Building Fasteners FAQ | Coarse Versus Fine Threads

Experts in the fastener industry often engage in a debate over which is better, fine threads versus coarse threads. There are pros and cons for each thread type and many professionals prefer building fasteners with a certain thread, as opposed to the other. Examine the differences and decide for yourself.
Pros and Cons of Fine Threads
Many fastener experts agree that fine threads provide a higher level of strength in tension, due to the fact that building fasteners with a fine thread have a more substantial tensile strength. Fine threads are not as strong in terms of stripping.
Building fasteners with fine threads are designed with a larger minor diameter, which in turn develops greater torsional and traverse shear strengths. They are also easier to tap into both hard and thin-walled materials. Fine threads also provide a smaller helix angle, which then allows for closer adjustment accuracy.
Fine threads are more prone to damage during the shipping phase. And in terms of plating and coatings, fine threads can only take a thin layer of treatment before threading adjustments need to be made.

 
Pros and Cons of Coarse Threads
Building fasteners with coarse threads are very common and deliver a host of benefits. They strip less often, particularly in the sensitive internal threads. Coarse threads also tend to deliver a higher resistance to fatigue.
Coarse threads are better when working with a brittle material or one that may break apart under the threads. While they may not work as well in hard materials, coarse threads also tend to develop cross threads less often. Contractors find that assembly and disassembly tend to go quicker with coarse threads.
Coarsely threaded building fasteners often arrive with less shipping damage. This results in less waste for the middleman, as well as fewer returns on the retailer’s end.
Not the strongest choice in tension, coarse threads have nevertheless gained in popularity over the last few decades. They tend to be less expensive to manufacture, making them a more cost effective choice. Unless a fine thread is specified, or the contractor prefers a fine thread, coarse threaded building fasteners will be chosen more often than not.