Fasteners are must-have for nearly every kind of work, and shall be appropriately selected according to the application location, environment, materials and other factors, otherwise the assembled structures and connections will never be strong and durable.
Nails. Simple and reliable fasteners for permanent connection. They are available in a wide variety of sizes, can be made from steel and other metals (aluminium, brass, bronze, copper) and can be galvanised for protection. Depending on the application, nails can have heads of various shapes (smooth or textured) and rods with helical, longitudinal or transverse grooves for better grip on the surface.
Nails classification by application:
- General-purpose nails used to attach objects to each other
- Small-headed brads which can be easily concealed with a finish layer
- Broad-headed roofing nails for secure fastening of the roof covering
- Finish nails that completely sink into the base material and require no further decoration to make the surface look good
Nuts. As to the shape and design, there can be flat nuts, spring nuts, lock nuts, nuts with external/internal teeth, safety nuts, conical nuts, T-nuts and others. Nuts also differ in diameters, materials and applications.
Nuts classification by application:
- Coupling nuts to connect two male threads
- Flanged nuts with a flange to distribute loads
- Hex nuts which require a wrench to be handled
- Lock nuts to secure other nuts
- Slotted nuts which require a split pin or a wire to be locked
- Square nuts that are less susceptible to getting loose thanks to square heads with larger contact surface
Dowels are used to install threaded fasteners into hard surfaces. There are metal dowels, installation (plastic) dowels and splitting dowels.
Anchors. These can be ceiling anchors, drive anchors, wedge anchors, frame anchors, D-ring or ring anchors, anchors with nuts, fixing anchors, hook anchors, loop anchors, screw anchors, expansion anchors,splitting anchors, threaded anchors, pivoting head anchors, winged anchors, spring anchors, etc. The immense variety of such fasteners allows to choose the most appropriate one for each kind of work.
Bolts and screws. These can be classified by length, diameter, head shape (semicircular, countersunk, semi-countersunk, disk, cylindrical, hex, washer head), thread pitch, material, application and material of manufacture.
Bolt types by shape:
- Shoulder bolts with the threaded part thinner than the unthreaded one
- Foundation bolts with the caps designed so as to facilitate attachment to a flat base
- Wrench cap bolts
Screw types by application:
- Wood screws, coarsely threaded to grip wood
- Metal screws, threaded over the entire length for better engagement with sheet material
- Coupling screws for heavy and strong materials.
- Machine screws to fasten materials with pre-drilled holes.
- Set screws with no cap, capable of holding objects without nuts
Self-tapping screws are themselves capable of boring the materials with no need for pre-drilling, thanks to their material and shape. These can be divided into wood screws and metals screws according to the material they are intended to work with, respectively, and can be of different length, width, diameter and thread pitch.
Self-drilling metal screws can be:
- Self-tapping, with a drill-shaped tip
- Screws for pre-drilled bored in the metal
Self-tapping screw types by application:
- General-purpose screws used to fasten construction elements indoors
- Roofing screws intended to fasten roofing materials. These feature larger caps and anti-leakage pressure discs
Rivets are used to make permanent connections. Can be either threaded or unthreaded, differ in material, size and application.
Studs are cylindrical rods threaded over the entire length or at the ends.
Washers are round discs intended to reinforce bolted joints. Can be classified as hexagonal, square, locking (grovers), cap, crown, flanged. In addition, they differ in diameter, material and application.
According to the thread pitch, there are metric and non-metric (standard) fasteners.