In its simplest form, a block plane has a body, blade, and some form of lever cap to hold the blade in the plane. There are many different renditions of block planes, mostly due to different forms of mechanisms for lateral/depth adjustment, the addition of a mouth adjustment mechanism, or the cost of the plane. Anatomically, less expensive block planes have few adjustment mechanisms, and often the simplest means of holding the blade in place – the fewer the parts, the less costs are involved in the manufacturing process. Yet most block planes can be distilled down to a few basic features.
These pictures show the major parts of a block plane in the context of a Millers Falls No.16.
There is extensive variability amongst differing designs over the past 150 years, however the core ideas remain the same. In general block planes have up to three core adjustment mechanisms, and one clamping mechanisms. Adjustment mechanisms found on block planes include:
- throat adjustment: a mechanism used to adjust a sliding plate at the toe of the plane to increase the size of the block planes throat, and hence the fineness of the cut.
- depth adjustment: a mechanism that allows the depth of the cut to be adjusted.
- lateral adjustment: a mechanism which allows the blade to be adjusted from side-to-side in order to ensure the cutting edge is perpendicular to the length of the plane.