Carbon Steel Flat Head Rivet Nut M3–M12 Countersunk Semi-Hex Blind Rivnut Nutsert

Carbon Steel Flat Head Rivet Nut M3–M12 — Countersunk Semi-Hex Blind Rivnut Nutsert

Carbon steel countersunk flat head blind rivet nuts (rivnuts / nutserts) provide a flush, low-profile threaded insert in thin sheet metal and steel panels from one side only. The countersunk flat head sits completely flush with the panel surface — lower profile than a standard flat head rivnut — making these the correct choice for applications where even a small protrusion would interfere with mating surfaces, gaskets, or sliding components.

Key Specifications

Why Choose Countersunk Flat Head Rivet Nuts?

• Fully flush countersunk head — 90° countersunk head sits completely flush with panel surface; zero protrusion for mating surfaces, gaskets, and sliding components
• Semi-hex body — anti-rotation geometry prevents spinning during bolt installation
• Blind installation — installs from one side only; no rear access required
• Carbon steel (zinc-plated) — economical for indoor and dry environment sheet metal fabrication
• M3–M12 range — covers electronics (M3–M6) through structural sheet metal assembly (M8–M12)

Typical Applications

• Sheet metal enclosure panels where flush surface is required for gasket sealing (M4–M8)
• Sliding door and panel track assembly where protrusions would cause interference (M4–M8)
• Automotive body panel flush threaded insert (M6–M12)
• PC case and server chassis flush threaded insert (M3–M6)
• HVAC ductwork and sheet metal panel flush fastening (M6–M10)
• Industrial machinery steel frame flush threaded insert (M8–M12)

Compatible With

• Standard rivet nut tools with M3–M12 mandrel sets
• 90° countersink drill bit for correct flush seating of countersunk head
• Sheet materials: mild steel, aluminium (min. 0.5mm)
• Mating bolts: ISO 4762 hex socket cap screws, DIN 933 hex bolts M3–M12

Package Contents

• Carbon steel countersunk flat head rivet nuts in selected size and quantity (per variant)
• Note: rivet nut installation tool sold separately

Frequently Asked Questions

Q: What is the difference between a flat head and a countersunk flat head rivet nut?

A: A standard flat head rivet nut has a flat collar that sits on top of the panel surface with a small protrusion. A countersunk flat head rivet nut has a 90° bevelled head that sits in a countersunk hole, resulting in zero protrusion — completely flush with the panel surface.

Q: Do I need to countersink the hole before installing?

A: Yes. Use a 90° countersink drill bit to prepare the hole before installing a countersunk flat head rivet nut. The countersink allows the head to sit flush with the panel surface. Without countersinking, the head will protrude above the surface.

Q: When should I use countersunk vs standard flat head rivet nuts?

A: Use countersunk flat head rivet nuts when the panel surface must be completely flush — for example, where a gasket must seal against the surface, where a mating panel slides over the surface, or where aesthetics require zero protrusion. Use standard flat head rivet nuts for general applications where a small protrusion is acceptable.