Hex bolts come in various sizes based on diameter, thread pitch, and length. Below is a standard dimension chart for common hex bolts
Metric Hex Bolt Dimensions
| NOMINAL SIZE (D) | BODY DIAMETER | HEAD THICKNESS | ACROSS THE FLATS | ACROSS CORNERS | ||||
|---|---|---|---|---|---|---|---|---|
| D (MAX) | D (MIN) | H (MAX) | H (MIN) | F (MAX) | F (MIN) | C (MAX) | C (MIN) | |
| m10 | 10.00 | 9.78 | 6.63 | 6.17 | 17.00 | 15.73 | 18.48 | 17.77 |
| m12 | 12.00 | 11.73 | 7.76 | 4.24 | 19.00 | 17.73 | 20.78 | 20.03 |
| m14 | 14.00 | 13.73 | 9.09 | 8.51 | 22.00 | 20.67 | 24.25 | 23.35 |
| m16 | 16.00 | 15.73 | 10.32 | 9.68 | 24.00 | 23.67 | 27.71 | 26.75 |
| m20 | 20.00 | 19.67 | 12.88 | 12.12 | 30.00 | 29.16 | 34.64 | 32.95 |
| m24 | 24.00 | 23.67 | 15.44 | 14.56 | 36.00 | 35.00 | 41.57 | 39.55 |
| m30 | 30.00 | 29.67 | 19.48 | 17.92 | 46.00 | 45.00 | 53.12 | 50.85 |
| m36 | 36.00 | 35.61 | 23.38 | 21.63 | 55.00 | 53.80 | 63.51 | 60.79 |
| m42 | 42.00 | 41.38 | 26.97 | 25.03 | 65.00 | 62.90 | 75.06 | 71.71 |
| m48 | 48.00 | 47.38 | 31.07 | 28.93 | 75.00 | 72.60 | 86.60 | 82.76 |
| m56 | 56.00 | 55.26 | 36.2 | 33.80 | 85.00 | 82.20 | 98.15 | 93.71 |
| m64 | 64.00 | 63.26 | 41.32 | 38.68 | 95.00 | 91.80 | 109.70 | 104.65 |
| m72 | 72.00 | 71.26 | 46.45 | 43.55 | 105.00 | 101.40 | 121.24 | 115.60 |
| m80 | 80.00 | 79.26 | 51.58 | 48.42 | 115.00 | 111.00 | 132.72 | 126.54 |
| m90 | 90.00 | 89.13 | 57.74 | 54.26 | 130.00 | 125.50 | 150.11 | 143.07 |
| m100 | 90.00 | 99.13 | 63.9 | 60.10 | 145.00 | 140.00 | 167.43 | 159.60 |
What Are Metric Hex Bolts?
Metric hex bolts are threaded fasteners with a hexagonal head, designed to be easily tightened using a wrench. Their hexagonal shape provides a secure grip, ensuring a reliable fastening in various applications.
These bolts follow the metric system, where dimensions are measured in millimeters, making them the standard in many countries worldwide. Choosing the right metric hex bolt involves balancing several important factors.
For instance, the diameter impacts the bolt’s strength. A larger diameter typically offers more strength but could add weight and cost to the project. In contrast, a smaller diameter might save space and money but could be inadequate for heavy-duty tasks, leading to potential failures.
It’s also crucial to consider the environment and the load the bolt will bear. While opting for bolts that are too large might seem like an easy solution, it can lead to over-engineering, causing unnecessary waste.
On the other hand, under sizing a bolt can risk structural integrity. Carefully selecting the right dimensions ensures optimal performance, safety, and cost-effectiveness in your project.
Key Dimensions of Metric Hex Bolts
To ensure a perfect fit, it’s essential to understand the key dimensions of a metric hex bolt, which include diameter, length, thread pitch, and more. Each of these dimensions impacts the bolt’s performance, and balancing them correctly is critical for a secure fastening.
Diameter
The diameter refers to the thickness of the bolt’s shank, determining its strength. Common metric bolt diameters include M6, M8, M10, and M12, where the number corresponds to the outer diameter in millimeters. A larger diameter increases the bolt’s load-bearing capacity, but it can also add unnecessary weight and cost. In contrast, choosing a smaller diameter may reduce costs and weight but could compromise its ability to support heavy loads.
Length
The length of the bolt, measured from under the head to the end of the threaded portion, plays a critical role in the connection’s effectiveness. Selecting the correct length ensures a secure fit, but using one that is too short or too long could lead to difficulties in tightening or inadequate holding power.
Thread Pitch
Thread pitch refers to the distance between threads on a bolt, measured in millimeters. Fine thread pitches offer better resistance to loosening, but they may be harder to install. Coarse thread pitches are easier to install but may not provide the same level of resistance to vibration or movement.
Bolt Head Type
The bolt head type, often hexagonal, affects the ease of installation and strength. The hex shape provides better grip and leverage, making tightening easier. Additionally, specialized head types, such as flange heads, may offer more contact surface for better distribution of load.
Choosing the right head type depends on the specific requirements of your project, balancing ease of installation with performance. In conclusion, considering each of these dimensions—diameter, length, thread pitch, and head type—helps you select the ideal metric hex bolt for your project, ensuring safety, cost-efficiency, and reliability.
How to Measure Metric Hex Bolts
To correctly identify the dimensions of a metric hex bolt, accurate measurement is essential. Properly measuring the diameter, length, and thread pitch ensures that the bolt fits its intended application. Here’s a step-by-step guide on how to measure these key aspects effectively.
Measuring Diameter
To measure the diameter, use a caliper to measure the thickness of the bolt’s shank, not including the threads. The diameter is typically labeled on the bolt itself, but verifying it is crucial. A larger diameter offers more strength but may also add cost and weight to the project, so balancing diameter with project needs is key. Opting for a diameter that’s too small might compromise the bolt’s strength, especially in high-stress applications.
Measuring Length
Next, measure the length of the bolt. This is done by measuring from directly under the bolt’s head to the end of the threaded portion. Ensure the length matches your application requirements; if it’s too short, the bolt may not secure the materials properly, while an excessively long bolt can be wasteful and difficult to tighten effectively. Select the length that ensures a snug, reliable fit without over-engineering.
Measuring Thread Pitch
Thread pitch is measured by determining the distance between adjacent threads. A thread pitch gauge or caliper is ideal for this measurement. Fine thread pitches, while providing better resistance to loosening, can be harder to install. Conversely, coarse threads are easier to install but may not hold as tightly under certain conditions, such as vibrations. Careful consideration of the application will help determine the best pitch.
By measuring these key dimensions accurately, you ensure that the right metric hex bolt is selected for your project, avoiding issues like poor fit or excess material usage. Each measurement plays a critical role in the bolt’s performance, so it’s important to balance precision with the specific needs of the job.
Common Applications of Metric Hex Bolts
Metric hex bolts are integral in various industries, including machinery, construction, and automotive. Their reliable performance makes them ideal for securing parts and ensuring structural integrity.
In machinery, for instance, hex bolts are essential for assembling components under high stress, where strength is critical. However, selecting the right dimensions—such as diameter and thread pitch—ensures the bolt can handle the load without adding unnecessary weight or cost.
In construction, the correct bolt size ensures stability and safety. Choosing a bolt with the wrong dimensions could result in weak joints or increased maintenance needs. Similarly, in the automotive industry, precise measurements are key for securing engine parts, as improper sizing could lead to failures under vibration or pressure.
How to Choose the Right Metric Hex Bolt for Your Project
Choosing the right metric hex bolt requires careful consideration of several factors, including material, load, and environmental conditions. Start by selecting the appropriate diameter and length to match the project’s requirements. For example, a larger diameter provides more strength but can increase weight and cost.
Additionally, thread pitch impacts installation and resistance to loosening, so balancing fine and coarse threads is essential. Furthermore, understanding common standards and specifications, such as ISO or DIN, helps ensure the bolt meets quality and safety standards. By weighing these factors, you’ll make an informed, reliable choice.
Standards and Specifications for Metric Hex Bolts
Metric hex bolts are produced according to international standards, such as ISO 4014 and DIN 933, ensuring uniformity, quality, and reliability. Adhering to these standards is essential for sourcing bolts that meet safety and performance expectations. For example, ISO 4014 specifies dimensions for bolts with hexagonal heads, while DIN 933 defines requirements for thread specifications.
When choosing bolts, it’s important to balance factors like strength, material, and coating based on project needs. Failing to consider these standards could result in poor performance, safety risks, or increased maintenance costs, making standard compliance critical for success.
Conclusion
In conclusion, understanding the key dimensions and specifications of metric hex bolts enables you to make informed, effective choices. Balancing factors like strength, cost, and size ensures the right bolt for your project. Choosing wisely impacts not only performance but also safety, durability, and long-term success.
FAQs
What is a metric hex bolt?
A metric hex bolt is a type of fastener with a hexagonal-shaped head designed to be tightened with a wrench. These bolts are measured in millimeters (metric system) and are widely used in industries such as construction, automotive, and machinery. They come in various sizes and specifications for different applications.
How do I measure the diameter of a metric hex bolt?
To measure the diameter of a metric hex bolt, use a caliper to measure the thickness of the bolt’s shank, excluding the threads. The diameter is usually marked on the bolt, but verifying it ensures accuracy. A larger diameter typically provides better strength but adds weight.
Why is thread pitch important when choosing a metric hex bolt?
Thread pitch refers to the distance between threads on a bolt. It’s crucial because it affects how tightly the bolt will hold and how easy it is to install. Fine threads offer better resistance to loosening but can be more challenging to install, while coarse threads are easier but may not provide as much grip under vibration.
What are the standard specifications for metric hex bolts?
Metric hex bolts are manufactured according to international standards, including ISO 4014 and DIN 933. These standards ensure uniformity in dimensions, thread specifications, and material quality, helping to guarantee performance, durability, and safety across applications.
How do I choose the right metric hex bolt for my project?
To select the right metric hex bolt, consider the material, load requirements, and environmental conditions of your project. Ensure the bolt’s diameter, length, and thread pitch match the specific needs. Additionally, refer to common standards like ISO or DIN to ensure the bolt meets required quality and safety levels.