Found easy way to cut hardiplank..
 

I am doing some residing work on my house using hardiplank siding. Nice
stuff, a neighbor has it on his house for 10yrs now, no problems, paint
still looks like new, just recently cleaned. I helped another neighbor
do some at his house using a circular saw. Regular blade made a ton of
dust, cement blade also made a ton of dust..This dust is hazardous to
inhale.
Another neighbor got a set of shears for cutting it. They work great
and look like a heavy duty drill. No dust, fast cuts too. Only problem
it costs $250. Cement cutting blades run about $50 each and you may
need a few. Decided to try my handsaw on it. These have the newer style
sharp teeth and cost about $9. Cuts perfectly. Easy as wood! I even cut
the much thicker Hardie trim with it, slower but doable. I may go thru
a few of these saws but with no dust and good clean cuts and no noise
at a cheap price it works for me. Oh I find that this stuff drills very
nicely also. Since without a nail gun you cant really hammer a nail
since its so hard to start it. I am predrilling the hole and then
nailing it using a hot dipped Galvanized nail approved for it. Works
great, a little slower of course but if you have one to drill, one to
nail it goes pretty fast. Of course a commercial builder would use the
shears and proper nailgun, but the tools would have cost more than the
siding I am repairing...