Flat Head Ribbed Rivet Nuts

What are flat head ribbed rivet nuts? These combine a ribbed body that bites into the hole wall with a low profile flat head that spreads clamping load across the panel. The pairing covers the two things most likely to go wrong with a rivet nut in sheet metal: the insert spinning under torque, which the ribs prevent, and the head pulling through thin material under load, which the wide bearing face resists. AlbanyCountyFasteners.com stocks these in thinwall construction, in 18-8 stainless and aluminum, in inch and metric threads.

Flat Head

Why thinwall and ribbed work well together

Thinwall bodies collapse more readily than thickwall, which is exactly what you want in light sheet metal where a stiffer insert might not form a proper bulge behind the panel. But that easier collapse also means less radial pressure against the hole wall, so a smooth thinwall insert has relatively little holding it against rotation. Ribs restore what thinwall gives up: instead of depending on how hard the body presses outward, the serrations cut into the hole wall and key the insert mechanically. The result is an insert that sets reliably in thin material and still resists a firmly torqued bolt, which is the combination most sheet metal work actually needs.

Why choose flat head ribbed rivet nuts

Ribbed body resists spinning under torque in thin and soft panel
Wide flat head spreads load and prevents pull-through
Low profile head keeps the installed height down
Thinwall construction sets reliably in light sheet metal
Available in stainless and aluminum, inch and metric

Materials available

18-8 stainless in inch threads from #10-32 through 3/8-16
18-8 stainless in metric M6 and M8
Aluminum in inch threads from #10-32 through 3/8-16
Aluminum in metric M5, M6, and M8

Common applications

Sheet metal enclosures, panels, and equipment housings
Automotive and truck accessory mounting
Chassis and tube frames in thin wall section
Trailer and RV fixture attachment
Machinery guards and access covers
Marine and outdoor equipment in stainless

Where clearance is tight and a smaller head is needed, see the reduced head low profile range. For the strongest anti-rotation available, half hex rivet nuts key into a hex hole.

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Flat Head Ribbed Rivet Nut FAQs

How low is a low profile flat head?

Lower than a standard flat head while keeping the same wide bearing diameter. It still sits proud of the panel, just by less. For a genuinely minimal profile, a reduced head insert is smaller in both height and diameter.

Is thinwall strong enough?

For sheet metal panel work, yes. Thinwall is designed around light material, where its easier collapse forms a better bulge than a stiff thickwall body would. For heavier panel and higher load, thickwall carries more.

Do metric and inch inserts use the same tool?

The mandrel must match the thread, so M6 and 1/4-20 need different mandrels even though the sizes are close. Kits usually include several mandrels to cover a working range.

What grip range do these cover?

It varies by size, typically from around 0.020 up to 0.165 inch on inch sizes. Check the specific insert, and measure your panel before ordering rather than estimating.

Can I use stainless inserts in an aluminum panel?

Only in dry conditions. Stainless against aluminum with moisture present corrodes the aluminum around every hole. For aluminum panels outdoors or in marine service, use aluminum inserts.

What happens if the hole is slightly oversize?

The ribs have less material to bite into and spin resistance drops. Ribbed bodies tolerate slight variation better than smooth ones, but drilling to specification remains the single most important step in the installation.