Types of Grub Screws: A Complete Guide.

Grub Screws, also known as Set Screws are small, headless fasteners designed to secure one part to another, usually within mechanical and electrical assemblies. Unlike traditional screws, they feature a simple cylindrical body and a drive recess, with no visible head. This "headless" design allows them to sit flush with the working material, ensuring a clean and secure connection without any protruding parts or countersinking requirements.

This guide covers Grub Screw types, materials and thread options. As well as this, we feature handy reference tables including all available grub screw sizes and finishes, helping you find the right fastener when you need it.

Contents: 

• How do Grub Screws work?

• Choosing the right set screw for your material.  

• The different types of Grub Screws available.

• FAQs

Grub Screws, Quick Reference Tables: 

How Do Grub Screws Work and What Are They Used For?

How Grub Screws Work.

Grub screws are designed to secure components together by threading into the surrounding component material, usually without the need for a nut in the same way a traditional screw or bolt would. Where they differ from normal screws is that they are typically tightened using an internal drive, such as a Hex/Allen key, Slotted drive or Torx driver.

Unlike a standard screw, a grub screw’s effectiveness also comes from its tip geometry. The point/tip style acts as the working face. It either bites, locates, or cushions against the mating part, depending on the type, converting torque into clamping or indexing force exactly where it is required. Traditional screws rely on the underside of a protruding head to press a fixture together; a grub screw transfers that load through its specialised tip, letting it clamp, align or detent entirely below the surface line.

The headless design allows the set screw to sit flush with the surface, making it ideal for applications where a protruding screw head is impractical. The threaded body of the grub screw helps to create a strong, secure connection, providing stability without taking up extra space and creating snagging or interference points with a protruding head.

Grub Screw Anatomy.

To fully appreciate how grub screws provide secure fastening, it’s essential to understand their key components. A typical grub screw consists of four primary parts – the Drive, Shank, Thread and Point. Each element plays a crucial role in the screw’s function, ensuring it holds components in place without the need for a protruding head.

• Drive: The recess in the top of the screw that allows it to be tightened or loosened using a specific tool and drive type.

• Shank: Most Grub Screws feature fully threaded bodies unless specified and as headless fasteners, do not have a typical shank unless otherwise stated.

• Thread: The spiral ridge that runs along the length of the screw, allowing it to interact with other threaded components securely. Different screws feature different thread pitch angles each with their own unique properties.

• Point: The tip of the screw that comes into contact with the material. Different point styles like cone or cup offer various types of grip/alignment depending on the application; we cover this further down in the guide.

Understanding these key features will help you make informed decisions when selecting the right grub screw for your project.

You can learn more about these specific features in our How to Measure a Grub Screw Guide.

What Are Grub Screws Used For?

Grub screws are commonly used in mechanical and engineering applications requiring specific interference and alignment fits between components. 

They are often employed to secure components like axles, gears and shafts in place, preventing them from slipping or loosening over time; Socket Head Brass-Tipped Grub Screws provide this by applying pressure without marring the shaft's surface. Grub screws are also used in furniture manufacturing for joining parts securely without visible fasteners. Additionally, small grub screws can be found in electronics and automotive industries, securing small parts in confined spaces. Their versatility makes them a robust solution for situations requiring secure, flush fastening.

Choosing the Right Grub Screw for Your Material.

Grub screws solve fastening problems that ordinary "headed" screws can’t touch. Because they sit flush, they avoid snagging in confined spaces, allow shafts to pass closely through housings and let cosmetic surfaces remain uninterrupted.

Yet, this headless format presents its own engineering challenges: it must generate clamping force without a large bearing face, maintain alignment with no visible reference, resist vibration even though the screw is often small, and avoid scarring sensitive surfaces that must still slide or rotate.
Tip geometry is how these fasteners overcome those obstacles.

We’ll discuss the eight tip styles below: each trade-off bite depth, contact area, self-locking behaviour and serviceability. By matching those characteristics to the five functional concerns that follow, you’ll reach the right choice quickly; size, thread and finish can then be selected from the tables later in the guide.

Maximum Holding Power.

When slip is unacceptable and torque or shock loads are high.

 

Surface Protection.

Clamp firmly while leaving finishes intact.

Precise Alignment.

Keep components indexed or repeatably positioned.

Vibration Resistance.

Prevent back-out in assemblies that buzz, hammer or cycle.

Ease of Adjustment.

Frequent tweaks with minimal wear or galling.

What About Set Screws and Corrosion? 

When choosing set screws for your project, corrosion resistance plays an important role, especially when fasteners are exposed to harsh environments. Just like other types of screws, selecting a grub screw that offers appropriate corrosion resistance ensures long-lasting performance and prevents failure caused by environmental factors.
Below, we’ll explore key considerations in corrosion resistance specific to grub screws, including the difference between indoor and outdoor use, options for specialist corrosion-resistant materials and custom coatings or thread lockers.

Indoor/Outdoor Corrosion & Grub Screws.

When selecting grub screws for indoor use, corrosion resistance is generally less of a concern, as these fasteners are less likely to be exposed to moisture or aggressive elements. Standard materials like steel or brass are typically sufficient for indoor applications where the screws won’t face environmental stress. However, even indoor environments can have varying humidity levels, so it’s still wise to consider stainless steel or other corrosion-resistant materials for areas prone to moisture.

For outdoor applications, particularly in humid, salty, or coastal environments, corrosion resistance becomes crucial. Stainless Steel grub screws are the ideal choice for these conditions, offering superior resistance to rust and corrosion. Titanium grub screws are also a strong option for extreme environments, such as marine or industrial settings, due to their exceptional durability and resistance to corrosion. Choosing the right corrosion-resistant material ensures that the grub screws maintain their integrity and strength over time, even when exposed to challenging conditions.

Specialist Corrosion Resistance Grub Screws.

For applications in particularly corrosive environments, there are specialised grub screw materials that provide enhanced resistance to rust and deterioration.
A4 stainless steel is often recommended for applications exposed to saltwater or harsh chemicals, offering greater resistance compared to standard A2 stainless steel.

In some cases, brass-tipped grub screws or nylon-tipped grub screws may also be used for their natural corrosion resistance, especially in electrical or low-stress applications. These screws provide a softer, non-corrosive material at the tip, protecting the base material and preventing surface damage. 

In specialised cases, consider PEEK or POM (Acetal) as a solid alternative to steels and other metals; these advanced plastic grub screws offer a non-conductive, chemically inert solution for fastening. 
Choosing the right material for these applications ensures that your grub screws remain functional and free from corrosion, even in hostile environments.

Custom Coatings & Thread Lockers.

In addition to selecting the right material, custom coatings and thread lockers can be used to enhance corrosion resistance and increase the longevity of grub screws. Coatings such as zinc plating or our optional AccuBlack finish offer an extra layer of protection against corrosion, especially in environments where moisture or chemicals may be a concern. These coatings also help reduce friction during installation, making the screw easier to tighten without causing damage to the material.

For added protection against loosening due to vibrations or environmental factors, our thread lockers can be pre-applied to some styles of grub screws. These compounds create a secure bond that prevents the screw from loosening over time, providing an additional layer of defence against corrosion. This is particularly useful for screws exposed to fluctuating temperatures or frequent movement, where corrosion and loosening could lead to failure.

The Different Types of Grub Screw Available. 

This section of our guide is designed to help you select the right Grub Screw for the job with minimal fuss. 

Here we list the material suitability in a simple system alongside all the material, functional and optional specifications so you can be assured you select the right fastener every time with a clear understanding of its properties.  

 

 

Cup Point Grub Screw Explored.

Cup point grub screws feature a rounded, recessed tip that provides a broad surface area for contact with the material. This design helps to distribute pressure evenly, making it perfect for securing parts without causing significant damage to softer materials. The rounded tip offers a strong grip and is less likely to slip compared to sharper-pointed screws in similar applications.

 

SHOP CUP POINT GRUB SCREWS.

 

 

 

 

 

 

Cup Point Grub Screw Material Suitability Table:

Materials and Sizes of Cup Point Grub Screw Available:

Cup Point Grub/Set Screws Tips:

• Ideal for applications requiring broad, even pressure distribution.

• Works well in low-stress connections where a secure, flush fit is needed.

• Best used in environments where a strong grip is required without causing surface damage.

• A great choice when a permanent hold is not required but a secure connection is needed.

 

 

Flat Point Grub Screw Explored.

Flat point grub screws feature a flat tip that applies even pressure across the surface of the working material. It’s perfect for applications where you need minimal penetration and want to avoid damaging the surface. This screw style is great for applications requiring secure fastening without excessive force and is commonly used in low-stress applications.

 

SHOP FLAT-POINT GRUB SCREWS.

 

 

Flat Point Grub Screw Material Suitability Table:

Materials and Sizes of Flat Point Grub Screw Available:

Flat Point Grub/Set Screws Tips:

• Ideal for applications requiring even pressure distribution without deep penetration.

• Best used for securing components to flat surfaces.

• Works well in low-stress environments where a flush fit is desired.

• Ideal for use when surface protection is a concern, as it prevents deeper material penetration.

 

 

Cone Point Grub Screw Explored.

Cone point grub screws have a sharp, tapered tip that allows it to dig into materials for a secure, firm hold. It is well-suited for softer materials like wood, plastic and soft metals, where a deep grip is necessary. This screw style is often used when a high-precision, strong connection is required, such as in high-torque mechanical assemblies.

SHOP CONE-POINT GRUB SCREWS.

 

 

 

 

 

 

Cone Point Grub Screw Material Suitability Table:

 

Materials and Sizes of Cone Point Grub Screw Available:

Cone Point Grub/Set Screws Tips:

• Ideal for applications requiring strong, high-precision holds and deep material penetration.

• Works well in high-torque applications where resistance to loosening is important.

• Use for tasks requiring a deeper engagement with the material to resist movement.

• Choose a finer thread pitch for harder materials, ensuring maximum grip without excess force.

 

 

Dog Point Grub Screw Explored.

Dog point grub screws feature a cylindrical tip that fits precisely into a corresponding hole, providing stability and preventing lateral movement. This screw style is perfect for mechanical applications where alignment is essential, such as in shafts or gears. The cylindrical point ensures better control and prevents shifting after installation, making it ideal for assemblies requiring precise positioning.

 

SHOP DOG-POINT GRUB SCREWS.

 

 

 

 

Dog Point Grub Screw Material Suitability Table:

Materials and Sizes of Dog Point Grub Screw Available:

Dog Point Grub/Set Screws Tips:

• Ideal for mechanical applications requiring precise alignment of components.

• Best used in applications where the screw must resist lateral movement after installation.

• Ensure that the corresponding hole is accurately drilled to fit the cylindrical tip.

• Choose a coarser thread for thicker materials to provide a stronger hold.

 

Knurled Cup Point Grub Screws Explored.

Knurled cup point grub screws combine the broad, stable grip of a cup point with knurling to improve resistance to loosening. This knurling is especially useful in applications subject to vibrations, as it helps prevent the screw from coming loose over time. This makes the knurled cup point ideal for automotive, machinery and industrial uses where vibration is a design concern.

SHOP KNURLED CUP-POINT
GRUB SCREWS.

 

 

 

 

Knurled Cup Point Grub Screw Material Suitability Table:

Materials and Sizes of Knurled Cup Point Grub Screws Available:

Knurled Cup Point Grub Screws Tips:

• Perfect for applications exposed to vibrations or high-torque conditions.

• The knurled design enhances grip, helping prevent loosening over time.

• Choose an appropriate thread pitch to balance security and ease of installation.

• Ideal for applications requiring a stronger grip but without permanent installation.

 

 

Brass Tipped Set Screw Explored.

Brass-tipped set screws have a brass tip designed to prevent damage to softer materials, such as plastics, soft metals, or delicate components. The brass tip helps to protect the material’s surface while providing a secure hold. This screw is often used in electrical or low-stress applications where protection against corrosion and wear is essential.

SHOP BRASS-TIPPED GRUB
SCREWS.

 

 

 

 

Brass Tipped Set Screws Material Suitability Table:

Materials and Sizes of Brass Tipped Set Screws Available:

Brass Tipped Set Screws Tips:

• Ideal for securing delicate components where surface protection is necessary.

• The brass tip reduces the risk of material damage while maintaining a strong connection.

• Use in low-stress applications where corrosion resistance and material protection are key.

• Best for light-duty applications where corrosion resistance is important.

 

 

Nylon Tipped Grub Screw Explored.

Nylon grub screws use a soft nylon tip to provide a cushioning effect that protects sensitive surfaces from damage. This screw is perfect for applications that require both a secure grip and surface protection, such as in delicate plastic or painted components. The nylon tip also helps reduce friction and wear over time, making it ideal for vibration-prone environments.

 Shop Nylon-Tipped Grub
Screws.

 

 

 

 

Nylon Tipped Set Screws Material Suitability Table:

Materials and Sizes of Nylon Tipped Set Screws Available:

Nylon Tipped Set Screws Tips:

• Ideal for applications requiring surface protection while maintaining a secure hold.

• The nylon tip provides cushioning and reduces friction, making it great for sensitive materials.

• Best used in environments where reducing wear and tear is important.

• Works well for applications exposed to vibrations, as the nylon helps dampen movement.

 

Spring-Loaded Ball Grub Screws Explored.

Spring-loaded ball grub screws feature a small, spring-loaded ball at the tip of the screw; this is used to apply consistent pressure on the material being fastened. This design allows the screw to create a secure and adjustable hold, often used in applications where fine adjustments or continuous pressure are required. The spring-loaded ball helps prevent the screw from loosening over time, offering enhanced performance in dynamic or high-vibration environments.

SHOP SPRING-LOADED BALL
GRUBSCREWS.

 

 

 

Spring Loaded Ball Grub Screws Material Suitability Table:

Materials and Sizes of Spring-Loaded Ball Grub Screws Available:

Spring Loaded Ball Grub Screws Tips:

• Ideal for applications where fine adjustments or continuous pressure are required.

• Provides a secure, adjustable hold in both light and heavy-duty applications.

• Perfect for use in environments where vibration could cause standard screws to loosen.

• Commonly used in machinery, automotive, and equipment requiring constant pressure or movement.

FAQs

Q: What is the difference between a grub screw and a set screw?

A grub screw and a set screw are both headless fasteners used to secure components. The main difference is that grub screws are fully threaded, while set screws may have a partially threaded body. Grub screws are typically used when a flush fit is needed, while set screws may have a small protruding head.

Q: What are the most common applications for grub screws?

Grub screws are used to secure parts like pulleys and shafts in place without protruding above the material's surface. They are common in machinery, automotive applications and furniture assembly, with Torx grub screws and Allen key grub screws offering secure installation in high-torque environments.

Q: Can I use a brass grub screw in outdoor applications?

Yes, Brass Tipped Grub Screws can be used in outdoor applications thanks to the non-ferrous nature of the brass tip, and optional treatments like thread-locker and corrosion resistance materials.

Q: How do I prevent grub screws from loosening over time?

To prevent grub screws from loosening, opt for Torx grub screws or Allen key grub screws for better torque resistance. Applying a thread locker or using nylon-tipped grub screws can also help keep them secure, particularly in vibration-prone environments.

Q: What tools do I need to install a grub screw?

You’ll need a driver that matches the screw’s drive type, such as an Allen key for Allen key grub screws or a Torx driver for Torx head grub screws. A torque wrench can help ensure proper tightening without over-tightening if you have access to one.