A screw hole can be damaged every now and then. It can occur due to the forced insert of the screw or due to extra load-pressure on the screw as well. Either way, you have to deal with the issue and take actions to fix it for screwing on it over again.
Now the question of the moment is- how to fix a stripped screw hole in a metal? Well, when the damaged or worn out screw hole is in a metal like aluminum, things become a bit complicated. Because re-cutting the threads on metal without reaching damage to is quite an operational process.
But worry not. We’ve got you in there. This article contains two of the most sophisticated methods of fixing up a screw hole in metal. Take a moment of a break from whatever you are doing, and explore the whole article-
Table of Contents
Steps of Fixing A Stripped Screw Hole in Metal
Here we are with the steps of the task we are up to. We hope that you are definite about the whole you want to work on, and decided that the hole needs to be fixed.
If so, grab the essential tools and step into the actions below-
Method 1: Using A Tap and Die Set
The first method on how to fix a stripped screw hole in metal is through using a tap and die set. All it requires is the correct measurement of the screw hole that you are dealing with and a good quality tap handle.
Once you have got both of them, the process becomes easy. Let’s have a look-
Step 1: Determine the Outer Diameter and the Thread Count of the Hole
At first place, we will take the measurements in the right way to calculate the size of the hole. By measurements, we mean the outer diameter and the thread count.
To measure the diameter of the hole, you can measure the width of the hole, or you can measure the width of the screw or both that goes into it. The second one is a better and easier choice.
To measure the thread count, you have to pick up a screw that goes into the hole and measure its number of threads. Measure the number of threads for unit inches across the length of the screw.
Step 2: Install The Tap Into The Tap Handle
Right after you have got the right measurements from step 1, you should be able to select the right tap size. And also, install the tap into its handle.
While dealing with this step, don’t touch the taps with bare hands, specially when you’re not used to it. These are sharp enough to bring on accidental incidents.
Step 3: Insert The tap into The Hole
Now, set the right tap to the tap handle, and put it over the hole or thread that you are supposed to fix.
There are two sorts of screws in there- the right-handed screws and the left-handed screws. Most of the screws are the right-handed screws, and we assume you are dealing with one as well.
However, start to rotate the tap into the screw once you are done with inserting the tap into the hole.
In case the screw is left-handed(which happens very rarely though), you should rotate the tap handle counter clockwise.
Step 4: Rotate According To the Rule
Now, you have to keep rotating the tap handle for 3/4th of the screw hole length. Once you are done with the 3/4th of the hole, change the direction of rotation from clockwise to counter-clockwise.
Keep rotating counter-clockwise for rest of the 1/4th portion of the hole.
Step 5: Keep Repeating with the Process
Now, when you are done with rotating the tap clockwise once and counterclockwise later, check whether the screw is getting into the hole or not. If it’s negative, you should repeat the previous step once again until you can insert the screw by rotating clockwise anymore.
Once you have made sure a perfect placement of the screw, we are done with the process. Take the tap handle out of the hole.
Method 2: Using A Helicoil Insert
In case a screw hole is brutally damaged or bent, it’s better to use this method to drill out the original one and create a new one over it. This can be done with the help of a kit called the helicoil insert. It’s not expensive, and it helps you out to fix this issue forever.
Once you have got the right helicoil kit in hands, here you go with the steps-
Step 1: Prepare The Damaged Hole
Before inserting the helicoil insert, you need to make sure that there are no dust particles inside in the damaged hole.
To make that sure, you can put some brake oil into the damaged hole and blow it out for further assurance. This will also help it to have perfect lubrication as well.
Step 2: Get The Right Size of The Helicoil Insert
Now it’s time to get the right size of the insert and use that into the hole. To understand the correct size of the insert, you can follow this way-
The depth of the helicoil insert would be at least ¼-½ turn below the top of the original one. Once you’ve got a helicoil of such size, remove the fastener fro the hold and get ready for the next step.
Step 3: Drill The Old Screw Hole
At this point, take a drill machine and a correct size of the drill bit to drill out the existing(damaged) screw hole. While you are doing the drilling, make sure that the drill bit reaches right through the bottom of the hole. Otherwise, it will be troublesome to install the new helicoil insert.
Thinking of the correct drill bit size? Well, if you are using a helicoil insert of ⅜ inches, you will be needing a 25/64 inches drill bit.
Step 4: Thread It with A Tap Set
Once again, you will be needing a good quality tap set of correct size at this point. As you know, tap set helps to cut threads on a particular hole, and that’s what we need at this step.
Take the right measurement and follow the steps in the last method to get some idea on how to cut threads with a tap and due to insert properly.
Step 5: Install The Helicoil Insert
Based on what type of threads you have cut, there can be two options-
- Coarse thread cut.
- Fine thread cut.
To install a helicoil insert, we need to stick to the fine thread cuts. If so, you have to install the pre-coil tool that comes with the helicoil insert. The pre-coil tool is too that compresses the insert to the correct size. As a result, the insert stays in the correct form.
So, thread-cut the tool into the insert inside the pre-coil body. Now, keep spinning the installer tool unless you find it fully threaded.
The insert is installed at this point, but the job is not over yet.
Step 6: Remove The Tang
For all kind of tanged insert, the tang must be removed from it. To do that, you have to use a punch. While choosing the right punch, make sure that it fits snugly into the helicoil insert we are working with.
Take the punch and put it in the insert until it reacher the tang. When it reacher the point, hit the punch with the help of a hammer. This will finally pop out the tang.
Frequently Asked Questions (FAQ)
Question: How can I measure the hole diameter?
Answer: You can measure the diameter of the screw that goes in and that would be the diameter of the screw hole as well.
Question: How can I measure the hole depth?
Answer: The depth of the hole is also measured in the same way as the diameter. Just measure the height of the screw that goes in the hole and you will get the depth of the hole.
Question: Do i need to lubricate the hole before fixing it?
Answer: Yes, a bit of blowing out and some brake oil would do a fantastic job of lubrication. Eventually, lubrication will make the fixing process easier.
You see, none of the processes are quite easy to deal with for a beginner. In case you are completely new to this sort of tasks, we would recommend you to do the process under the supervision of a professional.