CL05 Clutch Head Round Security Self Drilling Screws
Round head one-way clutch head self-drilling security screw, No.10 as the single tabulated gauge: head diameter 8.9 mm, head height 1.75 mm. Drill-bit point eliminates the separate pilot hole; stainless steel; length availability unmarked in the collected matrix.
Last updated: 2026-11
Specifications
CL05 folds the clutch head one-way principle into a self-drilling screw: the drill-bit point pierces the steel, the thread forms as it drives, and the slotted chamfered head locks out reverse torque — one operation from bare steel to a permanent, tamper-resistant fixing with nothing more exotic than a flat-blade screwdriver. The collected tabulation covers a single gauge, No.10, with an 8.9 mm head diameter and 1.75 mm head height, and states supply in stainless steel; the collected source also notes dedicated removal tools exist for clutch head fixings but are recommended only for stainless versions, which matches the material this SKU is stated in. The drill point is the operational difference from CL03: no separate drilling station, no drift between pilot hole and screw — the reason self-drillers dominate ducting, cladding rails and enclosure assembly. The collected availability matrix prints a length row with no legible marking, so no length is claimed here and availability is confirmed at quotation.
| Designation | CL05 — round head self-drilling security screw, clutch head one-way drive; drill-bit point, no separate pilot hole |
|---|---|
| Gauge range (tabulated) | No.10 (single gauge; the source tabulates No.10 at 4.8 mm nominal) |
| Head diameter dk (mm) | No.10 8.9 |
| Head height m (mm) | No.10 1.75 |
| Length availability | No legible markings in the collected availability matrix — confirmed at quotation |
| Security principle | One-way permanent fixing — standard slotted screwdriver installs; anti-clockwise torque slips out; special removal tooling exists but is recommended only for stainless clutch head screws |
| Materials (collected) | Stainless steel |
| Thread gauge | Head diameter dk (mm) | Head height m (mm) |
|---|---|---|
| No.10 | 8.9 | 1.75 |
Materials
- Stainless steel
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (CL05 Clutch Head Round Security Self Drilling Screws) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
Self-tapping or self-drilling — CL03 or CL05?
It is the pilot hole that decides. CL03 needs a pre-drilled pilot and suits plastics, thin sheet and pre-punched holes; CL05 carries its own drill point and goes through steel sheet in one pass, which is why it is the faster choice on ducting, framing and enclosure runs. Both are one-way clutch head fixings in stainless, so security behaviour and corrosion resistance are the same — choose by substrate and installation speed.
Can a one-way clutch head screw ever be removed?
Only with dedicated removal tooling — the collected source states special removal tools exist for clutch head fixings and are recommended for the stainless versions, which is what this SKU is supplied in. That is the design intent: irreversible to ordinary tools on site, recoverable by a workshop that deliberately stocks the tool. If a joint needs scheduled reopening with common tools, a two-way drive such as pin-TX is the better match.
What is the MOQ and lead time for these security screws?
Minimum order quantity is 10,000 pieces per item. Stocked sizes ship in 3–7 days; sizes quoted as available to order, and non-standard sizes or materials, are quoted with a confirmed schedule. Confirm the exact schedule against quantity and size mix at quotation.
What should an RFQ for these security screws state?
State the designation code (CL01 through CL06) and head style, the drive (clutch head one-way — fitted with a standard slotted screwdriver), nominal thread size and length, material and finish, the substrate or mating part, required certificates, and quantity per size — plus destination country.
Related knowledge
- Thread-Forming vs Thread-Cutting vs Thread-Rolling Self-Tapping Screws: What the Evidence Settles on Base Material
- Screw Family Selection by Base Material: Wood, Machine and Self-Tapping Threads, Engagement and Coating
- Hex Bolts vs Socket Head Cap Screws: What the Evidence Settles on Strength, Clearance and Cost
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support