Everything you need to know about conical head grub screws (Allen screws) for door handles

A detailed article that explains what the "grub screw" and the "Allen screw" are when it comes to fitting door handles.

When installing door handles, it is essential to use the correct components, such as conical head grub screws, also known as Allen screws. These screws play a crucial role in securing door handles by ensuring a strong and durable grip. But what exactly is a conical head grub screw (Allen screw)? Through this article, we will explore in detail what a grub screw is, how it works, and give you some expert tips for a successful installation of your door handles.

1. Conical Head Allen Screw (Grub Screw)

Grub screws are specially designed to firmly hold door handles on a square spindle passing through the door. These grub screws feature a conical point and an Allen key socket. When you tighten the screw using a rotational movement, the square spindle expands, thus immobilising the handle securely.

These grub screws are made of brass, a robust material, guaranteeing their longevity. The "head" of the screw can also be made of galvanised steel.

An important feature of these grub screws is their conical head. This design allows for precise and stable fixing of door handles, preventing any unwanted movement. Some grub screws also have a countersunk head or round head, offering different options for aesthetics and function.

It is common to find grub screws in different sizes, such as M6 and M3, to suit various applications. The choice of size depends on the type of door handle you are installing.

The standard mounting kit for a door handle generally contains two types of screws:

• One M6 Allen screw per handle, used to fix the handle lever onto a split square spindle.
• A small M2/M3 Allen screw, designed to fix the handle plate onto the metal adapter.

Expert Advice: When using grub screws, make sure to tighten them firmly to avoid any play in the door handle. However, do not overtighten, as this could damage the square spindle or the handle itself.

Furthermore, if you are installing a door handle on a wooden surface, it is recommended to use appropriate wood screws for robust fixing. These screws are specially designed for wood and guarantee a strong grip.

Here is a comparison table of Allen grub screw dimensions, including different sizes such as Allen M3, Allen M4, Allen M5, and Allen M6.

The grub screw is sometimes called "binding screw", "fixing screw", "fastening screw", or even "door handle screw". An example of installing a handle with Allen grub screws is illustrated below.

Here is the dimensions table:

2. How to install an Allen grub screw in a square spindle

The correct installation of an Allen screw is essential to ensure that the door handle remains securely in place. The screw must be inserted into the square spindle in such a way that it expands inside the handle. This creates an Archimedean screw or worm screw effect, which effectively locks the handle onto the door.

Using an Allen key is recommended to ensure precise tightening of the screw in the square spindle. Make sure the screw is properly aligned before starting to tighten. Once tightened, the handle should be firmly fixed without any play movement.

By putting these expert tips into practice and making the right choice among conical head grub screws (Allen screws) and the necessary door spare parts, you ensure a trouble-free installation and maintain the stability and security of your door handles in the long term.

So, don't wait any longer to start your fitting works! Our Millapoignées shop offers you a magnificent catalogue of handles, parts and accessories.