Yes, you absolutely can install rivnuts without a specialized tool, though the process requires more manual effort and careful selection of improvised tools. Installing rivnuts manually can be done using common household items or basic hardware, making it a viable option when a dedicated rivnut tool (or rivet gun) is unavailable. This guide will show you the best methods for rivnut installation without tool situations.
Why Install Rivnuts Without a Tool?
People often look for ways of rivnut installation without tool for several reasons. Maybe you need a quick fix on a project. Perhaps you are working remotely where your proper tools are not handy. Or, sometimes, the cost of a specialized manual rivnut setter substitute seems too high for a one-time job. Knowing installing rivnuts manually techniques gives you flexibility.
What is a Rivnut and Why is it Useful?
A rivnut, also called a rivet nut or blind rivet nut, is a type of fastener. It lets you add a strong, threaded hole to thin material. Think of it like a nut that you can install from only one side. This makes them great for sheet metal, plastic, or hollow structures. They offer a much stronger thread than just tapping the material itself.
Preparing for Manual Rivnut Setting
Before starting any DIY rivnut installation, good preparation saves a lot of trouble later.
Material Selection and Sizing
First, match the rivnut size to your material thickness and bolt size. This is crucial for a secure installation, whether using a tool or not.
| Rivnut Type | Recommended Hole Size (Inches) | Grip Range (Material Thickness) (Inches) |
|---|---|---|
| M6 | 0.330 – 0.335 | 0.030 – 0.125 |
| 1/4-20 | 0.258 – 0.263 | 0.040 – 0.150 |
Hole Preparation
The hole size matters a lot when rivnut setting without a gun. If the hole is too big, the rivnut will just spin. If it is too small, it won’t fit.
- Measure: Use calipers to get an accurate measurement of the material thickness.
- Drill: Drill the hole using the exact size specified by the rivnut manufacturer. Use a sharp drill bit. A clean hole means a better grip.
- Deburr: Smooth the edges of the hole. Sharp edges can damage the rivnut’s threads during setting.
Methods for Installing Rivnuts Manually
Installing blind rivets without tool assistance requires you to mimic the pulling action of a proper setting tool. The goal is to pull the mandrel (the center threaded shaft) out just enough to collapse the body of the rivnut against the backside of the material.
Method 1: The Bolt and Nut Method (The Most Common Alternative)
This method is the closest you can get to using a proper setting tool with common hardware. This is a very popular choice for hand setting rivnuts.
Required Items:
- The correct size bolt that matches the rivnut’s internal thread (e.g., an M6 bolt for an M6 rivnut).
- A nut that fits the bolt.
- A washer that fits over the bolt head, but is smaller than the rivnut head.
- A second nut or a spacer (optional, for better control).
Step-by-Step Process:
- Insert the Rivnut: Place the rivnut into the prepared hole. Make sure its head sits flush on the surface.
- Assemble the Puller:
- Slide the first washer onto the bolt.
- Thread the rivnut onto the bolt.
- Place the second washer (or spacer) on the bolt, resting against the rivnut head. This washer prevents the bolt head from crushing the rivnut head inward.
- Apply Tension: Hold the bolt head steady. Thread the loose nut down until it makes firm contact with the washer that is sitting on the rivnut head.
- Tighten and Collapse: Slowly tighten the second nut against the first assembly. As you tighten the nut, it pushes the bolt deeper into the rivnut. This action pulls the mandrel, causing the tail end of the rivnut to flare out behind the material.
- Check Tension: Keep tightening until you feel a distinct stop. This means the rivnut has fully collapsed. Be careful not to overtighten! Overtightening can strip the internal threads or tear the material.
- Release: Hold the outer nut steady. Unscrew the bolt from the newly set rivnut. If the rivnut spins, you did not set it firmly enough, or the hole was too large.
- Test: Test the new threaded hole with the correct size bolt.
Method 2: Using Two Wrenches for Controlled Tension
This is an alternative rivnut installation method that offers a bit more control than just using nuts and washers, especially if you have access to two adjustable wrenches.
Required Items:
- The correct size bolt.
- Two appropriately sized open-end wrenches or adjustable wrenches.
Step-by-Step Process:
- Setup: Insert the rivnut into the hole. Thread the bolt through the rivnut.
- Grip: Place one wrench firmly on the head of the bolt. Place the second wrench around the body of the rivnut (if possible, using an open-end wrench that fits snugly around the outside edge without slipping).
- Pull: While keeping the wrench on the bolt head stationary (to prevent it from turning), use the second wrench to slowly turn the rivnut body in a tightening direction. This action pulls the mandrel inward.
- Feel the Set: Continue turning until you feel significant resistance. This indicates the back end has flared. Stop immediately when you feel that resistance.
- Remove: Unscrew the bolt.
This method relies on physically holding the body of the rivnut still while the bolt pulls, forcing the crush. This is a form of installing blind rivets without tool if you consider a wrench a basic hand tool, not a specialized installation tool.
Method 3: The Hammer and Punch Technique (Use With Extreme Caution)
This technique should only be considered for soft materials (like thin aluminum or plastic) where the impact force is less likely to cause damage, and only as a last resort for manual rivnut setter substitute. It is risky and often results in cosmetic damage.
Required Items:
- A blunt punch or a piece of metal rod that fits inside the rivnut’s throat but is smaller than the mandrel.
- A hammer.
- A small block of wood placed underneath the material (if possible) to support the area.
Step-by-Step Process:
- Insert Rivnut: Place the rivnut in the hole.
- Position Punch: Insert the blunt end of the punch down the center of the rivnut, resting it lightly on the mandrel tip.
- Gentle Taps: Gently tap the top of the punch with the hammer. The impact transfers force to the mandrel, pulling it up slightly and starting the flare.
- Observe: Check the head after a few light taps. You must stop as soon as the head sits flush. Heavy hammering will shatter the rivnut or deform the material surface badly.
This method is very hard to control and is generally not recommended for high-strength applications where pop rivet tool alternative for rivnuts needs precision.
Deciphering Rivnut Installation Success
How do you know if your rivnut setting without a gun was successful?
A correctly installed rivnut will meet these criteria:
- The head sits perfectly flush against the material surface. There should be no gap.
- The rivnut body is firmly set against the backside of the material. If you try to twist the installed rivnut using the bolt, it should not budge.
- The internal threads are smooth and undamaged, allowing a bolt to thread in easily without binding.
If the rivnut spins or wobbles after setting, it means the collapse was incomplete, or the hole was too large. In this case, removal and replacement are necessary.
Tips for Better Manual Setting Results
When performing hand setting rivnuts, small adjustments make a big difference in the final quality.
Control the Pull Force
The secret to rivnut installation without tool is controlling the force applied. You need just enough tension to crush the back end without pulling the mandrel clean through or stripping the threads. If using the bolt and nut method, turn the setting nut in small increments (quarter turns) and check for resistance frequently.
Material Compatibility
The method that works best depends on what you are fastening into:
- Thick Metal: The Bolt and Nut Method (Method 1) usually works best here because it provides the necessary sustained tension.
- Thin Sheet Metal: Be extremely careful with Method 1. The thin material might deform outwards before the rivnut flares correctly. Adding a rigid backing plate under the material can help distribute the force.
- Plastic or Wood: These materials require very light tension. Method 2 or very light taps in Method 3 might be necessary, as excessive force will crack the material around the hole.
Using Spacers Effectively
In Method 1, the washer used between the setting nut and the rivnut head acts as a critical spacer. Ensure this washer is thick enough so that the bolt head does not touch the rivnut head before the tail has started to flare. This ensures the crushing action happens where it should—on the backside.
Comparing Tool vs. No-Tool Installation
While alternative rivnut installation methods are useful in a pinch, it is important to know what you are sacrificing by not using a dedicated tool.
| Feature | Specialized Rivnut Tool (Gun) | Manual/No-Tool Method |
|---|---|---|
| Speed | Very fast (seconds per unit) | Slow (several minutes per unit) |
| Consistency | High—applies consistent, calibrated pull force | Low—depends entirely on user feel and strength |
| Force Control | Excellent, often includes stroke adjustment | Poor to Moderate, relies on feel |
| Ease of Use | Easy after initial setup | Difficult, requires leverage and practice |
| Best For | Production runs, heavy-duty applications | Quick repairs, one-off jobs, emergencies |
For professional work or high-vibration environments, always opt for a proper tool. For basic DIY rivnut installation, manual methods suffice if done carefully.
Troubleshooting Common Manual Setting Issues
Even with careful attention, manual setting can go wrong. Here are common issues and how to fix them when installing rivnuts manually.
Problem 1: The Rivnut Spins in the Hole
This means the material is not crushed tightly enough around the body of the rivnut.
Fix:
1. Try to tighten the setting bolt/nut assembly further, but watch the head closely for crushing.
2. If it still spins, the hole is likely too big. You may need to remove the failed rivnut (drill it out carefully) and use a slightly larger rivnut, or use an adhesive to secure the loose one if removal is impossible.
Problem 2: The Mandrel Pulls Through (No Flaring)
The mandrel snaps or pulls out without the body collapsing. This often happens when the material is too thin or you didn’t apply enough secondary tension.
Fix:
1. If the mandrel broke, you must remove the broken piece from the threads.
2. Re-attempt the hand setting rivnuts process, ensuring the bolt is fully engaged, and apply more steady tension during the collapse phase.
Problem 3: The Rivnut Head is Deformed or Cracked
This happens from too much force, especially common when using the hammering technique or tightening the nuts too aggressively.
Fix:
1. If the head is crushed inwards but the threads are fine, it might still hold, but its appearance will be poor.
2. If the threads are ruined, the rivnut must be removed and replaced.
Considerations for Different Materials
The technique for rivnut installation without tool must adapt to the material you are working with.
Soft Metals (Aluminum, Thin Steel)
Soft materials deform easily. The goal is to create a bulge at the back without creating a large “washer” effect on the front surface. Use thin washers in Method 1 to limit how far the setting nut can compress the front face. Slow, incremental tightening is key.
Hard Metals (Thick Steel)
Hard materials require significant leverage to overcome their resistance. You may need longer wrenches or a way to brace the bolt head firmly against a solid surface (like a vise) while you use the wrench to turn the setting nut for maximum leverage.
Plastics and Composites
These materials cannot handle high clamping forces. For plastics, the grip range specification of the rivnut is vital. Use the lightest touch possible. Often, the Bolt and Nut method (Method 1) works best here because the turning motion is easier to control than a direct impact (Method 3). When installing rivnuts manually in plastic, remember that the plastic itself is being compressed to hold the fastener.
Removing a Poorly Installed Rivnut
Sometimes, even the best effort at rivnut setting without a gun results in a failure. How do you get it out?
- Drill Out the Mandrel: If the mandrel is stuck inside, use a drill bit the same size as the mandrel (not the body threads) and carefully drill it out until the mandrel section is gone.
- Drill the Body: Select a drill bit that is slightly larger than the inner thread diameter but smaller than the outer body diameter of the rivnut.
- Destroy the Grip: Slowly drill down through the body of the rivnut. This destroys the crimped base holding it in place.
- Extraction: Once the material around the edges is thin enough, the remaining shell can usually be picked out with a sharp scribe or a small screwdriver. If the hole size was correct, the shell should collapse inward slightly, making removal easier.
This meticulous process is why getting the rivnut installation without tool right the first time is so important.
Conclusion on Manual Setting
While a dedicated tool makes installing blind rivets without tool a distant memory for professionals, it is definitely possible for the DIY enthusiast. The Bolt and Nut method stands out as the most reliable pop rivet tool alternative for rivnuts when you need a strong, threaded connection without specialized equipment. Remember that patience and slow, controlled force are your best assets when installing rivnuts manually. Practice on scrap material first to get a feel for the correct setting point before working on your final piece.
Frequently Asked Questions (FAQ)
Q: Can I use a standard pop rivet tool for rivnuts?
A: No. A standard pop rivet tool is designed to pull the mandrel on a hollow, smooth-shank rivet. Rivnuts have internal threads. Using a pop rivet tool will only pull the mandrel slightly, which is insufficient to properly collapse the body of the rivnut against the backside of the material. You need a tool that grips the internal threads, which is why alternative rivnut installation methods focus on simulating that internal grip.
Q: What is the risk of damaging the material when doing hand setting rivnuts?
A: The main risk is over-tightening. If you apply too much tension during rivnut setting without a gun, you can crush the material around the head (causing a dent) or strip the internal threads of the rivnut itself, rendering the fastener useless. Always tighten slowly and stop immediately upon feeling solid resistance.
Q: Is it possible to install oversized rivnuts by slightly enlarging the hole?
A: This is one of the risks associated with DIY rivnut installation. If you drill a hole slightly too large for a standard rivnut, you must upgrade to the next larger size rivnut designed for that hole diameter. Trying to force a smaller rivnut into an oversized hole will result in a weak connection that spins easily, as the material will not have enough surface area to grip firmly during the collapse.
Q: If I don’t have a bolt matching the exact internal thread size, what is the best manual rivnut setter substitute?
A: If you lack the correct bolt, the next best option is to find a heavy-duty piece of threaded rod that matches the thread count and diameter as closely as possible. If you cannot find a perfect match, using the Bolt and Nut method becomes extremely difficult and risky. In that scenario, Method 2 (using two wrenches to grip the body and manually pull the mandrel up) might be a slightly safer, albeit harder to control, option.