How to clean the hexagon inside the cylindrical head?

Cleaning the inner hexagon of the cylindrical head (usually referring to the screw hole of the inner hexagon screw) is a very practical problem. Accumulated dust, oil stains, rust, or old thread glue can cause the hex wrench to fail to fully insert or slip, affecting disassembly and fastening.

Firstly, basic cleaning (for soft dirt such as dust and oil stains)

1. Compressed air (preferred method)

Tools: Compressed air tank (the type used for computer dust cleaning) or air pump.

Method: Aim the nozzle at the inner hexagonal hole and spray briefly and forcefully a few times. It is best to cover the other side of the hole with a cloth or hand to prevent dirt from splashing. This is the most effective and non-destructive cleaning method.

2. Toothbrush and cleaning agents

Tools: old toothbrush, pointed brush, combined with carburetor cleaner WD-40、 Alcohol or gasoline.

Method: Spray a small amount of cleaning agent (WD-40 also has rust removal function) into the hole, repeatedly brush every corner of the hole with a toothbrush or pointed brush, then dry with a cloth or blow dry with compressed air.

3. Needles or pins

Tools: sewing needles, pins, or specialized precision hooks.

Method: Carefully use a needle tip to remove stubborn oil sludge or foreign objects from the corners of the hole. Attention: The action should be light to avoid the needle tip breaking inside the hole.

Phase 2: Deep cleaning (for hard dirt such as rust and thread glue)

If the hex wrench still cannot be inserted or turned after basic cleaning, it indicates that there is more stubborn dirt inside.

1. Special screw extractor (anti tooth tap)

Tool: A set of left-hand (anti tooth) screw extractors, usually including models suitable for different sizes of hexagonal holes.

Method: Choose a extractor slightly smaller than the hexagonal hole.

Insert the extractor into the hole and strike it in the opposite direction with a hammer (left rotation is counterclockwise). The vibration of knocking can shatter some rust, and the anti tooth design will tightly bite the residue inside the hole when you rotate counterclockwise, bringing it out.

This is a professional method for cleaning stubborn foreign objects and removing broken screws.

2. Strike with a small hammer

Tools: a small hammer, a properly sized hex wrench, or a discarded hex wrench.

Method: Insert the wrench firmly into the hole and gently tap the end of the wrench with a small hammer. The vibration of knocking can effectively shake the rust and colloids inside the loosening hole. Tap a few more times and then try to rotate. If the wrench slips, switch to method 1.

3. Heating treatment (for thread glue)

Tool: Hot air gun or small spray gun (heat around the screw to avoid directly burning the screw head).

Method: High temperature can soften or decompose most thread adhesives (such as Loctite screw adhesives). After heating, try to turn it with an Allen wrench while it is still hot. Be careful! Wear gloves and keep away from flammable materials. Some screw connection components may deform or change performance due to heating.

4. Penetrating lubricating oil

Tools: Professional penetrating lubricants such as WD-40 Specialist, rust inhibitor, etc.

Method: Spray fully into the hole and wait for a period of time (15 minutes to several hours) to allow the liquid to fully penetrate into the rust cracks, providing lubrication and loosening. Then try to twist it using method 2 (tapping).

Phase 3: Final resort (when the hole is damaged or the above methods are ineffective)

1. Drilling

Tools: Hand drill, suitable drill bit (usually slightly smaller than the hexagonal hole).

Method: Carefully drill a hole in the center of the hole to remove rust, glue, and some screw materials inside the hole. This is a destructive method, which may require the use of larger screws or re tapping afterwards. High technical requirements, non professionals are not recommended to operate.

Summary and Suggestions for Cleaning Steps

Prevention is better than cure

Cleaning before use: Ensure that the inner hexagonal hole is clean before installing new screws.

Apply anti rust oil: In damp or rust prone environments, a small amount of butter or anti rust oil can be applied to the screw holes.

After use protection: When the device is stored for a long time, the screw holes can be sealed with tape to prevent dust and moisture from entering.

Use appropriate tools: Ensure that the size of the hex wrench is accurate and sharp, and avoid damaging the screw holes due to improper tools.