Sheet Metal Screws
Sheet metal screws are specialized fasteners that feature fully threaded shanks and sharp tips that facilitate screwing into metal. Some are self-drilling, while others require a pre-drilled hole. There are many subtypes of metal screws. This article will offer a comprehensive introduction to what customers need to know before buying metal screws.
Self-Drilling vs. Self-Tapping Screws
Self-tapping screws require a pre-drilled hole. They have sharp tips and require only a pilot hole. While it's sometimes possible to screw self-tapping screws into metal without a pre-drilled pilot hole, it can cause problems with splitting.
Self-drilling metal screws have sharp tips that resemble drill points. They're designed to penetrate metal without requiring pilot holes. Just fit the screw to the drill bit and drive it in.
Metal screws all have one of three point types. Type A features gimlet points and coarse threads. They're perfect for screwing into thin metals and wood. Type AB has a finer thread, but still features gimlet points. They're used for fragile materials. Type B screws have blunt tips and spaced threads and are used for thin metals.
Metal screws come with the same variety of head types as regular wood screws. Choosing the right head type requires consideration of two main factors: whether the screw will need to be flush against the surface, and what bits are available for driving it.
Flat Head Screws
Flat head screws have Phillips or slotted-style heads designed to create a countersink. They're perfect for applications where the screw head must sit below the surface of the material.
Hex screws have hexagonal heads. They're typically used in conjunction with a nut to create secure attachments. Hex washers are also available to further secure the screw's shaft.
The head on an oval screw is similar to that of a flat head, but its additional girdles create a more finished appearance. They're designed to sit flush against the surface.
Pan Head Screws
Pan head screws protrude from the material following installation. They come in both Phillips head and slotted-head varieties, and may be either self-drilling or self-tapping.
Truss screws have wide heads with rounded tops that feature Phillips head slots. They sit above the surface after installation.
There are three slot types for metal roofing screws. Choosing the right one is a simple matter of checking the equipment to see what it allows.
Often referred to simply as slotted screws, this type of fastener is intended for use with flathead screwdrivers or drill bits. They feature one single slit in the center of the screw head.
Cross slots are designed for use with slotted or Phillips head screwdrivers and drill bits. They offer more traction than original slotted screws, making it easier to avoid slippage.
Square slots are fully recessed into the screw head. They're highly resistant to slipping but require specialized drill bits for installation and removal. They can't be removed with conventional screwdrivers.
Choose the Right Screws for the Job
Still not sure exactly what screws will be the best fit? Get in touch with a customer service representative. He or she will be happy to help buyers find the products that best suit their unique applications.