Most of us have had the misfortune of dealing with stripped screws or screw holes from time to time. When it comes to dealing with a stripped screw, the solution is often to just replace it with a new one. Simple enough right? However, dealing with stripped screw holes, especially in metal, can be quite a headache. That’s where this article can help. We dive into 3 different methods for how to fix a stripped screw hole in metal.
Choosing the Right Method to Fix a Metal Screw Hole
Fortunately, there are several options available, it’s just a matter of finding the right method that works for you. Choosing the best method for you will depend on your level of experience and tools needed for the project. So, let’s dive in!
Method #1) Use a Larger Screw
The first method for fixing a stripped screw hole in metal is to simply use a larger screw. While this is the simplest method, it may not always work. For instance, if you’re pressed for space and need to maintain the same diameter, then you may need to look at one of the other methods. Another factor to consider is what you’re attaching to metal. Does it allow for a larger screw? If neither of these are factors, then we suggest starting with this method.
Method #2) Create New Threads with a Tap and Die Set
The second method is using a Tap and Die set. This is probably one of the most common methods for repairing a stripped screw hole in metal. It works best with a drill press to ensure a nice, even hole, though it is not necessary. If you don’t have a Tap and Die set on hand, here are a few that we recommend:
Our Top Picks for Best Tap and Die Set
What You Need:
Tap and Die Set with common SAE sizes and Drill Press (optional).
Step 1) Determine Hole Diameter and TPI (Threads Per Inch)
The first, and most important step in the Tap and Die method, is determining the hole diameter. You can do this by either measuring the inner diameter of the screw hole or by finding a screw that fits and determining the diameter that way. Once you have these measurements, you’ll need to get the thread count. To determine the thread count, you need to count the number of thread gaps within one inch of the length of the screw.
Step 2) Drill the New Thread Hole
Now it’s time to drill the new hole before tapping. If you have a drill press, it’s recommended to use that for a nice, straight hole. If the metal that you’re drilling into is very thin, it is less important to use a drill press. It’s best to start with a clean pilot hole before adding the threads. This helps to get rid of any uneven spaces and makes it easier for the tap to locate properly. The pilot hole should be slightly smaller than the tap bit and/or screw you will be using.
Step 3) Tap the New Thread
Start working the tap into the pilot hole to start the threading process. It’s best to use oil or lubricant to help make the process easier and also keep the whole cleaner. If you’re using a ratcheting tap handle, slowly work the tap into the hole about a half of a turn, back it up a quarter turn, and then repeat until you’ve reached the bottom of the pilot hole. This ensures clean-cut threads and keeps shavings from interfering.
Step 4) Install the Screw Into the New Threads
Now it’s time to install the screw into your new threads. Start slowly and be sure that the screw is going in without resistance. Run the screw to the bottom to make sure your depth measurements were correct.
Method #3) Install a Helicoil Insert
One of the most durable and long-lasting ways to repair a stripped screw hole in metal is with a Helicoil insert. The goal of a Helicoil insert is to provide new threading to the hole to allow the new screw something to grab onto securely. Helicoil inserts provide you with the versatility that you need to address almost any sized hole.
What You Need:
Helicoil insert, drill, tap set, and old screw if available
Step 1) Prepare the Old Hole
The first step in this process is to prepare the old hole. For a Helicoil insert, this means drilling out the hole to remove the old threading. This allows for a blank slate upon which you can apply new threading for your new screw. The thread repair kit that you purchase will specify the drill size that you should use for this step.
Step 2) Find the Right Size Helicoil Insert
One of the most essential parts to having success installing a Helicoil insert is determining the right size. To determine the right size, it is generally recommended that the old screw that occupied the hole be measured using the proper tools. This will give you the right measurement for the spacing and length of the insert that you use.
Step 3) Create New Threads with a Tap Set
Using a tap set, tap the hole to prepare for the installation of the insert. Again, ensure you have the right size Use your drill to insert the tap to allow the Helicoil insert with a surface to latch onto.
Step 4) Install the Helicoil Insert
Once the tap is inserted, install the Helicoil insert into the tap. Use the insert tool to put the Helicoil insert as far into the tap as you need it. Once you have the insert in far enough, remove the installation tool, leaving the Helicoil insert.
Step 5) Remove the Tang
Break off the tang of the Helicoil insert at the notched portion of the tang on the insert. Use an insert to break off the tang and tweezers or magnet to retrieve the tang that you broke off. For all Helicoil inserts, the tang must be removed.
How to Fix a Stripped Screw Hole in a Metal Door
To fix a stripped screw hole in a metal door, we first recommend trying a larger screw. If this is not possible, you can try an epoxy in the hole to help grab the screw. Lastly, using an anchor may be an option, either plastic or a soft metal like lead that will conform to the hole.
How to Fix a Stripped Screw Hole in Sheet Metal
Because sheet metal is so thin, we recommend trying a hammer and dolly to try to smash the hole into a smaller diameter. This method is often used for auto body repair, but would be a great first option for a stripped screw hole in sheet metal. A couple of other options include: using plumbers tape around the screw threads, JB Weld, or again… a larger screw.
How to Fix a Stripped Screw Hole in Aluminum
In addition to some of the methods mentioned above, such as drilling and tapping, Helicoil inserts, JB Weld, and using a larger screw, we offer another suggestion for Aluminum. Using copper wire strands, which is usually softer than most aluminum, to compress into the old threads seems to be a preferred method by many. This provides a secure and long-lasting hold to help keep your screw in place.
How to Fix a Stripped Bolt Hole in Metal
How to Measure the Hole Depth
The easiest way to measure the depth of a screw hole is to simply find something with a smaller diameter, such as a wooden skewer stick. You’ll then place the stick into the screw hole and mark the stick at the surface with a pencil. This will allow you to measure from the tip of the stick to your pencil mark, thus giving you the depth of the hole.
How to Measure the Hole Diameter
The old-school way of measuring a screw hole diameter is by using an inside caliper and then measuring that distance with a micrometer. This method is a little dated and there are now easier ways to get the measurement. If that’s all you have on hand, it’ll work. However, we find it easier to use a hole gauge and then measure that with a micrometer. In the end, either method will work just fine and should give you an accurate measurement.
Do You Need to Clean and Lubricate the Hole?
Yes, it is important to properly clean and oil/lubricate the hole when you’re drilling and tapping. This helps to ensure a nice, clean hole and keeps small metal shavings from interfering with the new threads. Also, the lubricant helps to provide a smooth, easier cut.
The Bottom Line
Most of these methods can work for just about any stripped screw hole project. Sometimes, it’s a matter of using what you have on hand. However, using the right tools can make your job easier and eliminate a lot of frustration. Whichever method you choose, we wish you the best of luck!