Self-drilling metal screws Celo 4.2×13 mm zinc-coated CNBOP pack of 500

Pack of 500 Celo self-drilling metal screws, size 4.2×13 mm, zinc-coated and marked CNBOP. These fasteners combine a self-drilling tip with a threaded shank to allow direct installation into thin steel sheets, light metal profiles and similar substrates without prior hole preparation. The zinc coating provides basic corrosion resistance suitable for many indoor and covered outdoor applications. The screw geometry and drive are intended for quick, repetitive fastening work used in construction, roofing, ventilation and metal fabrication.

Advantages

Self-drilling tip eliminates the need for separate drilling, reducing installation time and tool changes. The compact 4.2×13 mm dimensions are suited to fastening thin-gauge metal without excessive protrusion. Zinc coating offers a protective layer against corrosion in non-demanding environments. Pack quantity of 500 supports larger projects or repeated small jobs, lowering the need for frequent reordering.

Suitable for

• Fastening thin steel sheets and metal roofing panels
• Attaching light-gauge metal profiles and trims
• HVAC ductwork assembly and mounting brackets
• General metalworking tasks where self-drilling screws are required

When it may not be suitable

These screws are designed for thin metal and light structural attachments; they are not intended for heavy structural loads or thick steel where higher-strength or larger fasteners are required. The zinc coating provides moderate corrosion protection but is not suitable for prolonged exposure to highly corrosive environments such as marine or chemically aggressive conditions.

Key specifications

• Size: 4.2 × 13 mm (diameter × length)
• Head and drive: screwdriver-compatible head for rapid installation
• Tip type: integrated self-drilling tip for metal
• Coating: zinc-coated for basic corrosion resistance
• Quantity: 500 pieces per pack

How to use

Select an appropriate screwdriver or powered driver with the correct bit for the screw head. Position the screw perpendicular to the sheet or profile to ensure a clean drill and thread engagement. Apply steady pressure and moderate speed to allow the self-drilling tip to penetrate the metal; avoid excessive torque once full penetration is achieved to prevent stripping the head or damaging the threads. For best results, ensure the mating substrate thickness is within the recommended range for a 4.2×13 mm self-drilling screw.

What to consider before purchase

• Confirm substrate thickness and material to ensure the 13 mm screw length provides adequate engagement.
• Verify driver compatibility with the screw head to prevent cam-out or damage.
• Assess environmental exposure—choose a different coating or material for highly corrosive or external coastal use.

Usage recommendations

Use a controlled-speed driver and appropriate bit, start perpendicular to the surface, and avoid over-torquing. Store the screws in a dry place to maintain the zinc coating’s effectiveness.