The JET JWP 15B is the smallest of JET’s two stationary thickness planers. It comes in a version with straight blades (JWP-15B) and one with a spiral cutterhead (called JWP-15BHH, with HH for Helical Head). The JET JWP-208-1 is its larger brother.
The 15BHH has 4 rows of 48 spiral cutters, which can be removed individually and turned 90 degrees to use another one of its four sharp sides. It is also much quieter (almost 20 dB according to JET’s own tests). In addition, spiral cutters tend to also give better planing results, especially with twisting/difficult grain.
There are a few other differences between the two models. The Helical Head model is slightly heavier, probably because its infeed and outfeed tables are made from cast iron while those on the 15B are steel. The steel tables are also slightly shorter. The planer table is made from cast iron on both models.
Both models have two speed rates: 4.9 and 6.1 m/min (16 and 20 ft/min) which allows you to slow down when dealing with difficult grain or increase speed for higher efficiency.