Torque Settings

I can't give you exact answers but I can tell you this: the torque required will vary with the thickness of the chassis material and its hardness. You also need to take into account what is being fixed to the chassis.

I'd suggest either contracting a suitable mech engineer for a day or doing a bit of trial and error: use a test chassis, drill a row of pilot holes, insert screw and torque down at a low setting; Increase torque for next one. When you find one that either damages what's being fixed down or strips the thread, back off a couple of steps and try 1/2 dozen more at that setting, just to be sure.

If the product is liable to be subject to vibration (including delivery, transport by purchaser, etc) then you'd need to check that the fasteners can cope with that as well.

The whole field of fastener torque is a minefield - try a Google search and you'll see what I mean!