheeks of a tenon or a lapped dovetail joint inside a case piece. The results of your cut will be buried in the mortise or in the dovetail socket, so appearance isn't of primary importance. Begin by marking your cut with a knife all around your work. Then, at the corner where you will begin your cut, place a chisel in your knife line with the bevel of the chisel facing the waste. Press the chisel into the work, remove the chisel and then come back and pare a triangle of waste that leads up to that corner. Now place your saw in this notch and begin cutting. The notch ensures you begin the cut correctly, which is the most difficult part of sawing. Second class sawing: Place the bevel of the chisel toward the waste and press the tool in. A 1/16" or 3/32" depth of cut will do. Remove waste at the corner: Pare away a triangular wedge of material. This notch helps start your saw accurately. Sawing true: If you begin a saw cut in the right place, your chances of finishing in the right place increase. First Class Sawing This type of sawing is best for parts of the joint that will be visible on the finished piece, such as the shoulder cut on a tenon or half-lap joint. It requires a couple of extra steps, but the results are worth it.

First mark your cut-line with a marking knife on all surfaces that will be cut. Then take a wide chisel and place the tool's edge into your knife line with the bevel facing the waste. Rap the handle of the chisel to drive it into the knife line all around the joint. Remove the chisel and then pare away a wedge-shaped piece of wood on the waste side, working up to your now-widened knife line. The second chisel cut must be deep enough so that the set of your saw's teeth is below the face of your work. Secure your work to the bench. Place your saw into the chiseled notch and make the cut. By using a chisel to define the kerf of your saw, you eliminate the common problem of the saw's teeth tearing at the surface of your work.

Widen all knife lines: Place your chisel's edge into your knife line and tap the handle to drive the edge into your work, widening the "V" left by your knife.

Pare all around: With the bevel of your chisel facing up, pare a wedge-shaped piece of waste away on the waste side of the joint.		Sawing is simpler: The chiseled notch guides your saw and eliminates any torn grain from the face of your work.
Christopher Schwarz, Editor, Popular Woodworking magazine