Self-drilling screws combine drilling and fastening in a single operation. Their drill-point tip creates the required hole as the screw is installed, eliminating the need for a separate pre-drilling step in suitable metal applications.
WEIFENG supplies self-drilling screws in multiple head styles, drive types, materials, finishes and drill-point configurations for sheet metal, roofing, steel structures, decking and façade applications. Options include hex washer head, pan head and countersunk designs, as well as DIN 7504 self-drilling screws and versions with EPDM sealing washers.
When selecting a self-drilling screw, consider the material being fastened, total metal thickness, drill-point length, head style, drive type and installation requirements.
How to Choose the Right Self-Drilling Screw?
The correct screw should match both the material being joined and the installation conditions.
| Selection Factor | Options / What to Consider |
|---|
| Head Type | Hex Washer, Pan, Countersunk, Large Washer |
| Drive Type | External Hex, Phillips, Torx |
| Drill Point | Tek 1 to Tek 5 |
| Material Thickness | Match the drill point to the total steel thickness |
| Screw Material | Carbon Steel or Stainless Steel |
| Surface / Sealing | Zinc-plated, plain or sealing washer options depending on product |
| Applications | Roofing, sheet metal, steel structures, decking and façades |
For metal fastening, the drill point must be long enough to fully penetrate the combined material thickness before the threads begin engaging the workpiece.
Self-Drilling Screw Head Types and Drive Options
Different head and drive configurations affect installation speed, torque transfer, surface finish and load distribution.
| Head Type | Typical Drive | Typical Driver | Common Applications |
| Hex Washer Head | External Hex | Socket | Roofing, steel structures and applications requiring higher installation torque |
| Pan Head | Phillips | PH2 | Sheet metal, enclosures and general metal fastening |
| Countersunk Head | Phillips | PH2 | Applications requiring a flush finished surface |
| Large Washer Head | Phillips / Torx | PH2 / T20–T25 | Thin sheet and façade applications requiring a larger bearing surface |
| Torx Head | Torx | T20 / T25 / T30 | Higher-torque fastening where reduced cam-out is preferred |
For many ST3.5–ST4.8 Phillips self-drilling screws, PH2 is commonly used, while larger sizes may require a larger driver. Always confirm the actual drive size of the selected screw before installation.
Tek Drill Point Selection Guide
The drill point determines how much metal the screw can penetrate. Based on the supplied selection reference, the following ranges can be used as a preliminary guide:
| Drill Point | Reference Total Steel Thickness | Typical Screw Sizes |
| Tek 1 | Up to 1.5 mm | ST3.5, ST3.9 |
| Tek 2 | Up to 2.5 mm | ST4.2, ST4.8 |
| Tek 3 | Up to 4.0 mm | ST4.8, ST5.5 |
| Tek 4 | Up to 6.0 mm | ST5.5, ST6.3 |
| Tek 5 | Up to 12 mm | ST6.3 large drill-point screws |
Important: The drill-point section should extend beyond the total thickness of the materials being drilled. The point should penetrate the steel before the screw threads engage; otherwise drilling performance may decrease and the drill point or screw may be damaged.
Exact drilling capacity should always be confirmed against the specification of the individual screw being purchased.
Self-Drilling Screws by Application
Roofing and Cladding
Hex washer head self-drilling screws are commonly selected for metal roofing and cladding because the external hex drive supports efficient installation. Versions fitted with bonded EPDM washers can provide a sealing interface around the fastening point where the product specification calls for it.
For roofing applications, consider:
Total sheet and supporting steel thickness
Required drill-point length
Screw diameter and length
Head and socket size
Washer and sealing requirements
Environmental and corrosion conditions
Sheet Metal
Pan head and countersunk self-drilling screws are suitable for many sheet-metal fastening applications.
Choose a pan head when a conventional bearing surface is acceptable. Choose a countersunk head when the screw head needs to sit flush with the installed surface.
Decking and Façade Systems
Self-drilling screws used for decking and façade installation should be selected according to substrate thickness, head configuration, surface requirements and environmental exposure.
A larger bearing head can be useful where load needs to be distributed over thinner sheet material, while higher-torque drive systems can improve installation control in demanding applications.
Self-Drilling vs Self-Tapping Screws
Although the terms are sometimes confused, the two screw types perform different functions.
| Feature | Self-Drilling Screw | Self-Tapping Screw |
| Drill-Type Point | Yes | Not necessarily |
| Creates Its Own Hole | Yes, in suitable material | Not always |
| Creates Its Own Thread | Yes | Yes |
| Pilot Hole | Generally not required for suitable applications | May be required depending on screw and material |
| Typical Use | Metal drilling and fastening in one operation | Thread forming/cutting in a prepared or suitable substrate |
If the application requires drilling through metal and fastening in one operation, a self-drilling screw is generally the more appropriate starting point. If a hole already exists or the screw is designed primarily to form threads, consider a self-tapping screw.
Installation Tips for Self-Drilling Screws
Correct installation helps improve drilling performance and reduces damage to the screw or driver.
Match the driver bit or socket exactly to the screw drive.
Keep the screw perpendicular to the workpiece during drilling.
Select the drill point according to the total metal thickness.
Avoid using a worn driver bit that can damage the screw recess.
Use higher speed for thinner metal and reduce speed when drilling thicker steel.
Avoid excessive pressure; allow the drill point to cut through the metal.
Confirm installation recommendations when fastening stainless steel or demanding substrates.
As a reference, the supplied technical guidance recommends approximately 1500–2000 rpm for thinner sheet and 500–800 rpm for thicker steel, but actual settings should be adjusted according to screw specification, material, tool and installation conditions.
Common Self-Drilling Screw Problems
The Screw Will Not Drill Through the Steel
The selected drill point may be too short or rated for material thinner than the actual steel thickness.
For example, using a smaller drill-point configuration on substantially thicker steel can wear the drill point before penetration is complete.
The Screw Recess Is Stripping
Check whether the driver type and size match the screw. A worn driver can also damage the recess and reduce torque transfer.
The Drill Point Breaks
Keep the screw perpendicular to the workpiece. Installing at an angle increases uneven loading on the drill point and can lead to damage.
The Screw Spins Without Fastening
Confirm that the drill point has fully penetrated the steel before the threads begin engaging and that the screw diameter and thread configuration are suitable for the application.
Why Choose WEIFENG Self-Drilling Screws?
WEIFENG offers self-drilling screw solutions for different metal fastening requirements, including:
Multiple head and drive configurations
DIN 7504 self-drilling screw options
Carbon steel and stainless steel products
Roofing screws with sealing washer options
Screws for sheet metal, decking and façade applications
Different sizes, finishes and configurations
OEM and customized fastening solutions
For project purchasing, send us your screw size, material, finish, head type, drive type, application and total metal thickness. Our team can help identify a suitable self-drilling screw configuration.
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