Torque specs are listed as a range because it’s not critical to have an exact torque applied. If it was critical then some sort of quality control spec would also be given. But mostly a range is given so we don’t worry needlessly if we tightened a fastener properly.

Torque is measured as a unit of force acting on a rotating lever of some set length. Remembering that torque is the turning effort or force applied to the fastener to preload it, or place it in tension, and is normally expressed in inch-pounds (in.lb) or foot-pounds (ft.lb). …

Insufficient torque Alternatively, the engine’s vibrations can cause the bolt or nut to come undone, displacing the tensioner. This, in turn, will lead to incorrect belt tension and, eventually, to belt and/or engine damage.

When the joint in question is over-torqued, the flange load can become uneven and weaken the effectiveness of the flange/bolt load. This in turn leads to an increase in blow-out pressure and hydrostatic force, which can cause joint failure.

Though often overlooked, torque specs exist for nearly every nut and bolt on your vehicle. No matter the project or repair, if you are tightening a bolt, the bolt has a specific pressure at which it should be tightened. Torque wrenches are important to ensure a balanced rotation of a component in relation to its axis.

Begin with the formula T = K x U x D x P, where T is the torque, K is a standard representing 1.33, U is the coefficient of friction, D is the diameter of the fasteners, and P is the necessary preload.

Prevailing torque is defined as the driving torque required to overcome friction in a threaded fastening application, which produces no clamp load, or bolt stretch.

HSN Code 7318: Screws, bolts, nuts, coach screws, screw hooks, rivets, cotters, cotter pins, washers, incl.

DETERMINING TORQUE The general equation for bolt load based on applied torque is T = KFiDb where K = torque coefficient. K is a function of the coefficients of friction and collar friction in the joint, and these are based on variables such as surface finish, coatings, and so on.

Plain ASTM A325 bolts, however, possess sufficient ductility to undergo more than one pretensioned installation as suggested in the Guide (Kulak et al., 1987). As a simple rule of thumb, a plain ASTM A325 bolt is suitable for reuse if the nut can be run up the threads by hand.”

The force of gravity is shown in green. For method 1, the torque from the tension is calculated from the full torque equation, multiplying the tension force by the distance the force is along the rod from the hinge, multiplied by the sine of the angle between those two lines.

The Torque/Tension Equation is a method used to estimate the torque/tension relationship in an assembly. T = (K D P)/12 can be used to developt a torque value that will achieve a certain tension or clamp load. T = Torque (ft. -lbs.)