💧 Screw Waterproof Caps – Plastic Cap for 5.2mm Hex Head Self‑Drilling Screws & Bolts
Keep your outdoor fasteners dry and rust‑free. These small plastic caps snap directly onto 5.2mm hex head self‑drilling screws, lag bolts, or any fastener with a 5.2mm across‑flats hex head. The snug fit seals out rain, snow, and dust, preventing corrosion and giving your project a clean, finished look. Perfect for metal roofing, fence installations, decking, or any exterior screw that needs extra protection. Made from UV‑resistant plastic and rated for metric measurements, these caps stay flexible in cold weather and won’t crack under summer heat. No tools required – just press on by hand.
🔧 Why You Need These Screw Waterproof Caps
Designed for 5.2mm hex heads – Fits self‑drilling screws and bolts with a standard 5.2mm hex drive (common in roofing and sheet metal screws). Snaps on securely without adhesive.
Waterproof & weather‑resistant – Creates a moisture barrier over the screw head, preventing water from seeping into the threads and reducing rust.
Durable plastic construction – UV‑stabilized material resists cracking, fading, and warping from sunlight and temperature changes.
Easy hand installation – No special tools needed. Just align and push onto the hex head until it clicks or seats flush.
Metric system compatibility – Engineered for metric‑sized hex heads (5.2mm across flats). Works with many European and Asian self‑drilling screw brands.
Multi‑purpose use – Ideal for metal roofing, gutter guards, electrical box covers, outdoor furniture, sign mounting, and RV accessories.
💡 Pro tip: Apply a small dab of silicone sealant inside the cap for maximum waterproofing in extreme weather (e.g., coastal or heavy rain zones).
💬 Frequently Asked Questions – 5.2mm Screw Waterproof Caps
Will these caps fit any 5.2mm hex head screw, even if it’s not a self‑drilling type?
Yes – as long as the screw or bolt has a standard 5.2mm hex head (across flats), the cap will fit. This includes self‑drilling screws, standard hex head bolts, and some hex washer head screws. For best results, measure your hex head’s width before ordering.
Are these caps truly waterproof, or just dust covers?
They provide a very good water seal for rain, splashing, and hose spray. The cap snaps tightly around the hex head, creating a physical barrier. However, they are not designed for submerged applications (e.g., underwater bolting). For maximum waterproofing in driving rain, adding a dab of silicone inside the cap is recommended.
What temperature range can these plastic caps handle?
They are rated from approx. -20°C to +80°C (-4°F to 176°F). The plastic remains flexible in cold weather (won’t become brittle) and resists softening in normal summer heat. For extreme high‑temp environments (like engine compartments), consider silicone caps instead.
Can I reuse a cap after removing it?
Yes, usually. The snap fit may loosen slightly after repeated removals, but for occasional access (like seasonal maintenance), they can be reused several times. For permanent sealing, it’s best to use new caps after removal.
Do you offer these caps in colors other than black/gray?
Most stock is black or gray to blend with roofing and hardware. For large orders, we can supply white, brown, or custom colors. Please contact us with your requirements.
Will these caps fit a 5.5mm hex head? The screw I have is slightly larger.
No – these are precisely molded for 5.2mm across flats. A 5.5mm hex head will be too large and may split the cap. Please measure carefully. If you have 5.5mm heads, look for our “5.5mm hex cap” model (sold separately).