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Socket head screws, also known as Allen screws, are indispensable fasteners for a wide range of applications, from furniture assembly to machinery repair. Their hexagonal socket drive allows for high torque application and a clean, flush finish. Selecting the correct type and size ensures secure connections and prevents damage to both the screw and the equipment.
【Perfect for DIY Projects】 This M3 screw assortment kit are ideal for hobbyists working with 3D printing, electronics, RC models, DIY repairs, chair replacement and CNC machinery, offering precision for intricate designs.
【Standardized Metric Sizes】 -The M3-0.5 hex socket head cap screws set come with 8 commonly used lengths—M3 x 6mm, 8mm, 10mm, 12mm, 16mm,20mm,25mm,30mm—ideal for routine installations and repairs. They meet standard metric specs, the average error...
【Premium 12.9 Grade Alloy Steel】- This M3 bolts, nuts and washers assorted kit are crafted from high-strength 12.9 grade alloy steel, ensuring exceptional durability and load-bearing capacity. High-strength steel resists wear, corrosion, and heavy...
【Oil-Free & Rust-Proof】 -Black zinc plating means no greasy mess—keep hands and projects clean. Superior rust resistance ensuring long life.This 3mm black allen screw set perfect for any indoor/light outdoor use.
【4 Sizes Metric Screw Set】This 1220pcs screws kit includes M3, M4, M5,M6 sizes with precise thread diameters (3mm/4mm/5mm/6mm) and Lenths of the bolts M3-0.5x6mm/8mm/10mm/12mm, M4-0.7x8mm/10mm/16mm/20mm, M5-0.8x10mm/16mm/20mm/30mm...
【Perfect for DIY Projects】 This hex socket head screw assorted kit are ideal for hobbyists working with 3D printing, electronics, RC models, DIY repairs, chair replacement and CNC machinery, offering precision for intricate designs.
【304 Stainless Steel Material 】 This metric cap head bolts,nuts and washers assortment kit are made of high-quality 304 stainless steel, which resist corrosion and rust, with smooth threads and high hardness for secure fastening, heavy-load capacity...
【Organized Storage Box 】- The M3 M4 M5 M6 allen head screws set comes in a compartmentalized case with clear labels for quick access to bolts, washers, and nuts. Keeps your workspace tidy and speeds up project progress, making every job smoother.
【4 Sizes Metric Screw Set】This 1760pcs screws kit includes M2, M3, M4, M5 sizes with precise thread diameters (2mm/3mm/4mm/5mm) and Lenths of the bolts: M2x6mm/8mm/12mm/16mm, M3x6mm/8mm/12mm/16mm, M4x8mm/12mm/16mm/20mm, M5x8mm/12mm/16mm/20mm...
【Perfect for DIY Projects】 This hex socket head screw assorted kit are ideal for hobbyists working with 3D printing, electronics, RC models, DIY repairs, chair replacement and CNC machinery, offering precision for intricate designs.
【Premium 12.9 Grade Alloy Steel】- This machine screw assortment kit are crafted from high-strength 12.9 grade alloy steel, ensuring exceptional durability and load-bearing capacity. High-strength steel resists wear, corrosion, and heavy loads, ideal...
【Organized Storage Box 】- The M2 M3 M4 M5 allen head screws set comes in a compartmentalized case with clear labels for quick access to bolts, washers, and nuts. Keeps your workspace tidy and speeds up project progress, making every job smoother.
They are coarse thread.Screws Thread Diameter: #2,Thread Pitch: 56 Per Inch;#4,Thread Pitch: 40 Per Inch; #6,Thread Pitch: 32 Per Inch.#8,Thread Pitch: 32 Per InchThread ;#10,Thread Pitch: 24 Per Inch; 1/4",Thread Pitch: 20 Per Inch;5/16",Thread Pitch...
They are Made of 304 stainless steel;304 stainless steel have good chemical resistance and may be mildly magnetic
The assortments contain the following sizes:#2-56x3/16"(20PCS);#2-56x5/16"(20PCS);#2-56x1/2"(20PCS);#4-40x5/16"(20PCS);#4-40x1/2"(20PCS);#6-32x3/8"(15PCS);#6-32x5/8"(15PCS...
Full thread;Length is measured from under the head;Thread Direction: Right Hand
【4 Sizes Metric Screw Assortment Kit】This 2640pcs screws set includes M2-0.4, M3-0.5, M4-0.7, M5-0.8 sizes with precise thread diameters (2mm/3mm/4mm/5mm). Lenths of the thread M2x4mm/8mm/12mm/16mm. M3x4mm/8mm/12mm/16mm. M4x6mm/8mm/12mm/16mm...
【High quality】– Made of durable 10.9 grade alloy steel metric bolts, nuts and washers assorted kit with oil-free black galvanizing for corrosion resistance. Smooth, burr-free surface with precise threading ensures secure fastening. Weatherproof...
【Organized & Portable】The hex socket button head bolt assortment sets are neatly packed in a sturdy plastic storage box, ensuring easy organization and quick access. The metric machine assortment kit includes M2 M3 M4 M5 sizes for convenient...
【Wide Applications】Keep a set of commonly used small screw hardware kit at hand. Whether you are working on DIY projects, small projects repair, or professional construction, it can meet your needs at any time, making your work more convenient and...
【Product Details】- This M5 screw assortment kit comes with a total of 272 pieces, includes 72pcs hex socket head bolts,40pcs hex nuts, 80pcs flat washers, 80pcs spring washers, and a mini wrench.The m5 metric socket head cap screw kit feature...
【High Quality】– Made of durable 12.9 alloy steel 5mm black hardware kit with oil-free black galvanizing for corrosion resistance. Smooth, burr-free surface with precise threading ensures secure fastening. Good rust resistance for indoor/light...
【Wide Applications】This M5 hex socket head bolts assorted kit is perfect for all sorts of building and repair projects. Whether you’re into 3D printing, working on RC cars, fixing small electronics, or tackling DIY jobs—these screws have you...
【Organized Storage Box 】- The M5 machine screw set comes in a durable, compartmentalized case with clear size labels—so you can spot the right screw instantly. Keeps your workspace tidy and speeds up project progress, making every job smoother.
【Hex Socket Button & Cap Head】- The metric M3 screws set comes with 2300 pieces, including 286pcs M3-0.5 x 4mm/6mm/8mm/12mm/16mm/20mm/25mm/30mm/35mm hex socket head cap bolts. 286pcs M3-0.5 x 4mm/6mm/8mm/12mm/16mm/20mm/25mm/30mm/35mm hex socket button...
【Perfect for DIY Projects】 This m3 small screws assortment kit are ideal for hobbyists working with 3D printing, electronics, RC models, RC car enthusiasts, DIY, chair replacement and CNC machinery, offering precision for intricate designs.
【High Quality】- These 3m screws assorted kit are crafted from high-strength 10.9 &12.9 grade alloy steel and black zinc plated, ensuring exceptional durability and load-bearing capacity. High-strength steel resists wear, corrosion, and heavy loads...
【Wide Applications】Keep a m3 machine screw variety set at hand. Whether you are working on DIY projects, bicycle repairs, or professional construction, it can meet your needs at any time, making your work more convenient and efficient.
1.Premium 304 SUS Material,Our Hex Socket Head bolt & nuts set is made by high quality 304 SUS, which have superior rust resistance and excellent oxidation resistance, can ensure long time workable and useful
2. Various Sizes,This nice screws set have M3,M4,M5,M6 models , besides each model have different length ( 6 to 35 mm ) to choose,which can meet most demands in daily.M3 ,6/8/10/12mm ;M4 ,8/10/16/20mm ;M5 ,10/ 16/20/30 mm;M6 ,16/25/35 mm
3.Quality& Technology,HVAKHVA are speclized in fasten area for many years, and this hex socket Head bolt have threaded in the head which make it more easy to use
Valuable M2.5 Screw Kit：You will get 1001pcs M2.5 x 4mm/6mm/8mm/10mm/12mm/16mm/20mm hex socket head cap screws with matching hex nuts, lock washers and flat washers, it has enough variety to cover all your needs
High Quality Materials: VGBUY m2.5 screws are made of high-quality 12.9 grade alloy steel,which features is corrosion, rust resistance,and high hardness,they can with stand heavy loads and offer a long service life
Widely Used: This m2.5 screw kit can be used for various builds & fix it projects,including 3D printing and RC car hobbyists,small electronics projects, machinery repair, DIY projects, etc
Organized Storage Box: The M2.5 screws kit is packed in a reinforced, labeled box with separate compartments and sturdy latches. This prevents them from being scattered or lost, and the organized case makes it easy to keep everything tidy and accessible
Last update on 2026-10-14 / Affiliate links / Images from Amazon Product Advertising API
How to Choose the Best Socket Head Screws
Understanding Socket Head Screw Types
Cap Screws (Socket Head Cap Screws): These are the most common type, featuring a cylindrical head with a hexagonal socket. They are ideal for applications requiring strength and a flush or countersunk finish.
Set Screws (Socket Set Screws): These screws lack a head and are designed to secure an object within or against another object. They are often used to prevent relative motion between parts, like fastening a pulley to a shaft.
Button Head Screws: With a low-profile, rounded head, these offer a clean aesthetic and are suitable for areas where a protruding head is undesirable.
Flat Head Screws: These have a countersunk head that sits flush with the surface, providing a smooth finish. They are often used in conjunction with a countersunk hole.
Material Matters
Stainless Steel: Offers excellent corrosion resistance, making it suitable for outdoor or wet environments. Grades like 18-8 (304) and 316 provide varying levels of strength and resistance.
Alloy Steel: Typically heat-treated for high strength and durability, often coated with black oxide for moderate corrosion resistance and a sleek appearance.
Brass: Provides good corrosion resistance and is non-magnetic, often used in decorative applications or where electrical conductivity is a concern.
Plastic/Nylon: Lightweight and non-conductive, used in specific electronic or chemical applications where metal is unsuitable.
Choosing the Right Size and Thread
Diameter: Measured in fractions of an inch (e.g., #8, 1/4", 5/16") or millimeters. Ensure it matches the hole size and load requirements.
Length: Measured from the bearing surface to the tip. Select a length that allows for adequate thread engagement without bottoming out or protruding excessively.
Thread Pitch: Refers to the number of threads per inch (TPI) for standard UNC (coarse) or UNF (fine) threads. Coarse threads are stronger and easier to start, while fine threads offer finer adjustment and better resistance to vibration.
Frequently Asked Questions
What is the difference between a socket head cap screw and a socket set screw?
A socket head cap screw has a distinct cylindrical head with a hexagonal socket, used for joining components. A socket set screw, on the other hand, is headless and designed to secure one part against another, often to prevent movement.
Why are socket head screws often made of stainless steel?
Stainless steel offers superior resistance to rust and corrosion compared to many other metals. This makes socket head screws made from stainless steel ideal for use in humid environments, outdoors, or any application where exposure to moisture is likely.
How do I determine the correct length for a socket head screw?
Screw length is typically measured from the underside of the head to the tip of the screw. You need to ensure the screw is long enough to engage enough threads in the mating part for a secure hold, but not so long that it bottoms out or protrudes unnecessarily.
What does 'alloy steel' mean for a socket head screw?
Alloy steel indicates that the screw is made from a blend of steel and other elements, like chromium or molybdenum, to enhance its properties. These screws are often heat-treated to achieve high tensile strength and durability, making them suitable for demanding applications.
Are there specific tools needed for socket head screws?
Yes, socket head screws require a specific tool known as an Allen wrench or hex key. These wrenches fit into the hexagonal socket on the screw head, allowing you to apply torque to tighten or loosen them.
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