Clean the dust off the siding caulk around the perimeter of the hole then slide your hose bib in and use two 2 stainless steel screws to hold it on.
Attaching hose bib to metal siding.
The hole saw will likely be dull by the time you are done drilling.
Personally i would not use a latex caulking on fiber cement.
Most hooks are stainless steel so they won t corrode and they are easy to remove when you re done with them.
The easiest and safest way to hang something from vinyl siding is to use a siding hook.
Press your bit into the siding that covers the outside of the house just far enough that it makes a hole with the centering part of the paddle bit.
From the outside slip on the plastic gasket and push the hose bib through the hole.
My main tool for perfection.
Predrill a pilot hole for the screws with an 1 8 masonry bit.
Apply silicone caulk around the hole and attach the hose bib by driving two deck screws that are coated to resist rusting.
This video shows a unique and ez way to mark and cut out an electrical box hole in metal siding.
Drive the appropriate screws through the screw holes and into the wall until they are snug.