Removing screws designed to be permanent or those that have become stripped can be challenging, but several techniques exist to tackle them.
When dealing with a screw that appears "non-removable," you typically face a screw designed for one-way installation (like a one-way screw) or one that is damaged or installed in a way that prevents conventional removal. The specific method depends on the type of screw and the situation.
Techniques for Removing Difficult Screws
Different types of screws require different approaches. Here are some common methods:
Removing One-Way Screws
One-way screws are designed with angled slots that allow a screwdriver to turn them in only one direction (clockwise to tighten). Removing them requires a method to grip the head and turn counter-clockwise.
- Using Locking Pliers: An effective method is to create a strong grip on the head of the screw. This can be done by using locking pliers around the screw. Once you have a firm grip on the screw head, simply turn the pliers counter-clockwise to remove the screw.
- Using a Screw Extractor: A specialized tool called a screw extractor can be used. You drill a small hole in the center of the screw head, then insert the extractor (which has reverse threads) into the hole. As you turn the extractor counter-clockwise, it bites into the screw and unscrews it.
- Cutting a New Slot: If the screw head protrudes, you might be able to use a hacksaw or a rotary tool with a cutting disc to cut a new, deeper slot across the head. Once a straight slot is created, you can use a flathead screwdriver to turn the screw.
Removing Stripped Screws
A common issue making a screw "non-removable" is a stripped head, where the driver bit can no longer grip the slots or recess.
- Rubber Band Method: Place a wide rubber band over the stripped screw head before inserting the screwdriver. The rubber may fill the gaps and provide just enough grip to turn the screw.
- Screw Extractor: As mentioned for one-way screws, an extractor is highly effective for stripped screws.
- Pliers: If the head is accessible, gripping it with locking pliers or even needle-nose pliers can work, similar to the method for one-way screws.
- Drilling: In extreme cases, you may need to drill out the screw head entirely. Use a drill bit slightly larger than the screw shank. Once the head is drilled off, the material held by the screw can be removed, and the remaining screw shank can often be removed with pliers.
Removing Tamper-Proof/Security Screws
These screws have unique heads requiring special tools. Examples include Torx Security, Tri-Wing, Spanner, and Snake Eye.
- Matching Bit: The primary method is to use the correct, specialized screwdriver bit designed for that specific security pattern.
- Screw Extractor: For some types, a screw extractor can still be used if the head allows drilling.
- Modifying the Screw: In some situations, you might be able to use pliers or a cutting tool (like a Dremel) to modify the head enough to grip it or cut a new slot, but this is often a last resort.
Summary of Methods
| Screw Type | Recommended Removal Methods | Tools Often Needed |
|---|---|---|
| One-Way Screw | Locking Pliers (grip head), Screw Extractor, Cut New Slot | Locking Pliers, Screw Extractor Kit, Drill, Hacksaw/Rotary Tool |
| Stripped Screw | Rubber Band, Screw Extractor, Pliers (if head accessible), Drill Out Head | Rubber Band, Screw Extractor Kit, Drill, Various Pliers |
| Tamper-Proof | Matching Security Bit, Screw Extractor (if possible), Modify Head (last resort) | Specific Security Bit Set, Screw Extractor Kit, Pliers, Drill |
Important Note: Always use appropriate safety gear, such as eye protection, when attempting to remove stubborn screws, especially when drilling or using cutting tools. Choose the least destructive method first.
