Self-Drilling Screws Guide: TEK Screws for Metal Applications

Self-drilling screws, commonly known as TEK screws, feature an integrated drill point that bores through metal before the threads engage. This innovative design eliminates pre-drilling, dramatically reducing installation time and labor costs. The drill point penetrates sheet metal, then the screw threads tap and fasten in one continuous operation. TEK screws are designated by their drill point number (TEK-1 through TEK-5), indicating the maximum metal thickness they can penetrate. Self-drilling screws are essential for metal roofing installation, steel building construction, HVAC ductwork, metal cladding systems, and structural steel framing throughout India. Available at ScrewBazar in multiple head styles (pan, hex, countersunk, truss) and finishes (zinc-plated, galvanized, stainless steel) for every metal fastening application. The drill point design ensures straight, accurate holes without walking or skating across metal surfaces.

PAN SDS (Pan Head Self-Drilling Screws) feature a low-profile wafer head with Phillips drive and an integrated drill point. The pan head provides excellent bearing surface while maintaining a relatively low profile compared to hex head screws. These self-drilling screws are ideal for attaching metal panels, ductwork, and sheet metal assemblies where a lower profile is desired but some head height is acceptable. The Phillips drive allows for easy installation with standard power drivers and hand tools. PAN SDS screws are widely used in HVAC installation, electrical panel assembly, light-gauge metal framing, appliance manufacturing, and metal enclosure assembly. Available with various drill point ratings (typically #2 or #3 point) for different metal thicknesses. Standard sizes range from #6 to #14 with lengths from 13mm to 100mm. Finish options include zinc-plated for indoor use, galvanized for outdoor environments, and stainless steel SS304 for corrosive or marine applications.

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Hex SDS (Hexagon Head Self-Drilling Screws) feature a six-sided hex head with built-in sealing washer (EPDM or neoprene) and a self-drilling point. These are the most popular screws for metal roofing and wall cladding applications across India. The hex head allows high torque application using socket drivers, while the bonded washer creates a weather-tight seal. Hex SDS screws are essential for corrugated metal roofing, standing seam metal roofs, metal wall cladding, purlin attachment, and gutter installation. The integrated EPDM washer compresses to form a watertight seal, crucial for preventing leaks in roofing applications. Available in various colors to match roofing panels (red oxide, blue, green, gray, white, and galvanized finish). Material options include carbon steel with zinc coating, 410 stainless steel, and marine-grade 316 stainless steel.

CSK SDS (Countersunk Self-Drilling Screws) combine a flat, countersunk head with a self-drilling point for flush-mounted metal fastening. The flat head sits below the material surface, creating a smooth, streamlined finish without protruding heads. These screws are essential where a completely flush surface is required for aesthetic or functional reasons. Common applications include metal door frames, automotive body panels, aluminum curtain wall systems, decorative metal panels, machinery covers, and metal furniture. The countersunk design is particularly valuable where protruding screw heads would interfere with moving parts, catch on clothing, or detract from appearance. Available in various countersunk angles (82° or 90°) to suit different material profiles. Finish options include zinc-plated, black oxide, and stainless steel SS304 or SS316.

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Truss Phillips SDS screws feature an extra-wide, low-profile truss head (also called modified truss or wafer head) with Phillips drive and self-drilling point. The oversized head provides maximum bearing surface, making these screws ideal for thin metals, soft materials, and applications prone to vibration. The wide head distributes clamping force over a larger area, preventing pull-through and material distortion. Truss Phillips SDS screws are commonly used in thin sheet metal assembly, aluminum panel installation, HVAC ductwork, light-gauge steel framing, trailer construction, and sign panel mounting. The low-profile truss head minimizes snag hazards while providing superior holding power compared to standard pan head screws. These screws are particularly effective in applications where materials expand and contract due to temperature changes, as the wide head accommodates slight material movement. Available with #2 or #3 drill points for different metal thicknesses. Standard sizes include #8, #10, and #12 with lengths from 16mm to 50mm. Supplied in zinc-plated steel, stainless steel SS304, and aluminum-compatible coatings. The Phillips drive enables fast installation while the drill point eliminates pre-drilling. Get competitive pricing on Truss Phillips SDS screws with bulk orders and technical support from our fastener specialists.

Selecting the correct self-drilling screw requires consideration of several factors: metal thickness determines drill point rating needed (#2 point for up to 0.9mm, #3 point for 0.9-3mm, #4 point for 3-6mm, #5 point for 6-12mm); application type influences head style (hex with washer for roofing, pan for general assembly, CSK for flush mounting, truss for thin materials); environmental conditions dictate finish (zinc-plated for indoor, galvanized for outdoor, stainless steel for marine or chemical exposure); and fastening configuration affects length selection (screw should penetrate backing material by at least 3 threads for wood, 1.5x material thickness for metal-to-metal). Always verify drill point rating matches your materials to ensure proper drilling and thread formation. Use proper installation torque to compress sealing washers without over-tightening.

Self-drilling screws are indispensable in modern construction and manufacturing: metal roofing contractors use millions of Hex SDS screws annually for roof and wall cladding; steel building fabricators rely on PAN SDS and Hex SDS for purlin and girt attachment; HVAC installers use PAN SDS for ductwork assembly; automotive manufacturers use CSK SDS for body panel attachment; trailer manufacturers depend on Truss Phillips SDS for flooring and siding; and electrical contractors use various SDS types for metal panel and enclosure assembly. We supply self-drilling screws to contractors, manufacturers, and OEMs across Bangalore, Mumbai, Delhi NCR, Chennai, Hyderabad, Pune, Ahmedabad, and 500+ cities throughout India. Same-day dispatch available for stock items with bulk discounts for high-volume orders.