CL04 Clutch Head Countersunk Self Tapping Security Screws
Countersunk head one-way clutch head self-tapping security screws (imperial gauge series), No.6–No.10 as tabulated: head diameters 6.8–9.4 mm, head heights 3.2–4.4 mm. Stainless steel; no lengths published — availability matrix unmarked.
Last updated: 2026-11
Specifications
CL04 is the flush-seating, imperial-gauge member of the clutch head self-tapping line: a countersunk head that disappears into the countersink, a thread that cuts its own path in sheet and plastic, and the same one-way slotted drive — chamfered so a standard screwdriver drives it home and then slips out under any reverse torque. The collected tabulation covers No.6 to No.10 with head diameters from 6.8 mm to 9.4 mm and head heights from 3.2 mm to 4.4 mm; the gauge series is imperial, while the head dimensions are tabulated in millimetres exactly as the collected table prints them. The source states supply in stainless steel, with other materials and sizes available to order. The flush head is the right choice wherever a proud dome would catch fabric, hands or trolleys — public furniture panels, cladding seams, transport interiors — and being a one-way clutch head fixing it is intended for joints that will not be legitimately reopened. The collected availability matrix prints length rows with no legible markings, so lengths are confirmed at quotation.
| Designation | CL04 — countersunk self-tapping security screw, clutch head one-way drive; seats flush in a countersunk hole |
|---|---|
| Gauge range (tabulated) | No.6, No.8, No.10 (imperial gauge series; head dimensions tabulated in mm per the collected table) |
| Head diameter dk per gauge (mm) | No.6 6.8 · No.8 8.1 · No.10 9.4 |
| Head height k per gauge (mm) | No.6 3.2 · No.8 3.8 · No.10 4.4 |
| 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 |
| Materials (collected) | Stainless steel; other materials and sizes to order |
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 (CL04 Clutch Head Countersunk Self Tapping Security 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
Countersunk or round head on a self-tapping one-way screw?
Countersunk — this CL04 — when the surface must stay flush: sliding elements, washdown panels, anywhere a proud head snags or advertises an edge to pry against. Round head — CL03 — when the sheet is too thin to countersink or the substrate cracks under the cone. Both share the one-way clutch drive, so the decision is purely head geometry and sheet thickness, not security level.
The gauges are imperial but the dimensions are millimetres — which do I order in?
Order by the gauge: the collected table organises this SKU as an imperial gauge series (No.6, No.8, No.10) and prints the head dimensions in millimetres as reference values. State the gauge and the length on the RFQ in the units your drawing uses; the quotation confirms the exact thread form and length availability, since the collected matrix marks no cells legibly.
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