Self Tapping & Self Drilling Screws
What Are Self Tapping Screws?
Self-tapping screws create their own mating threads in a pre-drilled pilot hole. They’re common for thin sheet metal, plastics (with the right point), and general assembly where pilots are easy to produce and head/drive choices need to be flexible.
What Are Self Drilling Screws?
Self-drilling screws include a drill point that makes the pilot and taps in one step. They’re ideal for fastening to steel studs, roofing and metal building panels, or heavier gauges where skipping the pilot saves time.
What Are the Key Differences for Self Tapping & Self Drilling Screws?
- Hole prep — self-tapping needs a pilot; self-drilling makes its own.
- Speed — self-drilling reduces steps in metal; self-tapping can be faster when pilots are batch-drilled.
- Material fit — self-tapping suits thin sheet and plastics; self-drilling suits steel thicknesses matched to the drill-point number.
When Should You Use Self-Tapping & Self-Drilling Screws?
- Choose self-tapping for pre-drilled sheet, plastics, and mixed materials needing broad head/drive options.
- Choose self-drilling to fasten steel without pre-drilling—match the drill-point to total thickness.
What Head & Drive Options Fit Self Tapping & Self Drilling Screws?
- Pan / button / truss — wide bearing for thin sheet.
- Flat — sits flush in a countersink.
- Hex-washer — high-torque drive for framing, roofing, and panels.
- Drives — Phillips, combo, Torx/6-lobe, hex-socket, and security drives.
Materials & Finishes for Self-Tapping & Self-Drilling Screws
- Zinc-plated steel — economical protection for dry interiors.
- 18-8 / 304 stainless — dependable corrosion resistance for most outdoor/indoor use.
- 316 stainless — enhanced resistance for coastal or harsh environments.
- Black phosphate — low-glare indoor finish common on drywall screws.
How Do You Size & Specify Self-Tapping & Self-Drilling Screws?
Order by diameter × thread × length (e.g., #8-18 × 1″, #10-16 × 3/4″, M5-0.8 × 20 mm). Measure length from under the head (flat heads measured overall). For self-drillers, select the drill-point number rated for your material thickness.
Common Applications for Self-Tapping & Self-Drilling Screws
- Sheet-metal fabrication, HVAC, electrical, and appliance assembly
- Metal framing, roofing and wall panels, stitch fastening
- Drywall to wood or metal studs with bugle-head styles
- Public or utility installs using tamper-resistant drives
Installation Tips for Self-Tapping & Self-Drilling Screws
- Self-tapping — drill the recommended pilot and deburr for clean threads.
- Self-drilling — keep the driver square; let the drill point penetrate before applying full torque.
- Sealing — use sealing washers where exterior systems require them.
- Stainless care — consider compatible anti-seize to reduce thread galling.
Self-Tapping & Self-Drilling Screws FAQs
See the accordion below for quick answers on differences, sizing, drill-point selection, materials, and installation best practices.
Note — Guidance here is general. Always follow the product datasheet and job specifications.
If you want any other H2s converted to question-form (e.g., “How Do You Install Self-Tapping & Self-DrillingFasteners that form or cut threads in a pre-drilled pilot hole; common in sheet metal and plastics.
Fasteners with a drill point that creates the pilot and taps in one step; ideal for steel studs and metal panels.
Self-tapping needs a pilot; self-drilling makes its own. Drill-point numbers align with material thickness.
Use self-tapping for pre-drilled sheet or plastics; use self-drilling to fasten steel without a separate pilot.
Pan, button, truss, flat, and hex-washer heads with Phillips, combo, Torx/6-lobe, hex-socket, and security drives.
Order by diameter × thread × length; measure from under the head (flat heads overall). For self-drillers, match the drill-point to material thickness.
Use sealing washers when the roofing or panel system calls for them to prevent leaks.
Use the correct bit, keep it square, apply steady pressure, and consider anti-seize for stainless threads where allowed.