- Thread size: M3 metric
- Length: 3mm
- Type: Grub screws / Set screws
- Socket type: Internal hex socket
- Design: Headless fasteners
- Quantity per pack: 10 pieces
- Brand: Radio Active
- Part number: I-RMA5250
- Barcode: 5055426743340
- Recommended hex key size: 2mm
- Material: Hardened steel
- Application: General RC models, hobby projects, mechanical fittings, hubs, couplers, collars
- Compatible scales: 1/10, 1/8, 1/7, 1/6 and all other RC scales requiring M3x3 fasteners
Overview
The Radio Active Couple - M3x3 Grubscrews (pk10) represents essential fastening hardware for RC enthusiasts and model engineers across the UK who demand precision and reliability in their builds. These metric M3x3 grub screws are compact set screws designed to secure small components with accuracy, making them invaluable for general RC and modelling maintenance tasks. Whether you're working on RC cars, boats, aircraft, or general hobby projects, having a reliable pack of M3x3 grub screws in your toolbox ensures you can complete repairs and upgrades quickly and professionally.
Grub screws, also known as set screws, are headless fasteners with an internal hex socket that allow them to sit flush within component surfaces. This makes them ideal for securing hubs, couplers, collars, and other small mechanical fittings where a tidy appearance and compact profile are essential. The M3x3 specification—with an M3 metric thread and 3mm length—strikes the perfect balance for most hobby applications, offering sufficient thread engagement without excessive bulk. This pack contains ten individual screws, providing multiple fastening solutions from a single purchase.
For RC hobbyists in the UK maintaining everything from brushless RC cars to electric and nitro-powered models, these grub screws prove indispensable for routine upkeep and component replacement. Model engineers working on scale aircraft, boats, and mechanical assemblies will appreciate the precision engineering of metric hardware. Keep a pack of M3x3 grub screws in your workshop and you'll always have the right fastener available when modifications or repairs are needed.
Key Features
- Metric M3 Thread — The M3 metric specification ensures compatibility with standard metric hardware and components commonly used in RC models and hobby projects, providing reliable compatibility with your existing builds and replacement parts.
- 3mm Length — The compact 3mm length makes these grub screws perfect for securing small components and mechanical fittings where space is limited, such as propeller hubs, coupling collars, and component retention points on model vehicles and aircraft.
- Set Screw Design with Hex Socket — The internal hex socket allows for secure tightening using a standard hex key, and the headless design means the screw sits completely flush within the component surface, creating a clean, professional appearance and eliminating protruding screw heads that could catch or cause damage.
- Pack of 10 — With ten screws included, you have multiple fasteners available for different projects or as spares, ensuring you always have a replacement available for routine maintenance without needing to purchase additional packs.
- General Purpose Application — These grub screws suit a wide range of RC models and general hobby builds, from RC buggy and truck maintenance to aircraft assembly and model engineering projects, making them a versatile addition to any hobbyist's spare parts collection.
- Precision Engineering — Radio Active hardware is manufactured to exacting standards, ensuring consistent quality and reliable performance across all ten screws in the pack.
Technical Performance
The Radio Active M3x3 Grubscrews are manufactured to professional standards using hardened steel, ensuring durability and reliable long-term performance in demanding RC and model engineering applications. The metric M3 thread provides excellent thread engagement when securing components, whilst the 3mm length ensures the screw can penetrate fully into component materials without protruding excessively. The internal hex socket design allows precise tightening without risk of stripping the fastener head, a common problem with slotted or Phillips-head alternatives. These grub screws are suitable for securing small mechanical fittings across a broad range of scales and applications—from 1/10 scale RC cars and 1/8 scale buggies to larger aircraft and marine models where metric fastening hardware is specified. The headless design eliminates sharp protrusions and creates a flush, professional finish within assembled components. Whether you're working on routine maintenance of your RC collection, securing replacement hubs and couplers, or undertaking detailed model engineering projects, these fasteners deliver the precision and reliability expected from Radio Active branded hardware.
What's in the Box
- 10x M3x3 Grub Screws (set screws with internal hex socket)
Frequently Asked Questions
- What are grub screws used for in RC models? — Grub screws are headless fasteners with an internal hex socket used to secure small components such as propeller hubs, motor pinions, coupling collars, and other mechanical fittings. In RC cars, boats, and aircraft, they provide a clean, flush fastening solution where protruding screw heads would interfere with moving parts or compromise the model's appearance. The M3x3 size is ideal for securing small components across a wide range of RC scales and hobby applications.
- Will these M3x3 grub screws fit my RC model? — The M3x3 specification will suit any RC model, coupling, hub, or mechanical fitting that requires an M3 metric thread with approximately 3mm engagement length. Refer to your model's instruction manual or parts diagram to confirm whether M3x3 is the correct specification for your specific component. Common applications include motor pinion retention, propeller hub security, and coupling collar fastening on RC cars, trucks, buggies, and aircraft.
- What type of hex key do I need to tighten these screws? — M3x3 grub screws typically require a 2mm hex key (Allen key) for tightening. Ensure you use the correct size to avoid stripping the internal socket. Most RC enthusiasts carry a set of metric hex keys as standard workshop tools.
- Are these grub screws suitable for brushless RC cars? — Yes, these M3x3 grub screws are suitable for use on brushless RC cars, brushed RC models, nitro-powered vehicles, and electric aircraft. They provide reliable component retention across all RC scales and power systems where metric M3 fastening is specified.
- How many projects can I complete with ten grub screws? — The pack of ten provides multiple fastening solutions across different projects or serves as spare inventory for your workshop. Depending on your application, you might use one or two screws per component, so this pack is suitable for securing multiple components or providing spares for future maintenance and upgrades.
- What is the difference between a grub screw and a standard machine screw? — Grub screws are headless set screws with an internal hex socket that sit completely flush within component surfaces, creating a clean, professional appearance. Standard machine screws have external heads that protrude from the surface. For RC applications where space is tight and appearance matters, grub screws are the superior choice.
Why Buy from RC Model Shop?
RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the Couple - M3x3 Grubscrews (pk10) today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.
We want to make sure your delivery goes smoothly, so here are some important details about our service:
- For orders above £120, we offer delivery to most mainland UK addresses. For orders under £120, we can still deliver to Northern Ireland and the outlying isles, as long as the item can be sent by Royal Mail, weighs less than 30kg, and fits within 61cm × 46cm × 46cm. Some highland and remote areas may carry an extra delivery charge as couriers often apply surcharges in these locations. If you live in one of these areas, feel free to contact us before ordering so we can confirm the delivery options and costs for you.
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