Self-Drilling Screw
Screws · TEK screw · drill-point screw
Definition: A self-drilling screw has a drill-shaped point that bores its own hole through metal, then taps its own thread — no pre-drilling required.
Anatomy
■ Head■ Shank■ Threads■ Point
Governing standards: SAE J78 · ASME B18.6.4
Common Sizes
| Inch | Metric | Head width | Head height |
|---|---|---|---|
| #8 x 1/2 | M4.2 x 13 | 5/16 | 1/8 |
| #10 x 3/4 | M4.8 x 19 | 3/8 | 5/32 |
| #12 x 1 | M5.5 x 25 | 7/16 | 5/32 |
Representative sizes. Full dimensional data lives in the standards listed below.
Grades & Strength
| Grade | Material | Tensile (psi) | Marking |
|---|---|---|---|
| Standard | case-hardened steel | — | None |
| Stainless (limited drilling) | 410 stainless, hardened | — | None |
Materials
- Zinc-plated case-hardened steel
- Coated (for roofing)
- 410 stainless (thin gauge only)
Pros & Cons
Pros
- One-step drill-and-fasten — huge time saver
- No pilot hole or tap needed
- Fast with a driver or impact gun
Cons
- Limited to the material thickness the drill point can handle
- Drill point can walk or snap on hard steel
- Stainless versions drill poorly — pick the right grade
Typical Uses
- Steel stud framing
- Metal roofing and siding
- Sheet metal to structural steel
- HVAC ductwork
Alternatives & Related
- Self-Tapping Screw — For pre-drilled holes where you only need thread-cutting
- Machine Screw — Where a tapped hole already exists
Where to Buy
Affiliate links — we may earn a commission at no cost to you.
FAQ
What does a self-drilling screw do?
It drills its own hole and forms its own thread in one operation, typically into sheet metal or thin structural steel.
Self-drilling vs self-tapping?
A self-drilling screw makes its own hole (drill point). A self-tapping screw only cuts threads and needs a pre-drilled or pre-punched hole.