I have been able to find several generic torque tables on the internet, but not one that differentiates between metal on metal, metal on plastic, and plastic on plastic. Does anyone know if these tables exist.
I think you are looking in the wrong place. the information you want is in the material data sheets for the substance in question. not in the torque tables. In some cases you have to calculate the data you need. reason is the materials have varying drag characterisitics. so yo uneed to balance thread size, length, depth against the shear strength, flexibility, plasticity etc vs what you require. Sometimes you can use an insert to improve grip ,such as plasterboard screws, or specialised bolts (whitworth thread/metric headsize)
There are several sources for at least a partial answer to your question.
But your question shows in fact how simplified is the way one looks at torquing. The generic torque is the reason why many assemblies fail since the torque was not adapted to the actual tribological conditions and the loading. The problem is that from case to case one could be confronted with torques varying from 1 to 3. For some more stable conditions you find tables in the documents of fasteners manufacturers especially for metal screws in metalsheets or different palstics (without inserts).
You should consider that torque is NOT the wished value but preload. And an important but often neglected factor is the speed. Some time higher speed can totally compromise the assembly.
Torque Requirements
Re: Torque Requirements
