How to choose a block plane
They all do the same jobs, but some block planes are easier to use than others as they are more readily adjustable.
Choosing one can be difficult, but the following tips on buying will hopefully make things clearer.
Metal vs. wooden
The primary choice you have to make is between metal and wooden planes.
Wooden block planes
Wooden block planes have a certain appeal, especially as they are made from the material that woodworkers love to work with, but the downside is that they are generally more basic than metal planes and mastering their adjustment can be an art in itself.
Buy a wooden block plane by all means if you are a fan of all things wooden and find knocking in wedges and hammering strike buttons and irons fun rather than daunting procedures.
Remember, though, that you normally can't adjust the mouth opening of a wooden plane. If this places any limitations on the work you want to do, then you might need an adjustable metal plane instead of, or as well as, a wooden one.
Metal block planes
If you prefer a metal plane, unless you're certain you only need a block plane very occasionally for chamfering or small end grain work, go for one that can be easily adjusted for every type of job a block plane does.
That means depth and lateral adjustment mechanisms and an adjustable mouth.
Getting the right angle
The cutting angle of the plane's iron is important if you do a lot a end grain work. Generally, the lower the cutting angle, the easier it is to shear off end grain without undue effort.
As far as the quality of block plane irons is concerned, the thicker they are, the better they perform. The iron should be at least 3mm (1/8") thick and made of O1 or A2 steel.
New vs. second-hand
There are many used metal and wooden block planes for sale on the internet and at some salerooms and second-hand shops. Some planes, even when they're many years old, represent better quality than some of the cheaper planes being made today, although there may be some work involved in setting them up to perfection.
A new, high-quality block plane can be expensive.
However, you might get similar quality in a second-hand block plane for less than a third of the price.