No Matter what you may call them, a Self Drilling Screw is a time saver! Self Drilling screws feature a distinct flute or drill point at the end of each screw, as well as self tapping threads to turn a three-step installation into one quick job. The TEK drill point, as well as the self tapping threads of the screw eliminate the need for pilot hole drilling and hole tapping before screw installation. Self Drilling Screws are used primarily when fastening into steel or other metals, and are typically used to join materials like sheet metal. Self Drilling Screws are primarily made of harder metals, or treated to make the material harder. Typical materials include hardened Zinc Plated Steel, and 410 Stainless Steel. This is to ensure that the drill point is a harder metal than that into which the screw is being installed. 410 Stainless Steel is ideal for Self Drilling Screws because it maintains the corrosion resistant properties of standard 18-8 Stainless, but can be heat-treated up to 40 Rockwell C. This is why self drilling screws are commonly used in roofing applications in combination with a watertight neoprene sealing washer, and for attaching metal roofing and siding panels to metal stud framing.
Not All TEK Screws are Created Equal
The distinguishing drill point of a Self Driller is what makes them unique, however these points come in different lengths for different applications. The Drill Point of one of these screws is given a TEK number, which can be determined by the length of the flute. TEK points are available in TEK 2, 3 and 4-5. The typical 25 to 16 gauge metal will require the use of a TEK 3, but 14 gauge and below will require TEK 4-5. This is why TEK 5 screws are used for fastening into structural steel. As a general rule of thumb, the higher the TEK number (the longer the drill point), the thicker the metal. It is fundamental that the point is high enough on the TEK scale to pierce the metal being drilled into.
Tapcons are a type of masonry anchor used for light duty fastening to concrete, brick, block and other masonry materials. They are commonly called Concrete Screws or blue screws because of their appearance and how they function. Like all Masonry Anchors, Tapcon Concrete Screws are installed into a hole drilled into the material. They are available in both Slotted Hex Head and Phillips Flat Head varieties. Tapcon Screws work by tapping threads into a pre-existing hole with advanced thread-form technology. The threads of the screw cut into the material surrounding the hole, ensuring a strong and snug fit. The diameter of the pilot hole is determined by the diameter of the screw. It is important that the hole be slightly smaller than the diameter of the screw so that the threads can tap properly. For 3/16″ diameter Tapcon Screws, a 5/32″ drill bit is used for the hole and for 1/4″ Tapcons a 3/16″ masonry drill bit is used. Tapcon Concrete Screws are removable, however it is not recommended to reuse the same hole because the cutting threads can compromise or destroy the holding power.
Tapcons are most commonly seen in the Blue Climaseal™ ceramic coating finish. This blue coating is uniquely applied to the alloy steel fastener in multiple stages through dip-spin technology. The coating provides extended protection against corrosion and rust for the fastener, making the concrete anchors suitable for exterior and long-lasting applications. Check Out Our Selection of Tapcon Concrete Screws Today!
In This Video
Our Fastener Expert shows us how to install concrete screws.
Stainless Steel Grades, Applications and Magnetism
Today, we will look at different grades of stainless steel 18/8, 304, A2, 316, A4 and 410 that are magnetic and non magnetic, or so they say. I am emailed all of the time “Why is this bolt magnetic?” Most common grades of stainless steel are magnetic in some degree. In fact, all of the stainless steel coming into the USA from china and other countries are magnetic in some form. 18/8, 304, A2 and 410 are more magnetic than 316 or A4 stainless steel. The most common grade of stainless steel is 304, or as referred to 18/8, and in metric A2. The second most common grade is 316 which is used in salt water application marine grade, food prep equipment, surgical, medical and pharmaceutical applications. 316 Stainless steel is used in these areas to minimize metallic contamination. 316 stainless is used in marine applications due to its increased resistance to chloride corrosion compared to 304, 18/8, A2 or 410 stainless steel. Also most high-end watches are made with 316 stainless. 410 Stainless steel is used in most construction fasteners when a high strength iron chromium water-resistant product is required, but less corrosion resistant to water.
18/8, 304 and A2 are used in most common construction projects, telecom, car, truck and trailer restoration, playgrounds that are exposed to the elements of natural rain water. These grades are all magnetic. Here is a sample of 304 18/8 Stainless Steel
316 And A4 are used in food prep manufacturing equipment, salt water marine application, surgical and pharmaceutical equipment and products. Watches are made from 316 or A4 stainless steel. Partially magnetic. Here is a sample of 316 Stainless Steel
410 Is used in most construction fasteners in exterior application exposed to the elements. These fasteners are used in standard rain water application where there is no salt water exposure. 410 are magnetic. Here is a sample of 410 Stainless Steel
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