Hexagon Head Self Drilling Screw
Specifications: M5.5*19-125
Head: Hexagonal design, allowing direct tightening with an electric spanner or socket; provides high torque and minimises slippage;
Shank: Fully threaded, ensuring a strong clamping force;
Tail: Features an integrated micro twist drill bit, eliminating the need for pre-drilling and completing the three processes—drilling, tapping and tightening—in a single operation;
Product Details
The Hexagon Head Self-Drilling Screw features an integrated drill tip, eliminating the need for pilot holes. It can penetrate colour-coated steel sheets, angle steel and light-gauge steel studs directly, completing drilling, tapping and fastening in a single step. It is widely used in steel-framed industrial buildings, roofing tiles, curtain walls and the joining of sheet metal guardrails.
Two Main Material Types
Galvanised Carbon Steel：Features a thick hot-dip galvanised coating, providing adequate rust protection and offering the best value for money; suitable for standard industrial buildings, colour-coated steel sheds and hoardings;
304/316 Stainless Steel：Offers exceptional corrosion resistance; specifically designed for coastal salt-fog environments, chemical plants and projects with high humidity, ensuring long-term rust-free performance.
Application Advantages
Construction efficiency far surpasses that of ordinary self-tapping screws or bolts, resulting in significant labour savings
Featuring an integrated drill bit and cutting tail, there is no need to pre-drill holes with an electric drill; a single electric impact wrench can complete the three processes of drilling, tapping and tightening in one go. No secondary processing is required for thick steel plates or multi-layer sheet metal overlaps; large-scale roofing projects can save up to half the labour time and reduce drill bit wear costs.
High fastening reliability; resistant to loosening, breakage and slippage
The entire screw undergoes quenching heat treatment, whilst the drill point features high hardness, making it resistant to chipping or snapping when penetrating angle steel or thick colour-coated steel sheets; the full-thread design grips the steel sheet tightly, preventing loosening or thread stripping under vibration or wind loads, ensuring greater long-term stability for steel structures.
The roofing-specific variant features an integrated sealing structure, completely resolving the common issue of water leakage
It is supplied with an EPDM high-weatherability rubber waterproof gasket; once tightened, the gasket is compressed to fit snugly against the roof surface, preventing rainwater penetration and eliminating leaks at the screw holes. This significantly reduces the after-sales costs associated with subsequent repairs for water ingress in industrial buildings, representing an irreplaceable advantage for roofing fasteners.
Multiple material options available, with outdoor corrosion resistance suited to various environments
- Hot-dip galvanised carbon steel version: Excellent value for money, providing protection against wind, rain and rust for open-air workshops and general outdoor applications;
- 304/316 stainless steel version: Resistant to salt spray and corrosion, ensuring long-term rust-free performance in highly corrosive environments such as coastal areas and chemical plants.
Hexagonal head design for effortless installation
The hexagonal head is compatible with sockets and power wrenches, allowing for firm tightening without slipping or rounding off the screw head, and ensuring smoother application of force during work at height or when fastening hard steel materials.
Lower overall cost of ownership
Although the unit price per screw is higher than that of standard self-tapping screws, the elimination of labour costs for drilling, the reduction in rework and repairs, and the lower costs associated with warranty claims for water leaks result in a more cost-effective overall project cost.
Applications
For securing colour-coated steel roofing and wall panels in steel-framed industrial buildings, light-gauge steel studs, solar panel mounting brackets, sheet metal for advertising hoardings, angle steel for guardrails, sheet metal for electrical distribution boxes, pipe reinforcement and more; these are essential fasteners for steel structure projects.
Our Strengths
Sufficient hardness and strong penetration
Made from genuine steel compliant with national standards and subjected to full quenching treatment; the thick steel plates allow drilling without chipping, slipping or snapping, minimising drill bit wear and the need for rework on site;
Effective rust and water resistance
Thickened hot-dip galvanised coating ensures resistance to rust even after prolonged exposure to the elements outdoors; the roofing variant comes standard with an EPDM waterproof gasket, guaranteeing a watertight seal once secured and minimising subsequent after-sales issues;
Comprehensive range and ample stock
We maintain a constant stock of various diameters and lengths, including both stainless steel and carbon steel variants. Whether large or small orders, we can dispatch quickly to ensure your construction schedule remains on track;
Consistent quality control and excellent value for money
Every batch undergoes hardness and drilling tests, with very few defective items; supplied directly from the manufacturer with no mark-ups from middlemen; volume discounts are available for long-term, high-volume orders, and we also support non-standard customisation and private labelling.
Whether you are a construction wholesaler or using the products on your own site, you are welcome to request samples for trial installation – the quality stands up to the rigours of on-site use.