Self-drilling screws – commonly known as Tek screws – are some of the most widely used metal fasteners in the building and construction industry.

Tek screws or self-drilling screws come with an additional pair of bladed flutes which extends from the threaded portion of the body all the way to the drilling tip.  The purpose of this is to combine the drilling and tapping function onto the same screw, thus eliminating the need to pre-drill pilot holes and tap threads.  Drill, tap and fasten are completed in one go, saving time and money.  The best Tek screws come with various types of surface treatments to cope with the environment and provide weathering resistance to itself and the fastened substrate.

Tek screws are popular for many general sheet metal applications like roofing, cladding, and HVAC, etc.

Larger Tek screws (No.3 Tek and above) are strong enough to penetrate 12~20-gauge galvanized steel, as well as 3/8” to ½” (10~12.5 mm) structural steel and can be used on various civil and naval engineering applications.

What is the best way to use Tek Screws?

To ensure optimum use and extended lifetime, here are some tips and recommendations for fastening Tek screws successfully onto various kinds of metal material.

  • Choose the right size Tek screw to match the material you are working with.
    Make sure that the Tek screw drill point capacity exceeds the thickness of the material to be drilled.  Failing to do so may result in burnt out or broken drilling tips.
  • Power drills with adjustable clutch settings are better suited for use with Tek screws on light sheet metal than Impact drills.
    The hammering action generated by impact drills can cause metal dimpling or oil canning deformations on lightweight metal sheets.
  • Do not overtighten the Tek screw and washer when fastening them onto sheet metal. The washers should be compressed just enough to fill any uneven surface to provide a perfect seal.
    Two things can happen if the washers are over-compressed. One, the sheet panel may deform from overtightening, and two, the exposed portion will be exposed to the sun and the elements, which accelerates the weathering process and reduces lifespan.
  • When fastening Tek screws onto hardened galvanized or structural steel, set your (cordless) power drill clutch speed to approx. 1500 rpm, and apply steady, consistent, pressure throughout the process.
    Drill speed exceeding 2300 rpm or more can result in premature drill point wear or burnout, causing it to lose its function.

Do not compromise the quality and workmanship of your construction projects.  Your building is only as strong as its weakest fastener.  Choose only quality self-drilling screws from a reliable Tek screw manufacturer – Choose BDN Fasteners today, every day.

Despite their widespread availability and usage in commercial, industrial, and construction applications, many still confuse self-tapping screws with self-drilling screws.

Part of the reason this happens is that self-drilling screws are a subtype of self-tapping screws.

Let’s go through these two products separately to clarify these differences.

Self-Tapping Screws

Self-tapping screws have various names. They’re often called metal screws, sheet metal screws, tapping screws, or tapper screws.

Their tips come in different shapes: pointed (like a pencil), blunt, or flat, and they are described as thread-forming, thread-cutting, or thread rolling. If the screw is pointed, it will be thread-cutting – tapping and creating threads in a pre-drilled hole. If the tip is flat, it is thread-rolling – rolling or extruding threads and creating zero clearance between screw and material.

The most important difference between self-tapping and self-drilling screws is that self-tapping screws cannot go through metal without a pilot hole, which must be pre-drilled or pre-punched.

Exact drill or punch hole size is also important. The screw will become loose and not thread properly and securely if the hole’s too big. If the hole’s too small, the screw can break or cause the material to split or crack.

Self-tapping screws are good for use with metals, various types of plastics (plywood, fiberglass, polycarbonates), and cast or forged material, like iron, aluminum, brass or bronze. Self-tapping screws also work for surfaces where you can’t secure the rear end with a nut. Common applications include fastening aluminum sections, attaching metal brackets onto wood, or inserting screws into plastic housings.

Self-Drilling Screws

Self-drilling screws are easy to distinguish if you look at their point, which curves gently at the end and is shaped like a twist drill. They’re often called Tek Screws, after the brand name that popularized them.

Screw lengths vary, but drill points are standardized, identifiable by number (1 to 5), which determines their length and thickness. Head and drive styles vary; self-drilling screws are most commonly Phillips, hex, or square.

Unlike self-tapping screws, self-drilling screws need no pilot hole to cut and fasten; they can drill, tap, and fasten in one go, which saves you the extra step of drilling, then fastening.

These screws can fasten metal to metal, wood to metal, and work well with light, low-density materials. In general, they have more specialized applications than self-tapping screws. They are good for metal building and light gauge metal assemblies; Point #5 is already capable of fastening half-inch steel sheets.

Self-drilling screws are useful in HVAC applications, cladding, metal roofing, steel framing, and other general construction tasks.

Similarities and Differences

What’s most similar about these two types of screws is that both form threads as they penetrate the material being worked with. Both attach steel on steel and steel on wood when rivets or nuts and bolts cannot do the job.

Between these two, however, self-drilling screws offer two distinct advantages: time and costs saved at assembly time, and reduced error in installation, which often happens if one pre-drills holes in the wrong size.

Consult with self-drilling screw manufacturers you can trust – contact BDN Fasteners today.

Fastening sheet metal is a technical process that not only requires expertise, but also the most optimal screws – specifically self-drilling sheet metal screws. These screws feature sharp threaded shanks and tips that pierce easily through solid metal surfaces and other sturdy materials.

Self-drilling sheet metal screws come with pointed drilling tips designed to penetrate metal without the need for pre-drilled pilot holes.

Without the need for pilot holes, self-drilling screws save installation time, eliminates the extra cost for labor and drill bits. This cost-saving feature and additional advantages make them an excellent choice for metal building construction.

Features to Look Out for When Purchasing Self-Drilling Sheet Metal Screws

Like any hardware, self-drilling sheet metal screws come with various features. But whatever type of self-drilling sheet metal screw you need for your project, it’s best to go for screws that have:

  • Corrosion-Resistant capability

As many tradies know, rusty screws are a real pain to deal with, not to mention an eyesore. Rust significantly reduces the strength of metal structural elements, reducing the thickness, and even leaving holes in components. It is also difficult to contain rust once it starts to spread, which is why self-drilling sheet metal screws with Corrosion-Resistant capabilities are in high demand.

As part of our quality assurance policy, all BDN Fasteners self-drilling screws are sent to SGS for regular Kesternich (7 cycles) and Spray Salt Tests (1000hrs).  Going through regular testing demonstrates our commitment to quality and the results prove consistent product quality.

  • Corrosion-Resistant surface treatment

Self-drilling sheet metal screws with proper Corrosion-Resistant surface treatments last longer against the deteriorating effects that occur from weathering.  Such exposure can negatively affect the performance of various components and increase the possibility of failure in the long term.

BDN Fasteners self-drilling sheet metal screws come with Class 3 Corrosion-Resistant coating – designed to cope with even the most challenging of environments.

  • Corrosion-Resistant accessories

Self-drilling sheet metal screws should also come with accessories that prevent the possibility of rust.  BDN Fasteners self-drilling screws come with optional pre-assembled weatherproof washers such as DEKS Dekseal® Trueblue®, 100% weather sealed washers.  These washers provide the perfect seal between the screw and sheet metal, are anti-static to reduce the possibility of rust, and come with a 20-year warranty that will outlast the life of most sheets – a must for construction projects.

Find High-Quality Corrosion-Resistant Sheet Metal Screws at BDN Fasteners

At BDN Fasteners, we say that your sheet metal is only as long-lasting as the fasteners it is affixed to, which makes all the difference between a good or mediocre project.

BDN Fasteners offer an extensive range of Corrosion-Resistant self-drilling sheet metal screws in various lengths, sizes, and specifications, suitable for a host of applications.

Special features of our self-drilling sheet metal screws include:

  • Patented Trident Self-Drilling Point.
  • Designed to work with DEKS Dekseal® Trueblue® 100% Weather-Sealed Washers.
  • AS3566 Class 3 Corrosion-Resistant surface treatment.
  • SGS Certified: 1000hrs Spray Salt Test and 7 Kesternich Cycles.

As a leading supplier of sheet metal screws in Asia, we maintain strong relationships with dealers, distributors, and project managers, providing the correct fastening solutions for their needs.

For more information and inquiries about our products, contact us today.