The Benefits and Applications of Thumb Screws

Thumb Screws are used across a multitude of industries, learn why!

The appeal of thumb screws lie in their simple but effective design. With just a few turns, they allow for screws to be, tightened, loosened, fastened, and removed. They are especially useful in smaller spaces as they do not require clearance for use of a screwdriver. Using the torque of your hand also reduces the risk of over-tightening.

One popular use for thumb screws is with safety covers for electronic devices and access panels on industrial machinery. Unlike generic screws, which can become brittle and broken when being adjusted with tools, thumb screws remain sturdy and easy to remove.

Types of thumb screws

There are two types of thumb screws: Type A and Type B.

Type A thumb screws, which may also be referred to as Type S, feature a shoulder that provides a bearing surface to allow the screw to be tightened against a surface.

These screws are measured from under the shoulder of the screw to the tip.

Type B thumb screws are also known as Type P. They are without shoulder are often used as compression fasteners, like a grub screw.

Whether type A or type B, thumb screws can be sourced in several materials, shapes, and sizes. At Elesa we pride ourselves on providing the wide range you deserve, so in our catalogue you will find the following designs and more:
• Three-arm knobs for easy manoeuvrability
• Lobe knobs with a solid section for easy cleaning
• Lobe knobs with locking thrust pad for forceful securing
• Fluted knobs for tightening with a screwdriver
• Star knobs for an extra secure grip
• Safety lobe knobs: to ensure operation by authorised personnel only

Metal thumb screws
Thumb screws made from metal such as stainless steel, cast iron, and aluminium can be used in many applications. Metal thumb screws can be regarded as the most reliable and durable as they provide excellent positional precision.

Metal screws are corrosion-resistant, meaning they will remain looking flawless over time. Easy to clean, they are a good choice for use in environments that require a high level of hygiene—such as catering and medicine.

Our stainless steel and cast-iron knobs are available in various styles and finished to suit your needs.

Technopolymer thumb screws

For a lightweight component that doesn’t compromise on quality, our plastic thumb screws make the perfect option.

Available in a range of shapes and colours, our plastic thumb screws are made from superior materials of duroplast and technopolymer. These screws are an effective non-conductive solution with all the efficiency of metal screws.

How to find the thumb screws you need

In the Elesa catalogue, you will find a whole host of knurled screws to suit your requirements. Once you have identified your preferred style, you will need to ensure you choose the right size.
In the UK, the thread gauge and diameter of thumb screws are measured using metric units.

There are several common sizes that fit the threaded holes on a wide range of everyday devices and panels in the UK. These include:

• M6 thumb screws
• M4 knurled thumb screws
• M8 thumb screws
• M12 thumb screws

The sizing of M6, M4, M8, and M12, for example, refers to the diameter of the screw shaft in millimetres. The thread measurements tell us the length of the gap between the thread ridges. In the case of a M6 thumb screw with a thread size of 0.70mm, we can tell that the screw has a 6mm shaft diameter with a 0.70mm gap between the threads.

In our catalogue you will find threaded screw sizes ranging from M3 to M16 and external diameters from 25mm to 140mm. Our knurled screws are available in the following assembly types for your convenience:

• Blind hole
• Threaded screw
• Pass-through hole
• Not drilled

For the full range of thumb screws, knurled screws, and accessories such as toggle nuts, visit the Elesa catalogue today.