types and usage of sheet metal screws
04/03/2020

Types and Uses of Sheet Metal Screws

Construction industries, HVAC companies, roofing contractors, gutter experts and even DIY enthusiasts need access to the right solutions — whether it be the right power tools or the best set of fasteners. But how do you know if sheet metal screws are your best bet compared to other types?

All Points Fasteners gives you a sheet metal screw definition, along with its different types and how to use them. We provide enough guidance to eliminate the guesswork when you’re deciding between sheet metal screws and what type matches your applications.

Sheet Metal Screw Features

As suggested by its name, a sheet metal screw is often used for sheet metal applications. You can fasten metal pieces to other metal objects, or you can attach metal to another surface like plastic, aluminum, plywood, hard rubber or wood.

The fasteners are fully threaded to increase retention between materials. They have sharp tips and threads to help pierce solid metal surfaces and other sturdy resources.

Sheet metal screws are usually made of stainless steel, which aids in durability and long-term performance levels. This coating feature also helps prevent rust and corrosion from forming over time. You can even opt for zinc-plated fasteners or other coatings that are available, but stainless steel is the most common.

Classification

Sheet metal screws are categorized by three numbers that represent the screw’s diameter, length and thread count. The diameter, or size, is indicated with a number between zero and 24 to describe the shaft and head diameter. The length represents the measurement of the entire screw. Each fastener also has a pitch that indicates the number of threads per inch of a fastener’s length.

For example, a screw that reads 8-32 x 1 indicates it’s a size 8 with 32 threads per inch and is 1 inch long. Sheet metal screw sizes will vary depending on your project, material and whether you require a pre-drilled hole.

Sheet Metal Screw Types

Like any hardware, fasteners are available in different materials, lengths and gauges. They also have different point, head and slot variations. The two main types of sheet metal screws are self-tapping and self-drilling, each having many features to choose from.

Self-tapping screws are ideal for jobs that have pre-drilled holes. The screws often have sharp tips to drive the screw through the metal. The technique of using a pilot hole helps prevent the splitting of the material, creating a more seamless finish.

Self-drilling sheet metal screws have a tip that’s more like a drill point to penetrate metal without the need for a pilot hole. It helps preserve the integrity of the material by avoiding denting. You can fit the screw to your drill bit and drive it into a surface.

Which type and features you need will depend on the task at hand. The point, head and slot type of sheet metal screws work for a variety of jobs in every industry.

Point Type

Sheet metal screws are available in three point types.

  • Type A screws have coarse threads and gimlet points that are used in thin metals and wood.
  • Type AB is a fine thread screw, also with gimlet points. AB fasteners are ideal for more fragile materials, producing a wider range of applications compared to Type A.
  • Type B has blunt tips and spaced threads for plastics and plywood, as well as thinner metals.

Head Type

Each sheet metal screw also has varying head types — flat, hex, hex washer, oval, pan and truss.

Based on the requirements of your job, do you need the screw to be flush against another surface? Or, will your project do well with a screw that sits above?

  • Flat: A flat head has a Phillips or slotted style that provides an ideal countersink for various materials, which means it rests below the surface. A flat head design features self-drilling options with a drill point at the tip of the fastener.
  • Hex: A hex has a hexagonal head that’s often used with a nut to make a secure attachment.
  • Hex washer: hex washer is a secondary name used for sheet metal screws. Like the hex, it has a hexagonal head, but it also has a washer to secure the screw’s shaft to the material.
  • Oval: An oval sheet metal screw head is like a flat head screw. However, it has more girdles on the top to provide a finished look. The head sits flush against a surface for a reduction in wind resistance and enhances installation. You can use a Phillips or slotted screwdriver.
  • Pan: A pan head type is rounded and protrudes above a surface when the installation is complete. It features a Phillips or slotted-head variation. A pan head also has self-drilling options with a drill point at the tip of the fastener. Along with a stainless steel or zinc coating, a pan can also be white or black-coated.
  • Truss: A truss has a wider head and rounded top with a Phillips style slot.

Slot Type

sheet metal screw slot type

Depending on the tools you have available, you may be able to work with all three slots — cross, slotted and square.

  • Cross: A cross, also known as a double slot, has two slits perpendicular to each other. You can use a use a slotted or Philips screwdriver.
  • Slotted: Known as the original slot type, slotted versions have a single slit down the center of the screw head. You can use a flathead screwdriver to tighten the fastener.
  • Square: A square type is recessed, making it resistant to slipping when you’re screwing.

Figure out which point, head and slot type best suit your projects, whether you work in the construction, gutter or roofing industries.

How to Use Sheet Metal Screws

Uses of sheet metal screws can differ if you’re working with sheet metal one day and attaching metal to a plywood surface the next. Always start with the right protective gear for any hardware project. For example, eyewear will shield your eyes from metal shavings and other potential hazards.

Be careful not to over-tighten the screws because you can strip the heads or damage the material.

  1. Select a power drill or screwdriver.
  2. Choose the right size screw.
  3. Select the ideal material.
  4. Determine the right head style.
  5. Pick between pilot-hole screws and self-drilling screws.
  6. Clamp together the two objects you need to fasten.
  7. Press the screw firmly onto the surface, making sure it doesn’t spin and stray from the desired point.
  8. Begin drilling at a low speed.
  9. When the sheet metal screw starts to pierce the material, speed up the drill.
  10. Don’t continue to drill once it’s tight because you will strip the slots.
  11. Drilling too tight can also stretch out the screw’s threads and cause it to lose optimum strength.

Once you have all the supplies you need, make sure to drill slowly with precision and caution. Operating too fast can split the sheet metal or cause other damage to the material. If you need further help understanding which is best for your jobs, rely on the professionals for advice.

The Fastener Experts Have You Covered

contact all points fasteners

All Points Fasteners is a fastener distributor that goes the extra mile to chase down what you need. We provide sheet metal screw solutions and even find uncommon fasteners when your projects rely on unique results. Our specialists will suggest what premium parts will work best for your applications to keep your operations running. We are American owned and operated, striving to build long-term relationships with your company.

Browse our inventory of sheet metal screws or reach out to our service team online for support. You can also call us at 800-483-6354. All Points offers a live chat to help you find the right part for the job, too.