What is Torque?
Torque, in essence, refers to a twisting force. When you wind your watch, torque is applied to the watch stem. Similarly, when unscrewing the top of a mason jar, you exert torque. This force induces the rotation of a shaft or establishes a twist in a stationary shaft. Torque is typically quantified in foot pounds or inch pounds.
How is Torque Determined?
To ascertain torque, consider a shaft connected to a 2 ft. lever or arm that necessitates 2 lbs. of applied force to initiate rotation. In this scenario, the torque would be 4 ft. lbs. The torque formula is expressed as T = R x S, where R represents the radius or length of the lever, and S stands for pounds pull on the scale. Threaded products derive their holding power from the tension (or torque) generated through the mating of external and internal threads, subject to the elastic limit of the material.
What Torque to Apply?
Determining the appropriate torque to apply is a common inquiry, yet the answer hinges on several variables, including material, threads' class of fit, method of thread manufacture, and thread lubrication (if any). The Technical Information PDF linked on this page provides a table suggesting maximum torque values for threaded products crafted from corrosion-resistant metals. It is essential to note that this table serves as a guide. The values indicated, except for Nylon, represent safe working torque. In the case of Nylon, the figures denote breaking torque. Actual tests were conducted on dry or nearly dry products, and mating parts were meticulously cleaned.