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

Table of Contents:

 

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.

These 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 can be made of stainless steel, which aids in durability and long-term performance levels. However, not all sheet metal screws are stainless steel, and there are other material options to choose from. 410 stainless screws (magnetic) that do not have a protective coating are called passivated. Those that do have a protective coating feature, have extra prevention from surface rust from forming over time.

Classification

Sheet metal screws are categorized by headstyles and three numbers that represent the screw’s diameter, length and thread count. The diameter, or sheet metal screw size, is indicated with a number between zero and 24 to describe the shank, although the most common sizes used by contractors and OEM’s would be 6 to 14. The length is measured differently depending on the head style of the screw; usually, from underneath the head of the screw to the point.  In the case of flat or bugle heads, you would measure the entire length of the screw since it will be embedded in the material in it’s entirety.  Each fastener also has a pitch that indicates the number of threads per inch of a fasteners length.

For example, a screw that reads 8-14×1 indicates it’s a size 8 with 14 threads per inch and is 1 inch long. Sheet metal screw size requirements will vary depending on your project and material.

How Do Sheet Metal Screws Work?

Sheet metal screws typically work best when connecting thinner metal objects or when fastening metal to wood, plastic and other materials.

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 Sheet Metal Screws

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.

The benefits of using these sheet metal fasteners include:

  • Fast installation: The innovative design of self-tapping sheet metal screws can save significant drilling time at the job site. You’ll be able to complete projects such as installing stud frames more quickly than ever. These screws will also allow you to allocate your available resources to other areas of your job site faster.
  • Effective corrosion protection: Rust is a prominent issue when working with any metal fastener. If you choose the corrosion-resistant stainless steel screws, they will combat rust formation and provide a longer lifespan. You’ll also have fewer concerns about the structural integrity of the finished product.
  • Exceptional holding power: Some types of self-tapping sheet metal screws feature an underhead serration, helping to prevent them from backing out of the material.  This is really beneficial if they are being used where there might be vibration of machines and will keep them in place doing their job.
  • Headstyle options: If aesthetics are importan

Self-Drilling Sheet Metal Screws

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.

Some advantages of choosing these screws include:

  • Less prep time: Because these screws don’t require pre-drilling, you can complete jobs faster and reduce your labor costs.
  • Corrosion resistance: Like their self-tapping counterparts, if you choose stainless steel screws, they won’t rust. This makes them an excellent choice for use in wet climates.
  • Less mess: You don’t have to drill pilot holes to install these screws, which means you won’t need to spend extra time cleaning up dust, dirt and debris. 
  • Consistent performance: The flexibility and versatility offered by these sheet metal screws allow you to use them on a wide range of materials and get reliable results.

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 shank 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.

Differences Between Sheet Metal Screws and Wood Screws

While sheet metal screws and wood screws look similar, there are some important differences between the two types. Wood screws have a coarser thread (less threads per inch) than the sharper, tighter threads of the sheet metal versions. Also, sheet metal screws are fully threaded up to their heads vs two-thirds threaded with a smooth shank underneath the head like the wood screws.  This shank allows the two pieces to be pulled together.

Thus, wood screw products are a better option when fastening materials such as plywood and lumber. And, while you can substitute sheet metal screws for lumber projects if you’re in a pinch, wood items do not work and should not be used in metal structures or workpieces.

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.

You can also count on us for reliable support whenever you need it. We are the only online fastener company with a live chat feature, enabling you to get immediate help finding the parts you need.

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.

Head Screw Lady Since 1986! Specializing in breaking down the language barrier between suppliers and end users. During her 35 years working in the fastener industry, MaryLouise has worked directly with end users, contractor’s, OEM’S and DIY, as well working within the import industry, working with fastener manufacturers and distributors. This has given her the unique perspective of having the technical knowledge needed to perform in the fastener world but also be familiar with the needs of end users who don’t necessarily know the fastener jargon or applications to know exactly what they need for their jobs.