⚙️ How They Work
When you close the window, the smooth cylinder drops behind a simple metal plate (keep) screwed to the frame. The contact is merely a resting position - no hook, no interlock.
Mushroom Cams vs Plain Rollers: How burglars "unhook" old windows
When we think of a burglary, our mind goes to smashed glass and movie scenes. Reality is silent and far more technical. Statistics show most burglars avoid breaking glass - the noise is enormous and the injury risk is high.
Their favourite method? Pry-bar attack. The burglar inserts a screwdriver between the sash and frame, and a tiny piece of hardware decides whether he succeeds or fails: the roller (or the "mushroom cam").
1. The Achilles' Heel: Plain Cylindrical Rollers
If you open an old (or very cheap) window, you will see small metal cylinders along the side hardware strip that move up and down when you turn the handle. These are plain rollers.
🔓 Defeated in 10 Seconds
The burglar inserts a pry bar between sash and frame, applies horizontal pressure. The aluminium flexes 1–2 cm, the smooth cylinder slides out of the keep. The door opens without anything breaking.
⚠️ Warning Sign
If your rollers are completely smooth and cylindrical, like small barrels, then your home's security relies solely on psychological deterrence - not mechanical resistance.
2. The Ultimate Defence: Mushroom Cams
Engineers redesigned the small cylinder: instead of being smooth, they gave it a wide "head" on top. The shape now resembles a mushroom (or the letter "T").
🔒 Hooked Locking
The mushroom "head" enters a special security keep - a metal "nest" with a lip. It forms a mechanical hook that cannot be defeated by horizontal force.
💪 Why the Pry Bar Fails
The pry bar presses to separate the sash → but the mushroom is hooked behind the lip. The only way in is to tear the steel keep from the frame or snap the aluminium itself - enormous noise.
🎯 The Critical Detail
The mushroom alone is not enough. It must be paired with a purpose-made security keep. If someone says "it has mushroom cams" but the keeps are plain plates, the protection is false.
3. How It Works in Practice: The Security Keep
Imagine interlocking your fingers like hooks (hooked fingers). No matter how hard you pull apart, they won't separate. This is exactly the principle behind the mushroom-cam–keep connection.
🏗️ Construction
The security keep is not a flat plate - it has an internal recess (nest) with a lip. Made from steel or reinforced zinc alloy, screwed into the frame profile.
🔐 RC2 Certification
The combination of mushroom cams + security keeps is an essential prerequisite for the RC2 and RC3 burglary-resistance certifications (EN 1627).
4. Do the Home Test!
Want to find out what security level your current windows have? Perform this 30-second visual check - no tools, no technician needed.
1️⃣ Open the Sash
Open an opening sash (balcony door or window) fully. Look at the metal hardware strip along the side.
2️⃣ Find the Locking Points
Locate the small metal fittings protruding along the strip - these are the locking points.
3️⃣ The Verdict
Completely smooth and cylindrical like small barrels? → Plain rollers (low security). A distinct, wider "cap" on top? → Mushroom cams - congratulations!
💡 Tip: Security is not determined by aluminium thickness, but by smart engineering. "Mushroom cams" is the first term you should look for in the technical specifications.
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Burglary Resistance Classes (RC1 to RC6) Multi-Point Locking Mechanism: Ultimate Window Security Add-on Locks for Sliding Aluminium Windows Window Handles & Security: Secustik Technology & Locks
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