I’ve described the Shelton No.18 on a previous blog post ,so I won’t go over the details again.
The fact that it appeared in the mid 1940s suggests that it was attempting to offer a low-cost alternative to cast block planes, like its predecessor. A case in point is the use of aluminum for the finger, lever cap, and depth adjustment knobs. Such parts are easy to cast in aluminum, as opposed to being milled.
This however sometimes leads to problems of joining parts, such as where the finger knob attaches to the plane body – this often detaches. Unlike the other pressed-steel block planes which have a pressed-steel lever cap, the Shelton No.18 has a cast steel lever cap, giving the plane more heft.
The hand-y on this plane is also cheaper, being only circular holes, without apparent bevelling.
Also unlike the frogs of many of its brethren, the Shelton No.18 has a rather flimsy structure, spot-welded to the plane body.