A micro-torque limiting production tool and subassembly comprises a hollow cylindrically shaped housing in which a combination bit retainer clutch mechanism is supported. The combination bit retainer-clutch mechanism includes a pair of cylindrical drive and driven clutch disks of a plastic composite composed of teflon fluorocarbon and acetal resin, each having a bulbous region and a region supported front to back relative to each other to define a primary braking surface of area .pi.(D5/2).sup.2 where D5 is the diameter of the bulbous region.