With all due respect, the basis for my position is not related to a crust but is much more elemental. With most materials, the coefficient of static friction is higher than the coefficient of dynamic friction. That is, all else being equal, it takes more force to move an object from rest than it does to keep the now moving object moving. Here are some links that describe some of the fundamental physics of friction.
http://hyperphysics.phy-astr.gsu.edu/hbase/frict.html
http://hyperphysics.phy-astr.gsu.edu/hb ... 2.html#sta
http://hyperphysics.phy-astr.gsu.edu/hb ... 2.html#plo
Therefore, the fastening torque placed on a threaded fastener can only be properly measured while the threaded fastener is in motion and not while it is static. This is why I prefer click-type torque wrenches for most general torquing applications; I can concentrate on maintaining a smooth, constant motion of the torque wrench until the pre-set click is heard and am not distracted from providing the smooth, constant motion to the torque wrench by visually trying to read a pointer and gauge type wrench.
And yes, torque is really not the end-all of what we are trying to accomplish; it is only a predictor of what we want. In torquing a head, we are really trying to provide a predetermined clamping force on the head with respect to the cylinder(s) to prevent leakage. If the head gasket has compressed, paint/powder coating on the head under the fastener has compressed, or other components have taken a set after one or more heat cycles, the clamping force exerted on the head by a fastener may have been reduced, even though a check of the torque on the static fastener shows that the fastener does not move when the specified tightening torque is applied to the fastener (due to the higher coefficient of static friction). However, by slightly loosening the fastener first so that the torque needed to move the fastener from rest is lower than the specified tightening torque for that fastener, then rotating the fastener in a smooth, constant motion until the specified tightening torque is reached, will show that the fastener has now been rotated beyond where it was in the first static position, thereby reestablishing the desired clamping force.
When using a threaded stud and nut combination, assuming no damage to the threaded stud or nut, the desired clamping force from each stud can also be determined by the preload, or stretch, of the stud. In some critical instances, such as connecting rod studs in racing engines, the correct tightness of the nut on the stud is not determined by measuring the tightening torque exerted on the nut, but by measuring the stretch of the stud. This is a more accurate determination of the clamping force exerted by that stud because it is less affected by such factors as threads that are buggered, rusty/corroded, dry/unlubricated, dirty, etc. that reduce the proportion of delivered/measured torque that is actually applied to rotating the nut. However, measurement of the stretch of a fastener is not a practical approach in many instances to determine the clamping force desired from that fastener.
Tightening torque specifications set by design engineers for various threaded fasteners are approximate predictors for obtaining the desired clamping force. When setting these torque ranges for various threaded fasteners, the engineers take into account the type, size and material of the fastener, the materials of the components being clamped, intervening washers, and other factors to determine what torque range most accurately predicts the desired clamping force from that fastener. That torque range becomes an inaccurate predictor of clamping force when the threads are buggered, rusty/corroded, dry/unlubricated, dirty or otherwise contaminated or the mating faces of the threaded fasteners, head or washers have become galled. On the other hand, the desired clamping force may never be reached if threads are on the verge of pulling out or if the bolt/stud is fatigued, cracked or has been stretched beyond elastic deformation to plastic deformation.
To summarize, to properly torque a fastener, make sure the threads are clean, and not deformed or contaminated. Chase or repair the threads if they are damaged. The threads should be lubricated or have anti-seize applied. Excepting for lock nuts, in most instances, the nut or bolt should be able to be tightened by finger up to the point of setting the torque if everything is in proper condition. If not, then a significant part of the specified tightening torque is being lost to friction and is not being used to properly set the desired clamping force. The torque should be set while the fastener is in a smooth, constant motion and the motion only stopped upon reaching the specified tightening torque. If a fastener needs to be retorqued, it should first be loosened to the point where the torque needed to again move it from rest is below the specified tightening torque, then retightened in a smooth, constant motion until the specified tightening torque is reached. This should be done one by one so that any seal between components is not lost by loosening all of the fasteners at once.
Certain high stress applications where the fastener is considered to be one use only may have different requirements, but that doesn’t apply to most Norton head fasteners.