Product Overview

Our Hex Socket Set Screws, also known as Grub Screws, are the perfect headless fastening solution for securing objects within or against another object. With a precision internal hex drive (Allen drive), these screws provide high torque and a flush finish, making them essential for mechanical assemblies where a protruding screw head is not an option.

As critical headless screws in industrial fastening, our set screws are designed to secure gears, pulleys, sprockets, and other components to shafts without the need for nuts. The Allen head set screws deliver a clean, professional appearance while providing exceptional holding power in confined spaces where traditional bolt heads would interfere with moving parts.

Technical Highlights

Precision Threading: Fully threaded from top to bottom with high-precision tolerances (6g/6h) for a tight and secure fit. Our stainless steel hex socket set screws M3 M4 M5 are manufactured to exacting standards, ensuring consistent thread engagement and reliable performance across every production batch.

Durable Materials: Available in 304/316 Stainless Steel for corrosion resistance or 12.9 Grade Alloy Steel for high-tensile applications. Our black oxide alloy steel grub screws provide maximum strength for demanding mechanical applications, while stainless steel variants offer superior rust protection for outdoor and marine environments.

Flush Installation: The headless design allows the screw to be fully submerged in the threaded hole, saving space and preventing interference with moving parts. This makes our hex socket set screws for pulleys and gears the ideal choice for compact mechanical assemblies where clearance is critical.

Multiple Point Types: We offer Cup Point (for maximum grip on shafts), Flat Point (to avoid damage to the shaft surface), Cone Point (for permanent location and alignment), and Dog Point (for through-hole alignment). Each point type is optimized for specific applications, ensuring the best possible performance for your assembly requirements.

Technical Specifications

Versatile Applications

Machinery: Essential for securing gears, pulleys, and sprockets to shafts. Our hex socket set screws for pulleys and gears provide reliable, high-torque connections that keep power transmission components firmly locked in position. The cup point design digs into the shaft surface, creating a mechanical lock that prevents slipping even under heavy loads.

Hardware & Fixtures: Widely used in door handles, towel bars, faucets, and cabinet hardware. The wholesale headless bolts for industrial maintenance provide a clean, invisible fastening solution for consumer and commercial hardware where aesthetics and functionality are equally important.

Automotive: Applied in internal engine components, steering systems, brake assemblies, and transmission components. Our 12.9 grade alloy steel grub screws withstand the extreme temperatures, vibrations, and loads of automotive applications, providing reliable fastening in critical safety systems.

Robotics & DIY: Perfect for 3D printers, CNC machines, and model making. The stainless steel hex socket set screws M3 M4 M5 are the go-to choice for makers and engineers building precision mechanical assemblies. The small sizes and flush installation make them ideal for compact robotic joints and linear motion systems.

Electronics & Instrumentation: Used for securing components within electronic enclosures, mounting sensors, and assembling precision instruments. The corrosion resistant stainless steel variants ensure long-term reliability in sensitive electronic environments.

Why Partner With Us?

Standard Compliance: All products meet international DIN/ISO/ANSI standards including DIN 916 (cup point), DIN 913 (flat point), DIN 914 (cone point), and DIN 915 (dog point). Our DIN 916 cup point set screws are manufactured to exacting specifications, ensuring full compatibility with international standard components and assemblies.

Large Inventory: Millions of pieces in stock for rapid dispatch. Our extensive inventory covers all standard sizes from M2 to M20 in various materials, point types, and lengths. The wholesale grub screws program ensures competitive pricing and fast delivery for both small and large orders.

Customization: We can produce non-standard lengths, specialized thread pitches, and custom point designs upon request. Our engineering team works directly with OEM customers to develop custom set screw solutions for unique applications, including special materials, coatings, and dimensional requirements.

Quality Assurance: Manufactured under ISO 9001:2015 quality management system with full material traceability. Each batch undergoes rigorous testing including dimensional inspection, hardness testing, and torque verification. Material certificates and test reports available upon request.

Installation / Usage Tips

What is the difference between a set screw and a grub screw? There is no difference – they are the same product. “Set screw” is the term used primarily in North America (ANSI standards), while “grub screw” is the term commonly used in the United Kingdom, Europe, and Australia. Both refer to a headless screw used to secure one object within or against another. Regardless of the name, our hex socket set screws deliver the same reliable performance worldwide.

Proper Torque Application: Always use the correct size Allen key (hex key) for your set screw. Using an incorrectly sized key will strip the hex socket, making the screw impossible to tighten or remove. Apply firm, even pressure when tightening – avoid over-torquing which can break the screw or damage the threads. For critical applications, use a torque wrench to ensure consistent clamping force.

What size Allen key for M6 set screw? The standard Allen key sizes for metric set screws are: M2 = 1.5mm | M2.5 = 2mm | M3 = 2.5mm | M4 = 3mm | M5 = 4mm | M6 = 5mm | M8 = 6mm | M10 = 8mm | M12 = 10mm. Always verify the key size before installation to prevent socket damage.

Point Type Selection: Cup Point (most common) – provides excellent grip on shafts, creates a small indentation for locking. Flat Point – used when the shaft surface must not be damaged, provides a larger contact area. Cone Point – for permanent location, embeds into the shaft material. Dog Point – for alignment through a hole in the shaft, provides precise positioning.

Shaft Preparation: For cup point set screws, a small flat spot (seat) filed or machined on the shaft surface significantly improves grip and prevents the screw from walking under vibration. This is especially important for high-torque and high-vibration applications.

How to Remove a Stripped Hex Set Screw: If the hex socket is stripped, try these methods: 1) Use a larger Allen key with gentle tapping to seat it. 2) Use a screw extractor (easy-out) designed for hex sockets. 3) Create a slot with a Dremel cutting wheel and use a flathead screwdriver. 4) Use needle-nose pliers if any part of the screw head is accessible. 5) As a last resort, carefully drill out the screw and re-tap the hole. Prevention is better – always use the correct key size and avoid over-torquing.

Thread Locking: For applications subject to vibration, apply a small amount of thread-locking compound (Loctite) to the set screw threads before installation. This prevents loosening without making future removal impossible. Medium-strength (blue) thread locker is recommended for most applications.

Custom Application Support: For unique requirements such as special materials, non-standard dimensions, or custom point designs, contact our engineering team for comprehensive design assistance. We provide material selection guidance, torque calculations, and custom manufacturing solutions. Learn more about our manufacturing capabilities.