I just busted out the torque wrench and tested an Ideal and an AWAB clamp. One Ideal failed at about 3 pounds and one failed at just under 4 pounds. Both AWAB clamps failed at about 8-9 pounds. Reading the scale at that low a torque is hard. So not an "exact" number. My "snap/click" torque wrench does not even go that low so had to use the needle arm torque wrench.....
If I ahd to shoot from the hip I would say safe working torque is somewhere around 1 pound for an Ideal/perforated style and about 2-3 pounds for an AWAB? The AWAB put some pretty good smush on the 1" wet exhaust hose before failing, the Ideal barely dented it. You'd never tighten one as much as I did the AWAB. 8-9 pounds is an unnatural amount of torque on a hose clamp. The Ideal/perf clamp however failed at a level you may go to trying to stop a leak...
I stopped using perforated clamps a long while ago..
I'll try and upload some pics later.
But the real answer is snug it up until you can't twist the hose on the barb easily or until it does not leak but DO NOT over tighten, especially perforated clamps... I used to have a two gallon bucket full of failed perf clamps but I finally got sick of collecting them and brought them in for a coffee & bagles worth of stainless scrap $$$$......