Hexlox Insert 4 mm

The Hexlox Insert is placed into the head of a magnetic hex bolt. This blocks access to the bolt for anyone equipped with conventional tools, making it significantly more difficult for thieves to remove your components.

This is how it works:

1. Check size: Insert an Allen key into the bolts you want to secure to determine the correct Hexlox size.
2. Magnet test: Hold a refrigerator magnet to the screw – if it sticks, it is magnetic and compatible with Hexlox.

Question: What is a Hexlox Insert?

Answer: Our main product is an insert for securing existing hex bolts (hexagon socket) on bicycles. These inserts are very small, allowing them to be placed into the bolt sockets.

Hexlox Inserts are available in sizes 4 mm, 5 mm, 6 mm, 8 mm and 10 mm.

Please note! Hexlox Inserts work in magnetic (steel) bolts. If your bolt is non-magnetic (stainless steel, titanium, aluminum) and you insert a Hexlox, it won't work. The insert will eventually fall out. In this case, simply replace your non-magnetic bolt with a regular steel bolt, or use the Hexlox Insert for Non-Magnetic Bolts.

Question: Do I need a special key?
Answer: Yes, the Hexlox Key is sold separately and is required to insert/remove the Hexlox Insert.

Question: How do I find out if my screws are magnetic?
Answer: Hold a refrigerator magnet to the screw. If it sticks, it's magnetic.

Question: Can I get the Hexlox Insert out with a large magnet?

Answer: No, you can't remove the Hexlox Insert with a magnet. We played with the polarity and shielded the magnet from the outside. The Hexlox Insert is held in place by a very small magnet, but the key doesn't use magnetic force to remove the insert—there's a mechanical connection. We even made a video on the subject: Can a magnet remove Hexlox?

Question: Will the Hexlox Insert fit my bicycle bolts?

Answer: Yes, all bolts on your bike are secured using one of three hex key sizes. Hexlox Inserts are available in these three standard sizes: 4mm, 5mm, and 6mm. To determine the required size, insert an Allen key into the bolt; the size is engraved on the side of the Allen key.

Question: How do the Hexlox Key Code, the Hexlox Key and the Hexlox Insert work together?

Answer: The Hexlox Key and the Hexlox Insert – if they have the same code – form a solid mechanical connection. The shape of the key matches the shape of the insert exactly – but only if they have the same 3-digit code. Different key codes mean that the keys and inserts have slightly different shapes.

That's why we call the Hexlox key a "key," because it essentially works the same way as your front door key. If you take a close look at another Hexlox key with a different code, you'll notice that the tip of the key looks a little different—not much, but it's noticeable.

All Hexlox Keys and Hexlox Inserts in your order will be shipped with the same key code.

Question: Is Hexlox 100% safe?

Answer: There is no lock in the world that is 100% secure– not against a thief who has enough time, motivation, and the right tools. That's the reality when it comes to security – especially with bicycles and bicycle parts.

Most thefts of bicycle parts happen spontaneously. Someone walks by a bike, sees that a saddle or wheel isn't properly secured, and grabs it. Then, of course, there are the well-organized professionals with a real plan—systematic and prepared. All lock manufacturers, including us at Hexlox, develop products specifically designed to help combat these spontaneous opportunistic thieves.

Hexlox is an anti-theft system specifically designed for bicycle components—wheels, seatposts, saddles, and other parts secured with standard Allen screws. Our solution is simple yet effective: a small magnetic insert that blocks access to the screw. Without the appropriate key, it's almost impossible to reach

We always recommend combining Hexlox with a solid frame lock and securing your bike to something solid, like a lamp post or bike rack. Security works in layers—a single solution is never enough.