Flat Head Self Sealing Screws M3 M4 M5 Zinc Plated Black Oxide With Silicone O Ring For Instrument Panel Assembly
What is a flat head sealing screw anyway?
It is a countersunk screw with a rubber ring tucked under the head. Drive it in and the head ends up flush with the surface. Meanwhile, the rubber ring gets squished and seals the hole. Water and dust? They stay out.
Why pick flat head over other types?
Two reasons. First, looks. The head disappears into the material. No bumps sticking up. No edges to snag on things. Second, space. Flush mounting means nothing protrudes, so covers and wires slide right over.
How the seal actually works
The rubber ring sits in a groove cut into the underside of the head. As you tighten the screw, that ring gets pressed between the head and the surface. The more you turn, the tighter it seals. When fully seated, the rubber has filled the gap completely. Water cannot get past.
O ring materials we use
Metal options
Sizes we carry
M2, M2.5, M3, M4, M5, and M6. Lengths from 4mm to 30mm. Custom sizes available if you need them.
Where these get used
PCB mounting. Instrument panels. Electronics enclosures. Marine gear. Control boxes. Anywhere you need a flush finish and a watertight seal.
Quality
We check every O ring before it goes out. Every batch is tested. ISO 9001 and ISO 10012 certified.
FAQ
Yes. It is countersunk. Sits level with the surface.
Yes. The hole has to be countersunk for the head to sit flush.
No. The O ring handles the sealing. No sealant required.
304 stainless works. 316 stainless is better near saltwater.
One meter of water for thirty minutes. No leaks.
Yes. The rubber springs back. Reuse them a few times.
Yes. Send us your drawing or sample.
- Flat head sits flush with the surface
- Rubber O ring under the head seals the hole
- No sealant needed
- IP67 and IP68 waterproof ratings
- NBR, silicone, EPDM, or FKM rubber
- 304 stainless, 316 stainless, or zinc plated
- M2 to M6 sizes
YH Fastener has been making screws and fasteners since 1998. We are based in Guangdong, China. Our product range includes flat head sealing screws, self tapping screws, machine screws, shoulder screws, and custom fasteners. We hold ISO 9001 and ISO 10012 certifications. Every batch is inspected before it leaves our factory. We sell direct and ship to over 60 countries worldwide. Got a custom requirement? Send us your drawing or sample. We are happy to make what you need.
