Toggle bolts use a spring-loaded, wing-like toggle to hold against the back of hollow base materials. To install, insert the bolt through your fixture and thread the toggle onto it. Next, fold the toggle wings flush against the bolt and push them through a drilled hole until they pop open on the other side. Pull back on the bolt and tighten.
Steels are designated by a 4 number SAE Steel grade. The first two digits indicate the primary materials used to form the steel. The last 2 digits identify the percentage of carbon for the alloy (in hundredths). The steel used in these fasteners has a tensile strength ranging from 100,000 to 150,000 psi (pounds per square inch). Zinc Plating helps to prevent corrosion.
Flat head fasteners are designed to fit flush to the surface when used with countersunk holes. Length is measured from the top of the head. Common applications for slotted screws include woodworking, although the drive style is not designed to be used with power drivers.
A threaded fastener's size name includes information about the major external diameter, followed by the threads per inch, which indicates if it is coarse or fine. Coarse threads are better when working with brittle materials; they are sturdier and are easier to thread and unthread compared to fine. Coarse threading also allows for thicker coatings and platings.