Introduction
Thank you for choosing the Proster 14-inch Professional Rivet Nut Gun Set. This manual provides essential information for the safe and effective use, setup, operation, and maintenance of your new tool. Please read this manual thoroughly before use and keep it for future reference.
Safety Information
Always observe basic safety precautions to reduce the risk of personal injury or damage to the tool. Failure to follow these instructions may result in serious injury.
- Wear Eye Protection: Always wear ANSI-approved safety goggles or safety glasses with side shields when operating this tool.
- Keep Work Area Clean: Cluttered areas invite injuries.
- Use the Right Tool: Do not attempt to force a small tool or attachment to do the work of a heavy-duty tool.
- Avoid Accidental Operation: Ensure the tool is properly set up before beginning work.
- Maintain Tools With Care: Keep tools clean for the best and safest performance. Follow instructions for lubricating and changing accessories.
- Check for Damaged Parts: Before any use, carefully check the tool for any damaged parts. Any part that is damaged should be properly repaired or replaced by an authorized service center.
- Keep Children Away: Do not let children handle the tool.
- Do Not Overreach: Keep proper footing and balance at all times.
Package Contents
Your Proster Rivet Nut Gun Set includes the following items:
- 1 x 14-inch Professional Rivet Nut Gun (Double Handle)
- 6 x Metric Mandrels (M3, M4, M5, M6, M8, M10) - Note: M6 Mandrel is pre-installed on the tool.
- 1 x Multifunctional Spanner/Wrench
- 1 x Durable Storage Case
- 150 x Rivet Nuts:
- M3 x 9mm (40 pieces)
- M4 x 11mm (40 pieces)
- M5 x 13mm (30 pieces)
- M6 x 15mm (20 pieces)
- M8 x 18mm (15 pieces)
- M10 x 21mm (5 pieces)


Specifications
| Feature | Specification |
|---|---|
| Manufacturer | Proster |
| Model Number | PST157-US |
| Item Weight | 2.2 Kilograms |
| Package Dimensions | 41.1 x 19.3 x 6.7 cm |
| Color | Yellow |
| Material | Steel Alloy |
| Riveter Gun Type | Rivet Nut Guns |
| Power Type | Hand Riveters |
| Tool Length (closed) | 350mm / 13.8 inches |
| Tool Width (closed) | 120mm / 4.7 inches |
| Tool Width (open, approx.) | 550mm / 21.7 inches |
| Handle Material | TPU Rubber-Coated |
| Batteries Included | No |
| Batteries Required | No |

Setup
Changing Mandrels
The rivet nut gun comes with an M6 mandrel pre-installed. To change to a different size mandrel, follow these steps:
- Use the provided multifunctional spanner/wrench to loosen the nut on the tool head by turning it counter-clockwise.
- Remove the loosened nut from the mandrel.
- Use the sharp point of the spanner to detach the cross pin that secures the mandrel.
- Pull the current mandrel out. Insert the desired size mandrel and secure it by reattaching the cross pin and tightening the nut clockwise with the spanner.

Operating Instructions
Follow these steps to properly use your rivet nut gun:
- Prepare the Tool: Ensure the correct size mandrel is installed for your rivet nut. Make sure the arms of the tool are completely opened.
- Install Rivet Nut: Thread the appropriate rivet nut onto the mandrel.
- Insert into Hole: Insert the rivet nut into the pre-drilled hole in your workpiece.
- Rivet the Nut: Press the handles of the rivet gun together firmly and steadily to expand and set the rivet nut in place.
- Tighten (if necessary): Repeat steps 2-4 at least 2-3 times to ensure the nut is fully tightened and securely seated.
- Unload the Tool: After the rivet nut is set, turn the smooth rotary knob (nut retraction device) on the tool head to quickly separate and unload the rivet gun from the set rivet nut.


Maintenance
Proper maintenance ensures the longevity and optimal performance of your rivet nut gun.
- Cleaning: After each use, wipe down the tool with a clean, dry cloth to remove any dust or debris.
- Lubrication: Periodically apply a small amount of light machine oil to the pivot points and moving parts of the tool to ensure smooth operation.
- Mandrel Inspection: Regularly inspect mandrels for wear or damage. Replace worn mandrels to prevent improper rivet nut setting.
- Storage: Store the rivet nut gun and all accessories in the provided durable storage case in a dry, clean environment, away from direct sunlight and extreme temperatures.
Troubleshooting
Here are some common issues and their solutions:
- Rivet Nut Not Seating Properly:
- Ensure you are using the correct size mandrel and rivet nut for the hole.
- Apply firm and consistent pressure when pressing the handles.
- Repeat the riveting action 2-3 times to fully set the nut.
- Mandrel Stuck in Rivet Nut:
- Ensure the nut retraction device (rotary knob) is fully turned to release the mandrel after setting the rivet nut.
- Check for any debris or damage on the mandrel or inside the rivet nut.
- Tool Handles Are Stiff:
- Apply lubricant to the pivot points and moving parts as described in the Maintenance section.
- Clean any accumulated dirt or grime from the joints.
User Tips
- Hole Size: Always ensure the pre-drilled hole size in your material matches the diameter of the rivet nut for a secure fit. A hole that is too large will result in a loose rivet nut, while a hole that is too small will prevent proper insertion.
- Practice First: If you are new to using a rivet nut gun, practice on scrap material to get a feel for the tool and the amount of pressure required to properly set a rivet nut.
- Even Pressure: Apply steady and even pressure to the handles. Avoid jerky movements, which can lead to improperly set rivet nuts or damage to the tool.
- Mandrel Selection: Double-check that you have selected the correct mandrel size for the rivet nut you are using. Using an incorrect size can damage both the mandrel and the rivet nut.
Warranty and Support
Proster products are manufactured to high-quality standards. In the unlikely event of a defect due to faulty materials or workmanship, please contact your seller or Proster customer support for assistance. Please have your model number (PST157-US) and purchase information ready when contacting support.





