Tapping screws, acting upon materials into which they are driven, create mating threads in those materials. The two standard types of tapping screws are thread forming screws and thread cutting screws. At ITW Shakeproof Industrial, as a leader among thread forming screw manufacturers, we are your premier source for thread forming screws and other fasteners and washers to meet your industrial application needs.
Thread Forming Screws
A thread forming screw dislocates material around the pilot hole such that it flows around the threads of the screw. These screws are ideal when the application requires high stresses to strengthen loosening resistance. Since no material is eliminated, the mating component produces a zero clearance fit. Thread forming screws often do not require locking devices, such as lock washers, to prevent loosening.
Thread Cutting (or Thread Tapping) Screws
Thread tapping screws for plastic or metal consist of chip cavities and cutting edges that produce a mating thread. They do this by eliminating material from the component into which they are driven. The cutting action of these screws translates into a low level of torque required for insertion. These screws are ideal for materials when too much driving torque is needed for thread forming screws or where disruptive internal stresses are not desired.
Generally speaking, tapping screws allow quick insertion since there are no nuts used and only one side of the joint is required for access. These tapping screws produce mating threads that fit the screws heads very closely, eliminating the need for clearance. This close fit usually preserves the tightness of the screw, even under vibrating conditions.
Thread tapping or cutting screws are often case hardened with a minimum tensile strength of 100,000 psi and high ultimate torsional strength. These screws may be used in aluminum, steel, cast iron, die-castings, plastics and reinforced plastics, forgings, and plywood impregnated with resin.
Thread cutting screws may come with fine or course threads. Fine threads are recommended if the applications calls for the full thread engagement to be higher than the cutting slot, with the material lacking sufficient thickness to permit two complete threads of course threads.
For more information about the plastic, metal, and sheet metal thread forming screws we offer at ITW Shakeproof Industrial, give us a call today at 920.261.2652 or send us a message through our contact form.