Item # RNN031C1SS
5/16-18 UNC FLANGE KNURLED BODY RIVETNUT, 0.027-0.150" GRIP, 18-8 STAINLESS STEEL
Item # RNN031C1SS
5/16-18 UNC FLANGE KNURLED BODY RIVETNUT, 0.027-0.150" GRIP, 18-8 STAINLESS STEEL
- UM: EA
- Brand: RIVETKING
The RNN031C1SS is a 5/16-18 18-8 stainless steel flange-style knurled body rivet nut from the RivetKing IKF (low profile head) thinwall series. Designed for blind installation in sheet metal and panel applications where threads are needed but back-side access is impractical, this rivet nut installs from one side of the workpiece and provides a permanent threaded socket once set.
Typical applications: Heavy use in automotive accessories, off-road vehicle modifications, equipment manufacturing, panel mounting, and general industrial fabrication where moderate load capacity is needed. The 18-8 stainless steel material is well-suited to marine, food processing, outdoor exposure, medical equipment, chemical processing, corrosion-prone environments.
Specifications
| Property | Value |
|---|---|
| Thread Size | 5/16-18 UNC |
| Material / Finish | 18-8 Stainless Steel |
| Series | IKF (RivetKing thinwall, low-profile head, knurled body) |
| Grip Range | 0.027-0.150" |
| Recommended Drill / Hole Size | 0.531" |
| Head Diameter | 0.685" |
| Body Diameter | 0.530" |
| Length (open end) | 0.690" |
| RivetKing Part # | 31C1IKF3P |
Installation: Drill a 0.531" hole in the workpiece. Insert the RNN031C1SS from the accessible side and set with a rivet nut tool — the body collapses against the back side of the panel and the knurled flange grips the front side to prevent rotation under torque. Recommended grip range is 0.027-0.150" (sheet thickness).
For step-by-step instructions: see our How to Install Rivet Nuts guide for the complete process, common mistakes, and verification tips.
Tool selection: Use a pneumatic or hydraulic rivet nut tool for production volume. A battery-powered cordless tool also works well at this size. Hand tools are workable for occasional installs but become fatiguing in volume. Both spin-spin and spin-pull tool types are compatible with the IKF series.
Technical Notes
| Property | Value |
|---|---|
| Recommended Bolt Torque | 156 in-lbs (per RivetKing Rev. B test data) for steel bolts. Stainless thread engagement may require slightly lower values to prevent galling. |
| Static Pull-Out Strength | 1,370 lbf in 0.062″ steel sheet |
| Push-Out Strength | 3,020 lbf in 0.125″ steel sheet |
| Spin-Out Resistance (anti-rotation) | 80 in-lbs in steel |
| Note for stainless variant | Performance values shown are for steel zinc baseline. Stainless 18-8 typically delivers comparable pull-out with slightly lower torque-out resistance; use anti-seize on bolt threads to prevent galling. |
| Hole Tolerance | +0.006″ / -0.000″ (per RivetKing 2025 catalog) |
| Material Certification | 18-8 Stainless Steel (300 Series) |
| Installation Tool Compatibility | Compatible with spin-pull or spin-spin rivet nut installation tools. Knurled body collapses against panel back-side during setting. |
| Installation Reference | See our step-by-step installation guide for the complete process and verification methods. |
Performance values per RivetKing Rev. B test data (May 2023), tested in zinc-plated steel installed in flat sheet stock under laboratory conditions. Actual performance in your application varies with panel material, hole tolerance, installation, and environmental factors. Reference only — not for use as design loads without independent validation. See full performance reference and disclaimer.
Manufacturer Cross-References
| Manufacturer | Part Number |
|---|---|
| RivetKing | 31C1IKFSS |
| Industrial Rivet & Fastener | 31C1IKFSS |
| AVK / Atlas / Marson / Sherex | Equivalent versions available — call for specific cross-reference |
| Brighton-Best (BBI) | (BBI crossover available — call for cross-reference) |
Searching for a different brand? Eugene Fastener can cross-reference RivetKing IKF parts to AVK, Sherex, POP/Avdel, Goebel, and other major rivet nut manufacturers. Call us with any part number for a same-day match.
Related products: Need a different grip range? See the other 5/16-18 IKF rivet nuts in our catalog. Need a different material? Available in steel yellow zinc, aluminum, and 18-8 stainless. Looking for the installation tool? See our Rivet Nut Tool Selection Guide.
Helpful resources: Selection Guide · Drill Bit & Hole Size Chart · Tool Selection Guide · How to Install · Rivnut vs. Plus / Jack / Well / PEM Comparison.
In stock at Eugene Fastener & Supply. Shipping nationwide. Same-day shipping on orders placed before 2pm Pacific.
| Diameter | 5/16 |
| Thread Pitch | 18 |
| Material | Stainless |
| Min Grip | 0.027 |
| Max Grip | 0.150 |
| Hole Diameter | 0.531 |
| Finish | Plain |
| Thread Type | Coarse |