Malco FCS Fiber Cement Hand Snip
Malco Fiber Cement Snip, Designed Specifically making precise arc and trim cuts in fiber cement siding.  This tool is recommended for cutting 5/16" James Hardi and Certainteed Siding products.  Shearing fiber cement products with this tool creates much less dust than sawing or drilling.  Unique ergonomic design allows the user to operate the tool from the bottom of the material.  This way lines and shapes can be marked on the finished side of the panel and easily be followed with the center blade of the tool, which is on the top of the panel.  (See Picture)