...I'm saying only that the two materials cut to identical dimensions could rarely (if ever) be told apart by most smokers if they were unaware which was which...
Hi georged, I thought about your hypothesis, and the idea can be examined empirically with pipe smokers blindfolded testing out stems with identical specs. For the test, if acrylic stems cannot be filed down so easily, vulcanite or ebonite stems can be shaped thicker to the size of acrylic stems.
Before such an experiment is conducted by anybody, my intuition is acrylic stems can be more comfortable for clenching if the pipe is down to a certain weight which varies across smokers, e.g. a very light Stanwell POTY 2010 in Bing shape made clenching quite bearable. However, my intuition is also that acrylic is harder and therefore less comfortable. This is my personal judgement with my clenching attempts on stems made of different materials, including nylon (Falcon, and some corn cobs I believe) and clay etc. According to (my own personal) clenching comfort I will rate the stem materials as follow:
Nylon > Ebonite / Vulcanite = Horn > Amber > Acrylic > Clay / Ceramic
As example, for a heavier pipe, or due to its shape e.g. a straight pipe, I have to clench on the side with my molars/premolars - and I have to hang onto it harder. With a pipe with ebonite stem, my thinking goes like, "I may make some bite marks onto it, so I have to be easier on it"; in the case of acrylic stem, it is usually like, "hmm.. it is getting painful, I don't want to see my dentist and have her telling me that I chipped my teeth...".