Lot of 16 9/16"-18 Serrated Hex Flange Nuts Black for Trailer U-Bolt Hardware
Customer-friendly full tandem-axle quantity for trailer U-bolt service using sixteen replacement nuts across four tie-plate positions.
Overview
This listing is for a lot of sixteen black serrated hex flange nuts for trailer suspension and U-bolt hardware service. This quantity is ideal for tandem-axle repairs where two axles commonly use eight U-bolts and sixteen threaded ends total. Each nut uses a 9/16"-18 fine thread and a serrated flange designed to bite into the mating surface while spreading clamp load across the contact area.
R&P Service Insight
This is the kind of quantity that makes sense when a customer wants to service the whole running gear instead of piecing together one side at a time.
- Tandem Axle Coverage: Sixteen nuts covers two axles using eight U-bolts total.
- Serrated Locking: Each nut is built to grip the mating surface directly for better resistance to loosening.
- Cleaner Repair: Replacing the full nut count helps avoid mixing worn hardware with new components.
R&P Knowledge Hub
Compatibility: Designed for 9/16"-18 threaded studs or U-bolts, including UB-R303 and similar matching trailer hardware.
Vehicle / System Fit: Trailer suspension, axle, spring, tie-plate, and U-bolt hardware applications using matching 9/16"-18 threads.
Installation Notes: Verify thread pitch, contact surface condition, and mating hardware before tightening. Serrated flange nuts should seat directly against the mating surface so the serrations can grip correctly.
Performance Insight: The serrated flange design spreads load and helps resist rotation, which is useful in trailer applications where clamp retention and service reliability matter.
R&P Repair Insight
If you are replacing U-bolt hardware across a tandem-axle setup, replacing all sixteen nuts at once is often the cleaner and more consistent repair approach.
- Check the Thread: These nuts are for 9/16"-18 threads and are not interchangeable with other 9/16" thread pitches.
- Check the Surface: Serrations need a clean, solid mating surface to lock properly.
- Check the Quantity: This lot of 16 is ideal for two axles using eight U-bolts and four tie-plate positions total.
Features
Lot of 16 Quantity
Practical quantity for one complete tandem-axle U-bolt nut replacement set.
9/16"-18 Fine Thread
Matches 9/16"-18 threaded studs and U-bolts in compatible trailer hardware applications.
Serrated Flange Design
Built with a serrated flange to improve grip at the mating surface and help resist loosening.
Black Finish
Finished in black for a clean hardware look suited to trailer running gear service work.
Specifications
| Specification | Detail |
|---|---|
| Part Number | FPN916L-LOTOF16 |
| Product Type | Lot of 16 serrated hex flange nuts |
| Application | Trailer suspension, axle, tie-plate, and U-bolt hardware |
| Material / Finish | Black finish |
| Thread Size | 9/16"-18 UNF |
| Flange Diameter (B) | Approx. 1.10" |
| Across Flats (F) | Approx. 0.86" |
| Across Corners (G) | Approx. 0.99" |
| Overall Height (H) | Approx. 0.48" |
| Hex Height (J) | Approx. 0.32" |
| Flange Thickness (K) | Approx. 0.12" |
Fitment / Application
| Category | Details |
|---|---|
| Vehicle / System | Trailer suspension and axle hardware systems |
| Primary Fit | 9/16"-18 threaded studs and U-bolts |
| Secondary Fit | UB-R303 and similar applications using the same thread specification |
| Service Quantity | Ideal for tandem axle service using eight U-bolts and sixteen required nuts |
| Notes | Verify thread pitch and application before ordering. Do not assume fit by diameter alone. |
Technical Diagram & Direct Measurement Table
The diagram below and the table beside it refer directly to the same measured callouts. This working version uses only the applicable dimensions shown on your diagram: A, B, F, G, H, J, and K.
| Diagram Callout | Measurement Reference | Value |
|---|---|---|
| A | Thread Size | 9/16"-18 UNF |
| B | Flange Diameter | Approx. 1.10" |
| F | Across Flats | Approx. 0.86" |
| G | Across Corners | Approx. 0.99" |
| H | Overall Height | Approx. 0.48" |
| J | Hex Body Height | Approx. 0.32" |
| K | Flange Thickness | Approx. 0.12" |
| Ref. | Nominal Hex Size | 7/8" |
| Ref. | Nut Style | Serrated hex flange nut |
| Ref. | Finish | Black |
| Ref. | Known Fitment | Fits UB-R303 U-bolt |
| Ref. | Pack Quantity | 16 nuts for tandem axle service |
Included Components
| Quantity | Item |
|---|---|
| 16 | 9/16"-18 serrated hex flange nuts |
| Part Number | FPN916L-LOTOF16 |
| Included | Black finish |
| Included | Serrated flange design |
| Service Use | Tandem axle quantity for eight U-bolts / sixteen threaded ends |
| Not Included | U-bolts, tie plates, washers, springs, axles, or other mounting hardware |
