mike wrote:
1 Why is it that the thread on carriage bolts goes the entire length of
the bolt but not on hex bolts?
2 What are the differences between hardboard, masonite and tempered
masonite? 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.


Your terminology may be a bit off. The typical
carriage bolts has a rounded head with a square
under it (the square sinks into wood and doesn't
turn so a wrench is need on only one end), the
shank is smooth and not threaded except for the
last inch or so. They are meant to fasten wooden
parts together but to leave a smooth surface that
won't catch clothing or other objects. A smooth
shank is essential to reduce wear; threads the
length of the bolt would work in the hole and chew
up the wood.

Bolts threaded the full length are termed termed
machine screws, machine bolts, stove bolts, etc.
depending on the head and the nut and typically
are used to hold metal parts together. Of course
there are also bolts with a smooth shank and short
length of screw that are used for joining metal parts.


Masonite is a brand of hard board. Untempered has
a waffle weave on one side and a smooth surface on
the other, usually light brown color. Tempered is
similar except the smooth side is usually darker
and is harder due to the heat and pressure used in
tempering. Tempered both sides is usually very
dark, almost black, and very hard, almost all the
way through a 1/4" thickness. I haven't seen the
tempered both sides for some time but it is the
best for the bottom of drawers.