[deliriousga]

For bolts it's very important. Torque values are set to make sure a bolt is tight enough not to come out, but not so tight it damages the threads or completely strips them. The smaller bolts that are holding two parts together with a gasket sandwiched between them are torqued to make sure the gasket seals properly. Over-torqued can cut or damage the gasket and under-torqued can leave gaps and cause leaks. Bolts that are on spinning or vibrating parts will often have two torques. The first allows the bolts to be evenly tightened around the part, then the second makes sure they tightened to a point where they won't back out.

For small screws, it's about impossible to torque them with regular tools. The torques are mostly set to make sure you don't break plastic parts that are being held with the screw. You just need to make sure you're not allowing the screw to dig into the plastic or metal that it's holding down.