Lima Bravo

Guys can anyone shed some light on the required torque when mounting to a rocker panel? I've got a pair of Westin ovals I'm looking to slap on and manufacturer is claiming 15-20 ft/lbs torque on the upper nuts.... I am curious if anyone actually reached that number? Seems a bit high to me???? no?? I'm working with a freshly calibrated torque wrench so i'm confident in my numbers when the time comes. Just don't want to go to tight....