1 The installer no longer has to try to hold hanger, joist and nail with one hand and swing a hammer with the other! 2  JHA270 range features a location tab which allows easier alignment of the hanger.  The model number and size is stamped into the seat of the hanger for easy identification, even after installation.
first class(Adjective) Belonging to the best or top group in a system of classification. first class(Adjective) Of, or relating to the most luxurious and expensive class of accommodation on a train, ship, hotel, etc. first class(Adjective) Of, or relating to a class of mail to be delivered before second class.
The other two, however, directly fall in line with what I would call (oddly enough) classes every mechanical engineer should take. The first class is machining, which should be fairly apparent from my title and picture [photo credit: Smithy].