"mike" wrote in message
oups.com...
1 Why is it that the thread on carriage bolts goes the entire length of
the bolt but not on hex bolts?

Because carrage bolts are used with nuts to tighten. Nuts need to be able
to screw the entire length. Hex bolts do not require a nut to be tightened
and do not have to screw all the way in to something that is threaded to
tighten.


2 What are the differences between hardboard, masonite and tempered
masonite?

Commonly all are the name. Masonite is a brand name for hard board.

Tempered hard board is generally differentiated from non tempered by the
green or red stripe on the side of a stack of hard board. If the pieces
have a red stripe they are tempered. A Green stripe indicates non tempered.
With out that stripe one cannot tell by looking which is which as both
varieties differ in color.



Years ago I used tempered masonite and it was hard as nails.
Today when I go into HD and ask for tempered masonite the show me
something that is nowhere near what I had previously used.

Thanks for any and all help.