Metric socket head cap screws are essential in many mechanical and engineering projects because they are strong and easy to use. This guide will explore their size chart, helping you pick the right size for your needs. Understanding these sizes is crucial, as choosing the wrong one can impact your project’s success.
Metric Socket Head Cap Screws Size Chart
SOCKET HEAD CAP SCREW – METRIC
| Size | Diameter | Head Diameter | Head Height | Hexagon Socket Size | Key Engagement |
|---|---|---|---|---|---|
| M3-0.5 | 3.00 | 5.50 | 3.00 | 2.50 | 1.50 |
| M4-0.7 | 4.00 | 7.00 | 4.00 | 3.00 | 2.00 |
| M5-0.8 | 5.00 | 8.50 | 5.00 | 4.0 | 2.50 |
| M6-1.0 | 6.00 | 10.00 | 6.00 | 5.00 | 3.00 |
| M8-1.25 | 8.00 | 13.00 | 8.00 | 6.00 | 4.00 |
| M10-1.50 | 10.00 | 16.00 | 10.00 | 8.00 | 5.00 |
| M12-1.75 | 12.00 | 18.00 | 12.00 | 10.00 | 6.00 |
| M14-2.0 | 14.00 | 21.00 | 14.00 | 12.00 | 7.00 |
| M16-2.0 | 16 | 24.00 | 16.00 | 14.00 | 8.00 |
| M18- | |||||
| M20-2.50 | 20.00 | 30.00 | 20.00 | 17.00 | 10.00 |
| M22 | 24.00 | ||||
| M24-3.0 | 24.00 | 36.00 | 24.00 | 19.00 | 12.00 |
| M27 | |||||
| M30-3.50 | 30.00 | 45.00 | 30.00 | 22.00 | 15.00 |
| M36-4.0 | 36.00 | 54.00 | 36.00 | 27.00 | 18.00 |
| M42-4.5 | 42.00 | 63.00 | 42.00 | 32.00 | 21.00 |
| M48-5.0 | 48.00 | 72.00 | 48.00 | 36.00 | 24.00 |
SOCKET SET SCREWS – METRIC
| Size | Knurl & Cup Point Diameter | Flat Point Diameter | Oval Point Radius | Half Dog Point Diameter | Half Dog Point Length | Hexagon Socket Size | Key Engagement |
|---|---|---|---|---|---|---|---|
| M1.6-0.35 | 0.80 | 0.80 | 1.600 | 0.80 | 0.53 | 0.70 | 0.60 |
| M2-0.04 | 1.00 | 1.00 | 1.90 | 1.00 | 0.64 | 0.90 | 0.80 |
| M2.5-0.45 | 1.25 | 1.50 | 2.28 | 1.50 | 1.25 | 1.30 | 1.10 |
| M3-0.50 | 1.50 | 2.00 | 2.65 | 2.00 | 1.75 | 1.50 | 1.50 |
| M4-0.70 | 2.00 | 2.50 | 3.80 | 2.50 | 1.20 | 2.00 | 1.80 |
| M5-0.80 | 2.50 | 3.50 | 4.55 | 3.50 | 1.37 | 2.50 | 2.70 |
| M6-1.00 | 3.00 | 4.00 | 5.30 | 4.00 | 1.74 | 3.00 | 3.00 |
| M8-1.25 | 4.00 | 5.50 | 6.80 | 5.50 | 2.28 | 4.00 | 4.00 |
| M10-1.50 | 5.00 | 7.00 | 8.30 | 7.00 | 2.82 | 5.00 | 5.00 |
| M12-1.75 | 6.00 | 8.50 | 9.80 | 8.50 | 3.35 | 6.00 | 6.00 |
| M16-2.00 | 8.00 | 12.00 | 12.80 | 12.00 | 4.40 | 8.00 | 8.00 |
| M20-2.50 | 10.00 | 15.00 | 15.80 | 15.00 | 5.45 | 10.00 | 9.00 |
SOCKET HEAD SHOULDER SCREW – METRIC
| Size | Shoulder Diameter | Head Diameter | Head Height | Hexagon Socket Size | Key Engagement | Thread Pitch | Thread Length |
|---|---|---|---|---|---|---|---|
| 6.00 | 5.990 | 10.00 | 4.500 | 3.00 | 5.00-.08 | 9.750 | |
| 8.00 | 7.987 | 13.00 | 5.500 | 4.00 | 6.00-1.0 | 11.25 | |
| 10.00 | 9.987 | 16.00 | 7.00 | 5.00 | 8.00-1.25 | 13.25 | |
| 12.00 | 11.984 | 18.00 | 8.00 | 6.00 | 10.0-1.50 | 16.40 | |
| 16.00 | 15.984 | 24.00 | 11.00 | 8.00 | 12.0-1.75 | 18.40 | |
| 20.00 | 19.980 | 30.00 | 14.00 | 10.00 | 16-2.00 | 22.40 |
FLAT HEAD SOCKET CAP SCREW – METRIC
| Size | Head Diameter | Head Height | Hexagon Socket Size | Key Engagement |
|---|---|---|---|---|
| M3-0.5 | 6.72 | 1.86 | 2.00 | 1.10 |
| M4-0.7 | 8.96 | 2.48 | 2.50 | 1.50 |
| M5-0.8 | 11.20 | 3.10 | 3.00 | 1.90 |
| M6-1.0 | 13.44 | 3.72 | 4.00 | 2.20 |
| M8-1.25 | 17.92 | 4.96 | 5.00 | 3.00 |
| M10-1.50 | 22.40 | 6.20 | 6.00 | 3.60 |
| M12-1.75 | 26.88 | 7.44 | 8.00 | 4.30 |
| M16-2.00 | 33.60 | 8.80 | 10.00 | 4.80 |
| M20-2.50 | 40.32 | 10.16 | 12.00 | 5.60 |
BUTTON HEAD SOCKET CAP SCREW – METRIC
| Size | Head Diameter | Head Height | Hexagon Socket Size | Key Engagement |
|---|---|---|---|---|
| M3-0.5 | 5.700 | 1.65 | 2.00 | 1.04 |
| M4-0.7 | 7.60 | 2.20 | 2.50 | 1.30 |
| M5-0.8 | 9.50 | 2.75 | 3.00 | 1.56 |
| M6-1.0 | 10.50 | 3.30 | 4.00 | 2.08 |
| M8-1.25 | 14.00 | 4.40 | 5.00 | 2.60 |
| M10-1.50 | 17.50 | 5.50 | 6.00 | 3.12 |
| M12-1.75 | 21.00 | 6.60 | 8.00 | 4.16 |
METRIC SOCKET HEAD CAP SCREWS – MECHANICAL PROPERTIES
| Size | Thread Stress Area (mm^2) | Yield Strength (kN) | Tensile Strength (kN) | Single Shear Strength Threads (kN) | Single Shear Strength Body (kN) |
|---|---|---|---|---|---|
| M2-0.4 | 2.07 | 2.28 | 2.53 | 1.57 | 1.99 |
| M3-0.5 | 5.03 | 5.53 | 6.14 | 3.81 | 4.7 |
| M4-0.7 | 8.78 | 9.63 | 10.7 | 6.63 | 8.39 |
| M5-0.8 | 14.2 | 15.6 | 17.3 | 10.7 | 13.4 |
| M6-1.0 | 20.1 | 22.1 | 24.5 | 15.2 | 19.5 |
| M8-1.25 | 36.6 | 40.1 | 44.6 | 27.7 | 34.8 |
| M10-1.5 | 58 | 63.7 | 70.8 | 43.9 | 55 |
| M12-1.75 | 84.3 | 92.7 | 103 | 63.9 | 79.1 |
| M16-2.0 | 157 | 173 | 192 | 119 | 142 |
| M20-2.5 | 245 | 269 | 299 | 185 | 222 |
| M24-3.0 | 353 | 388 | 431 | 267 | 327 |
| M30-3.5 | 561 | 616 | 684 | 424 | 506 |
| M36-4.0 | 817 | 897 | 997 | 618 | 729 |
METRIC SOCKET HEAD CAP SCREW -TORQUE VALUES
| Size | Stress Area (mm^2) | Clamp Load (lbs) | Torque K=.2 (Nm) | Clamp Load(lbs) | Torque K=.2 |
|---|---|---|---|---|---|
| M2-.04 | 2.07 | 1.51 | 0.6 | 340 | 85 In-Oz |
| M3-0.5 | 5.03 | 3.66 | 2.2 | 823 | 19 In-lbs |
| M4-0.7 | 8.78 | 6.39 | 5.11 | 1437 | 45 In-lbs |
| M5-0.8 | 14.2 | 10.4 | 10.4 | 2338 | 92 In-lbs |
| M6-1.0 | 20.1 | 14.6 | 17.5 | 3282 | 13 Ft-lbs |
| M8-1.25 | 36.6 | 26.6 | 42.6 | 5980 | 31 |
| M10-1.5 | 58 | 42.2 | 84 | 9487 | 62 |
| M12-1.75 | 84.3 | 61.4 | 147 | 13800 | 108 |
| M16-2.0 | 157 | 114 | 365 | 25630 | 269 |
| M20-2.5 | 245 | 179 | 716 | 40240 | 528 |
| M24-3.0 | 353 | 257 | 1234 | 57775 | 910 |
| M30-3.5 | 561 | 408 | 2448 | 91720 | 1806 |
| M36-4.0 | 817 | 594 | 4277 | 133540 | 3155 |
Understanding Metric Socket Head Cap Screws
Definition and Design
Metric socket head cap screws stand out due to their cylindrical heads with hexagonal sockets. This design not only provides a sleek, flush finish but also allows for high-torque application.
However, while their unique design ensures a secure fit and reliable performance, it can also limit their use in spaces with restricted access. Choosing the right design is crucial, as it impacts both the ease of installation and the screw’s effectiveness in holding components together.
Common Applications
These screws are highly valued in machinery, automotive parts, and construction for their strength and precision. They are preferred in applications requiring tight tolerances and high strength. Nevertheless, the choice of using metric socket head cap screws over other types can involve trade-offs, such as the need for specific tools and potentially higher costs. Balancing these factors is essential to ensure that the screws meet the demands of your project while considering their impact on overall performance and budget.
Selecting the Right Size
Choosing the right size of metric socket head cap screw is crucial and involves evaluating specific factors related to your application, such as load-bearing capacity and material thickness.
Application Requirements
First, assess the demands of your application to determine the appropriate diameter and length of the screw. For example, a higher load-bearing requirement may necessitate a larger diameter, while a specific length is needed to ensure a secure fit. However, selecting a size that is too large or too small can compromise both the performance and safety of the assembly.
Material and Load Factors
Additionally, consider the material of the components being fastened and the load they will bear. The material affects how the screw interacts with the surface and influences the overall durability of the connection. For instance, using a screw that is too small may not provide sufficient strength, while a screw that is too large might cause damage. Balancing these factors is essential to achieve the right fit and ensure that the screws perform effectively while avoiding potential issues related to overloading or material damage.
FAQs
1. What is the difference between metric socket head cap screws and other types of screws?
Answer: Metric socket head cap screws feature a cylindrical head with a hexagonal socket, which allows for a clean, flush finish and high torque application. This design contrasts with other screws like Phillips or flathead, which have different drive types and may not offer the same torque capability or aesthetic. The hexagonal socket makes metric socket head cap screws ideal for applications requiring precise and secure fastening.
2. How do I determine the correct size of a metric socket head cap screw for my project?
Answer: To select the right size, you need to consider the application’s specific requirements, including the diameter and length needed for a secure fit. Assess the load-bearing capacity and material thickness of the parts you are fastening. For instance, heavier loads may require larger diameters, while the length should match the depth of the hole or material thickness. Ensure that the chosen screw size fits well within these parameters to achieve optimal performance.
3. What are the common challenges when using metric socket head cap screws, and how can I address them?
Answer: Common challenges include ensuring proper torque application and selecting the right size for your application. If the screw is too small, it may not handle the required load, whereas a screw that’s too large can damage the material or cause installation issues. To address these challenges, accurately measure your components and consider using a torque wrench to apply the correct amount of torque. Additionally, ensure that the screw size aligns with the specifications of your project to avoid issues with fit and performance.