Fixing a Stripped Screw Hole in Metal Is a Beginner Task for Most DIYers. Here’s Everything You Need to Know to Fix a Stripped Screw Hole in Metal at Home.
DIY Difficulty Level: Beginner
Time Required: 30 minutes to an hour
Tools & Materials:
Keep in Mind
To save yourself some money, don’t purchase all of these materials at once. Which materials you’ll need depends on what method you use to fix the stripped screw hole.
Be sure to analyze what this particular screw’s job is. If it’s there to hold something vital in place, you may not want to use the easiest and least durable approach to fixing the screw hole. Instead, opt for a more reliable method. However, if the screw’s job is nonessential, you may be able to cut some corners to make the repair job easier. It’s all about what type of resources — including your time — you’re willing to spend on the project and whether or not the screw and screw hole plays an important part in maintaining structural integrity.
The type of metal is important to keep in mind as well. You wouldn’t use a tap-and-die approach to fixing a stripped hole in sheet metal, for example. Analyze the materials to decide which is the correct method that you should use to fix the problem.
How To Fix a Stripped Screw Hole in Metal
There are a few methods you can use to reverse the damage of a stripped screw hole in metal. Consider the pros and cons of each option to decide which is the best route for you to take.
The Easiest Option: Use Larger Screws
If you’ve got a bigger hole, use a bigger screw. The easiest option is just to use a larger screw to make up for the larger stripped hole. This is perhaps the least elegant method of fixing a stripped screw hole, but if you can get away with it without compromising structural integrity, it’s by far the easiest option. This method works well for sheet metal since you wouldn’t be creating new threads as in the other methods described here anyway.
The Artisan’s Option: Use a Tap and Die Set
If you want to take a more professional approach to reverse a stripped screw hole, you can use a tap and die set. The costs of these sets vary, but you can find some reasonably priced options if you think you won’t be using them very often.
Using a tap and die set to make new threads is much more involved than simply using a larger screw. You’ll first need to find the diameter of the hole by measuring the hole itself or a screw that fits into it. You should do this with calipers, which may or may not have come with your tap and die set.
The next measurement you’ll take is the pitch of the thread, which is how many narrow or wide the gap between each screw thread is. This second number is represented as TPI, or threads per inch. You’ll need to know how many thread gaps the screw has in one inch. If the screw is shorter than an inch, you may have to do some simple multiplication to come up with the correct TPI. With metric bolts, this measurement is threads per millimeter.
Use these bits of information to figure out what size tap you need to use to make the threads in your hole. Your tap and die set may have come with a tap drill chart. You can visit this page for a detailed size chart. Once you find the appropriate size of tap you need, it’s time to get down to business.
If you’re going to put a larger screw into the hole, you may need to enlarge the hole to a diameter slightly smaller than the new screw. If you do this too much, you’ll have to go up to an even larger screw.
Use your tap to cut new threads in the hole to the appropriate size. Use oil or some other lubricant to make cutting the threads easier Thread the hole with your tap until it’s clean through to the other side of the metal or down to an appropriate length for the screw.
Now take your screw and work it into your newly threaded hole to see if it’s a fit. Take care to keep the screw straight and don’t go too fast — you may strip your brand-new screw hole. If everything went according to plan, you should have a good screw hole with brand new threads.
The Mechanic’s Option: The Helicoil Method
You can also use a helicoil insert to give new life to your screw hole. Helicoil inserts fit inside of drilled holes and provide screws with a threaded surface to hold on to. Heli-Coil brand inserts are made by Stanley, who invented them, but you’ll find the term helicoil used as a proprietary name, such as Kleenex, to refer to this type of product from other companies.
To insert the coil, you’ll need a special tool that screws it into place. You may need to smooth out the walls of the hole to slide the insert into it. Once it’s firmly inside the hole, tighten your screw inside the helicoil, which should expand to grip the hole while providing your screw with threads to hold onto. Be sure to purchase a helicoil that matches the size and thread pitch of the screw you’re trying to use for the hole.
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