Self Drilling Screws
Self drilling screws combine a drilling point and a tapping thread in one fastener, allowing them to penetrate metal sheets and form mating threads without a separate drilling operation. The drill point design, thread geometry and screw dimensions all influence drilling performance and fastening strength. Different head styles serve different installation requirements, from hex washer heads for applications requiring a larger bearing surface to pan heads and countersunk heads for different assembly designs. We supply metric self drilling screws in sizes from ST2.9 to ST6.3 and inch series sizes from #4 to 1/4”, with a range of dimensions and configurations for metal-to-metal fastening and sheet metal assembly.
Producing reliable self drilling screws requires careful control of forming, thread rolling and heat treatment. We use dedicated cold heading and thread rolling machines to produce consistent head shapes, thread profiles and dimensional accuracy. Carburizing and hardening processes are controlled to achieve the surface hardness needed for drilling while maintaining suitable core properties to resist torsional loads during installation. Surface treatments are also managed according to the specified finish and application requirements. Depending on the product type, mechanical and functional performance can be evaluated against applicable requirements, including ISO 10666 and SAE J78, with attention to drilling capability, torsional strength and consistency between production batches.
Specification:
| Item | Metric Self Drilling Screws | Imperial Self Drilling Screws |
|---|---|---|
| Size Range | ST2.9-6.3 | #4-1/4" |
| Thread Standard | ISO 1478 | SAE J78 |
| Material | Cabon Steel,Stainless Steel | Cabon Steel,Stainless Steel |
| Mechanical Property | ISO 10666 | SAE J78 |
| Surface Treatment | Black Oxidation, Zinc Plated, Bright Finish,Passivation | Black Oxidation, Zinc Plated, Bright Finish,Passivation |
| Inspection | Dimension,Thread,Mechanical Proeprty,Coating | Dimension,Thread,Mechanical Proeprty,Coating |
Dimension Standard:
The dimensions of hexagon socket countersunk head cap screws are specified according to the applicable metric or inch standard. For metric sizes, DIN 7991 and ISO 10642 define the principal dimensions, including thread diameter, length, head diameter, head height and hexagon socket dimensions. For inch-series screws, ASME B18.3 specifies the corresponding dimensional requirements for socket countersunk head screws.
Mechanical Proeprty:
ISO 10666 – Mechanical and Functional Requirements
ISO 10666 specifies mechanical and functional requirements for steel tapping screws. Relevant performance characteristics include hardness, torsional strength and other applicable test requirements. These properties help assess the screw’s resistance to breakage during installation and its ability to form threads in the mating material. Applicability depends on the screw design and the requirements of the specified standard.
SAE J78 – Steel Self-Drilling Tapping Screws
SAE J78 covers steel self-drilling tapping screws, including relevant product requirements and performance testing. In addition to torsional strength, the drilling performance of the screw is important for ensuring that the drill point penetrates the intended material under specified test conditions. Drill point geometry, heat treatment and material properties all contribute to reliable drilling and fastening performance.