Basic Info.
Model NO.
Support customization
Standard
DIN, ANSI, GB, JIS, BSW, GOST
Application
Machinery, Chemical Industry, Environmental, Building
Product Description
What is a Bolt?
A
bolt is a mechanical fastener consisting of a cylindrical shaft with external threads on part or all of its length, and a head at one end. It is designed to work in conjunction with a
nut to secure two or more objects together, or to be screwed into a pre-threaded hole (in the case of screws, which are similar but typically self-tapping). Bolts are fundamental in construction, manufacturing, and engineering, providing strong, reversible connections in countless applications.
Hexagon Head Bolt Specification Table
(Thread diameter: d; Pitch: P; Head thickness: A (max/min), B (max/min); Hexagon across flats: s (max/min) )
| Thread Specification (d) | Pitch (P) | Head Thickness A | Head Thickness B | Hexagon across flats (s) | | | | |
|---|
| | | max | min | max | min | | | |
| M1.6 | 0.35 | 1.22 | 0.98 | - | - | 3.2 | 3.02 | |
| M2 | 0.4 | 1.52 | 1.28 | - | - | 4 | 3.82 | |
| M2.5 | 0.45 | 1.82 | 1.58 | - | - | 5 | 4.82 | |
| M3 | 0.5 | 2.12 | 1.88 | - | - | 5.5 | 5.32 | |
| M3.5 | 0.6 | 2.52 | 2.28 | - | - | 6 | 6.78 | |
| M4 | 0.7 | 2.92 | 2.68 | 3 | 2.8 | 7 | 6.64 | |
| M5 | 0.8 | 3.65 | 3.35 | 3.74 | 3.26 | 8 | 9.78 | 7.64 |
| M6 | 1 | 4.15 | 3.85 | 5.04 | 4.56 | 10 | 10.73 | 10.57 |
| M7 | 1 | 4.95 | 4.65 | 5.04 | 4.56 | 11 | 12.73 | 10.57 |
| M8 | 1.25 | 5.45 | 5.15 | 5.54 | 5.11 | 13 | 16.73 | 12.57 |
| M10 | 1.5 | 6.56 | 6.22 | 6.99 | 6.21 | 17 | 18.67 | 16.57 |
| M12 | 1.75 | 7.68 | 7.32 | 7.79 | 8.51 | 19 | 21.67 | 18.48 |
| M14 | 2 | 8.98 | 8.62 | 9.09 | 9.71 | 22 | 23.67 | 21.16 |
| M16 | 2 | 10.16 | 9.82 | 10.29 | 9.71 | 24 | 26.67 | 23.16 |
| M18 | 2.5 | 11.72 | 11.28 | 11.85 | 11.15 | 27 | 29.67 | 26.15 |
| M20 | 2.5 | 12.72 | 12.28 | 12.85 | 12.15 | 30 | 31.61 | 29.16 |
| M22 | 2.5 | 14.22 | 13.78 | 14.35 | 13.65 | 32 | 35.38 | 31 |
| M24 | 3 | 15.22 | 14.78 | 15.35 | 14.65 | 36 | - | 35 |
| M27 | 3 | - | - | 17.35 | 16.65 | 41 | - | 40 |
| M30 | 3.5 | - | - | 19.12 | 18.28 | 46 | - | 45 |
| M33 | 3.5 | - | - | 21.42 | 20.58 | 50 | - | 49 |
| M36 | 4 | - | - | 22.92 | 22.08 | 55 | - | 53.8 |
| M39 | 4 | - | - | 25.42 | 24.58 | 60 | - | 58.8 |
| M42 | 4.5 | - | - | 26.24 | 25.38 | 65 | - | 63.1 |
| M45 | 4.5 | - | - | 28.42 | 27.58 | 70 | - | 68.1 |
| M48 | 5 | - | - | 30.42 | 29.58 | 75 | - | 73.1 |
| M52 | 5 | - | - | 33.25 | 32.5 | 80 | - | 78.1 |
Notes:
- Parameters:
- d: Thread diameter; L: Thread length (excluding head); k: Head thickness; dc: Head diameter; s: Hexagon across flats; P: Pitch.
- The data is for batch sampling measurement, with certain tolerances. Please refer to the actual product for accuracy.
- Unit:All dimensions are in millimeters (mm).
Key Components
Head
- The most common type is the hexagonal head, which allows tightening/loosening with wrenches or sockets.
- Other head styles include:
- Round head (for aesthetic purposes, e.g., furniture).
- Flat head (sits flush with the surface, used in countersunk holes).
- Socket head (for Allen wrenches, common in precision machinery).
- Carriage bolt (rounded head with a square shank to prevent spinning in wood).
Shank
- The unthreaded portion between the head and threads, often used to position the bolt accurately.
- May be fully threaded or partially threaded, depending on the application.
Threads
- Standardized to match nuts or tapped holes, with options like metric threads (ISO, e.g., M6, M12) or inch-based threads (UNC/UNF, e.g., 1/4"-20).
- Thread pitch (distance between threads) varies: fine threads offer better vibration resistance, while coarse threads are quicker to assemble.
Materials and Coatings
Common Materials
- Steel: Carbon steel (cost-effective, suitable for general use) or alloy steel (high-strength, heat-treated for industrial applications).
- Stainless steel (e.g., 304, 316): Corrosion-resistant, ideal for marine, medical, or outdoor environments.
- Aluminum/Brass: Lightweight or non-magnetic (aluminum) and corrosion-resistant (brass), used in electronics or decorative applications.
Surface Treatments
- Zinc plating: Enhances rust resistance (e.g., yellow or clear zinc).
- Hot-dip galvanizing: Heavy-duty protection for outdoor/industrial use.
- Black oxide: Provides a sleek, rust-resistant finish with minimal thickness.
- Dacromet/Geomet: Advanced coatings for extreme corrosion resistance (e.g., automotive or offshore industries).
Types of Bolts
| Type | Key Features | Applications |
|---|
| Hex Bolt | Hexagonal head, standard design for general use | Construction, automotive, machinery |
| Carriage Bolt | Rounded head with a square shank to grip wood | Woodworking, furniture, structural connections |
| Socket Head Cap Screw | Cylindrical head with a hexagonal socket, provides high torque | Precision machinery, aerospace, robotics |
| Anchor Bolt | Embedded in concrete to secure structures (e.g., J-bolt, L-bolt shapes) | Building foundations, bridges, heavy equipment |
| Stud Bolt (Stud) | Threaded on both ends, no head; used in through-holes or with double nuts | Pipe flanges, engines, pressure vessels |
| High-Tensile Bolt | Heat-treated for maximum strength, often used in structural joints | Industrial machinery, cranes, steel frameworks |
| Stainless Steel Bolt | Corrosion-resistant, suitable for harsh environments | Marine equipment, chemical plants, food processing |
Functions and Applications
- Securing Structures: Bolts are critical in assembling steel beams, bridges, and buildings, often used with nuts to create rigid connections.
- Machinery Assembly: In engines, motors, and industrial equipment, bolts hold components like gears, housings, and brackets in place.
- Transportation: Used in automotive, aerospace, and rail industries to fasten parts like wheels, engines, and aircraft frames.
- DIY and Furniture: Carriage bolts and flat-head bolts are popular for woodworking and furniture assembly due to their flush fit and anti-spin features.
Why Bolts Matter
Bolts embody the backbone of modern engineering, combining simplicity with versatility. Their reusable design allows for easy maintenance, while advancements in materials (e.g., high-strength alloys) and coatings have expanded their use in extreme conditions. Made in China bolts are renowned for their consistent quality, competitive pricing, and adherence to international standards (ISO, ASTM), supporting global supply chains in sectors from renewable energy to consumer electronics.
From tiny bolts in smartphones to massive anchor bolts in skyscrapers, these unassuming fasteners ensure the world stays connected-one thread at a time.
Address:
N/a, Yantai, Shandong, China
Business Type:
Trading Company
Business Range:
Industrial Equipment & Components, Manufacturing & Processing Machinery
Management System Certification:
GMP
Company Introduction:
Different kinds of products are available in our company. We′re pleased to get your Inquiry and we will reply you as soon as possible. We stick to the principle of "quality first, service first, continuous improvement and innovation to meet the customers" for the management and "zero defect, zero complaints" as the quality objective.
