Allen screws 4/40

4/40 Thunderslot Allen Screws: precise fastening for wheels and crown gears

In the preparation of a slot car, the details that seem minor are often the ones that make the difference between a solid setup and a failure during the race. The 4/40 Allen Screws from Thunderslot (ref. TH-SC440HEX) embody this philosophy: stainless steel parts, with a 4/40 metric, designed for the secure tightening of wheels and crown gears on the brand's chassis.

Function and performance

The 4/40 thread is a widely used standard in the world of competitive slot racing. Its fine thread pitch allows for controlled tightening without the risk of over-tightening, which is particularly useful for parts made of softer materials such as some plastic wheels or nylon crown gears. Stainless steel provides resistance to corrosion and maintains a stable torque even after numerous assemblies and disassemblies, which is common in workshop tasks.

Compatibility

These screws are intended for use with Thunderslot components that employ this type of thread, primarily wheels and crown gears from the brand's own catalogue. If you plan to use them with parts from other brands, please verify that the diameter and thread pitch match the 4/40 standard.

Assembly and preparation

To tighten these screws, an Allen key of the appropriate size for the hexagonal head is required. We recommend always using calibrated tools and applying gradual and even pressure to avoid deforming the housing. If you will be frequently assembling and disassembling the crown or wheels during setup sessions, it is advisable to periodically check the condition of the thread to ensure that the grip remains optimal.

Common mistakes

• Over-tightening on wheels or crown gears made of soft materials, which can damage the threaded housing.
• Using an incorrectly sized Allen key, which can round off the hexagonal head and render the screw unusable.
• Not verifying the compatibility of the 4/40 thread before mounting on parts from other brands.

Frequently asked questions

What does the designation 4/40 mean?

It is an American Unified Thread Standard (UNC). The "4" indicates the nominal diameter of the screw and the "40" the number of threads per inch. It is a common metric in competitive slot components of American origin and in many accessories from European brands that have adopted it.

Are these screws suitable only for Thunderslot cars?

They are designed for Thunderslot components that use the 4/40 thread, but can be used on any part — from any brand — that shares that same thread standard. Always check compatibility before mounting them.

Why stainless steel and not carbon steel?

Stainless steel better withstands moisture and cleaning products commonly used in the maintenance of slot material. Additionally, it maintains its mechanical properties over time, making it ideal for parts subjected to repeated assemblies.

How many screws are included in the pack?

The available information does not specify the exact number of units per pack. We recommend checking directly on the product page or contacting our team.

Thunderslot TH-SC440HEX Allen screws 4/40 stainless steel for slot car wheels and crown gears. A precise and durable fastening solution for club racers and slot car enthusiasts looking for reliable setup components. Compatible with all parts using the 4/40 thread standard.