* Carbide Tip CHOPPER blade - choice of 12-inch x 24-tip (recommended) or 14-inch x 30-tip
Why reinvent the wheel. They were designed to be used with the above. To change from the manufacturers recommendations not only voids any warranty work but exposes your department to liability issues should something not go right...
For a warranty to be voided by the manufacturer because of use of aftermarket parts, the manufacturer must prove that said aftermarket part had a direct effect on the product failing. (if I put an aftermarket exhaust on my car, and the steering goes out the warranty MUST be honored)
And use of a tool in the proper way should not expose anyone to liability issues.
We did a series of tests on metal roll-up doors and roofs about a year ago and the Fire Hooks blades cut dozens of doors and roof vent holes with only two blades. One of the blades is still in service today.
The long teeth on the Warthog make it a no-so-good choice for metal doors and roofs. They can bite too deep and catch on the heavier supporting door framework and roof support system. That can violently yank the saw and cause the operator to lose control.
For metal doors and roofs, you need shallow, not deep cuts.