18-8 Stainless Steel Thinwall Ribbed Low Profile Head Rivet Nuts

Why stainless is worth it for a rivet nut

Because of where a rivet nut sits. The insert is set through a panel and clamped tight against it, which means the head bears directly on the panel surface and the body fills the hole completely. There is nowhere for moisture to drain and no way to inspect the joint once installed. A plated steel insert corrodes at the head first, where the plating is thinnest from forming, and the rust then works down into the hole. Because the insert cannot be removed without drilling, that corrosion is not something you fix later. Stainless removes the problem, which matters most on trailers seeing road salt, boats, and anything that gets washed down.

Why choose 18-8 stainless ribbed rivet nuts

• Substantially higher load capacity than aluminum inserts of the same thread
• Corrosion resistance in marine, washdown, and road salt environments
• Ribs bite the hole wall to resist spinning under torque
• Thinwall body sets reliably in light sheet metal
• Low profile flat head spreads load without excessive height
• Correct galvanic match for steel and stainless panels

Inch sizes and grip ranges

• #10-32, 0.475 inch length, 0.020 to 0.130 inch grip
• 1/4-20, 0.580 inch length, 0.027 to 0.165 inch grip
• 5/16-18, 0.690 inch length, 0.027 to 0.150 inch grip
• 3/8-16, 0.690 inch length, 0.027 to 0.150 inch grip
• Measure total panel thickness against the grip range before ordering

Common applications

• Marine hardware, boat fittings, and dock equipment
• Trailer frames and panels exposed to road salt
• Food processing and washdown equipment
• Outdoor machinery and agricultural equipment
• Steel chassis and tube frames carrying real load
• Any joint where the insert must not corrode after installation

For metric threads in the same specification, see our metric stainless ribbed rivet nuts. On aluminum panels, aluminum inserts avoid a galvanic couple.

Related Categories

• Flat Head Ribbed Rivet Nuts
• Aluminum Ribbed Rivet Nuts
• Reduced Head Ribbed Rivet Nuts
• Rivet Nuts
• Rivet Tools

18-8 Stainless Ribbed Rivet Nut FAQs

Are stainless rivet nuts harder to set?

Yes, noticeably. Stainless requires more pulling force than aluminum, and 5/16-18 and 3/8-16 in particular take real effort with a basic hand tool. A ratcheting or pneudraulic rivet nut tool is worth having for these sizes.

Can I use these in an aluminum panel?

In dry indoor conditions yes, but not where moisture is present. Stainless is more noble than aluminum, so the panel corrodes preferentially around each hole until the insert works loose. Use aluminum inserts for aluminum panels outdoors.

Is 18-8 the same as 304?

Effectively yes for this purpose. 18-8 describes the 18 percent chromium, 8 percent nickel composition shared by the 300 series austenitic grades, and 304 is the most common of them. Both give the corrosion resistance these inserts are chosen for.

How much load will these hold?

Considerably more than aluminum at the same thread size, though the panel usually sets the limit rather than the insert. A stainless insert in thin sheet will pull through the panel before the insert itself fails.

Are they magnetic?

They may show slight magnetic response. The cold forming that shapes the insert body induces some magnetism in austenitic stainless. That is normal and does not indicate the wrong material.

What hole size do I drill?

The diameter specified for the insert, held reasonably closely. Oversize holes are the main cause of spin-out. Ribbed bodies tolerate slight variation better than smooth ones, but drilling to specification is still the most important step.