Allen key bolts, also known as hex key bolts, are essential for many DIY and professional projects. They offer a secure and reliable fastening solution. Choosing the right size is crucial to avoid damage and ensure a proper fit. This guide helps you navigate these choices effectively.
Short Arm SAE Allen Wrench Dimensions (Hex Key)
| Hex Allen Key Sizes | Width Across Flats Max | Width Across Flats Min | Length of Long Arm | Length of Short Arm |
| 0.028″ | 0.028″ | 0.0275″ | 1.219″ | 0.219″ |
| 0.035″ | 0.035″ | 0.0345″ | 1.219″ | 0.344″ |
| 0.050″ | 0.050″ | 0.049″ | 1.656″ | 0.531″ |
| 1/16″ | 0.0625″ | 0.0615″ | 1.75″ | 0.562″ |
| 5/64″ | 0.0781″ | 0.0771″ | 1.875″ | 0.609″ |
| 3/32″ | 0.0937″ | 0.0927″ | 2″ | 0.656″ |
| 7/64″ | 0.1093″ | 0.1077″ | 2.125″ | 0.703″ |
| 1/8″ | 0.1250″ | 0.1235″ | 2.25″ | 0.75″ |
| 9/64″ | 0.1406″ | 0.1391″ | 2.375″ | 0.796″ |
| 5/32″ | 0.1562″ | 0.1547″ | 2.5″ | 0.844″ |
| 3/16″ | 0.1875″ | 0.1860″ | 2.75″ | 0.938″ |
| 7/32″ | 0.2187″ | 0.2172″ | 3″ | 1.031″ |
| 1/4″ | 0.250″ | 0.248″ | 3.25″ | 1.125″ |
| 5/16″ | 0.3125″ | 0.3110″ | 3.75″ | 1.25″ |
| 3/8″ | 0.375″ | 0.373″ | 4.25″ | 1.375″ |
| 7/16″ | 0.4375″ | 0.4355″ | 4.75″ | 1.5″ |
| 1/2″ | 0.50″ | 0.04975″ | 5.25″ | 1.625″ |
| 9/16″ | 0.5625″ | 0.56″ | 5.75″ | 1.75″ |
| 5/8″ | 0.625″ | 0.6225″ | 6.25″ | 1.875″ |
| 3/4″ | 0.75″ | 0.747″ | 7.25″ | 2.125″ |
| 7/8″ | 0.875″ | 0.872″ | 8.25″ | 2.375″ |
| 1″ | 0.050″ | 0.049″ | 1.656″ | 0.531″ |
Short Arm Metric Allen Wrench Dimensions (Hex Key)
| Hex Allen Key Sizes | Width Across Flats | Width Across Flats | Length of Long Arm | Length of Long Arm | Length of Short Arm | Length of Short Arm |
| Max | Min | Max | Min | Max | Min | |
| 0.9 | 0.899 | 0.876 | 34 | 28 | 11 | 6 |
| 1.3 | 1.270 | 1.244 | 44 | 39 | 16 | 11 |
| 1.5 | 1.5 | 1.47 | 45 | 43 | 14 | 13 |
| 2 | 2.00 | 1.97 | 50 | 48 | 16 | 15 |
| 2.5 | 2.50 | 2.47 | 56 | 53 | 18 | 17 |
| 3 | 3.00 | 2.96 | 63 | 60 | 20 | 18 |
| 4 | 4.00 | 3.96 | 70 | 66 | 25 | 23 |
| 5 | 5.00 | 4.96 | 80 | 76 | 28 | 26 |
| 6 | 6.00 | 5.95 | 90 | 86 | 32 | 30 |
| 8 | 8.00 | 7.95 | 100 | 95 | 36 | 34 |
| 10 | 10.00 | 9.95 | 102 | 106 | 40 | 38 |
| 12 | 12.00 | 11.95 | 125 | 119 | 45 | 43 |
| 14 | 14.00 | 13.95 | 140 | 133 | 56 | 53 |
| 17 | 17.00 | 16.93 | 160 | 152 | 63 | 60 |
| 19 | 19.00 | 18.93 | 280 | 271 | 70 | 67 |
Long Arm SAE Hex Key Dimensions (Hex Key)
| Hex Allen Key Sizes | Width Across Flats Max | Width Across Flats Min | Length of Long Arm | Length of Short Arm |
| 0.050″ | 0.050″ | 0.049″ | 2.844″ | 0.531″ |
| 1/16″ | 0.0625″ | 0.0615″ | 3″ | 0.562″ |
| 5/64″ | 0.0781″ | 0.0771″ | 3.188″ | 0.609″ |
| 3/32″ | 0.0937″ | 0.0927″ | 3.375″ | 0.656″ |
| 7/64″ | 0.1093″ | 0.1077″ | 3.562″ | 0.703″ |
| 1/8″ | 0.1250″ | 0.1235″ | 3.75″ | 0.75″ |
| 9/64″ | 0.1406″ | 0.1391″ | 3.937″ | 0.796″ |
| 5/32″ | 0.1562″ | 0.1547″ | 4.125″ | 0.844″ |
| 3/16″ | 0.1875″ | 0.1860″ | 4.5″ | 0.938″ |
| 7/32″ | 0.2187″ | 0.2172″ | 4.875″ | 1.031″ |
| 1/4″ | 0.250″ | 0.248″ | 5.25″ | 1.125″ |
| 5/16″ | 0.3125″ | 0.3110″ | 6″ | 1.25″ |
| 3/8″ | 0.375″ | 0.373″ | 6.75″ | 1.375″ |
| 7/16″ | 0.4375″ | 0.4355″ | 7.5″ | 1.5″ |
| 1/2″ | 0.50″ | 0.04975″ | 8.25″ | 1.625″ |
| 9/16″ | 0.5625″ | 0.56″ | 9″ | 1.75″ |
| 5/8″ | 0.625″ | 0.6225″ | 9.75″ | 1.875″ |
| 3/4″ | 0.75″ | 0.747″ | 11.25″ | 2.125″ |
| 7/8″ | 0.875″ | 0.872″ | 12.75″ | 2.375″ |
| 1″ | 0.050″ | 0.049″ | 14.25″ | 0.531″ |
Long Arm Metric Allen Wrench Dimensions (Hex Key)
| Hex Allen Key Sizes | Width Across Flats | Width Across Flats | Length of Long Arm | Length of Long Arm | Length of Short Arm | Length of Short Arm |
| Max | Min | Max | Min | Max | Min | |
| 1.5 | 1.5 | 1.47 | 78 | 76 | 14 | 13 |
| 2 | 2.00 | 1.97 | 83 | 81 | 16 | 15 |
| 2.5 | 2.50 | 2.47 | 90 | 87 | 18 | 17 |
| 3 | 3.00 | 2.96 | 100 | 97 | 20 | 18 |
| 4 | 4.00 | 3.96 | 106 | 102 | 25 | 23 |
| 5 | 5.00 | 4.96 | 118 | 114 | 28 | 26 |
| 6 | 6.00 | 5.95 | 140 | 136 | 32 | 30 |
| 7 | 7.00 | 6.97 | 145 | 140 | 36 | 34 |
| 8 | 8.00 | 7.95 | 160 | 155 | 36 | 34 |
| 10 | 10.00 | 9.95 | 170 | 164 | 40 | 38 |
Torx/Star Tamper Proof L Key Dimensions
| Drive Size | Length of Short Arm | Length of Long Arm |
| T-6 | 0.5″ | 1.65″ |
| T-7 | 0.55″ | 1.75″ |
| T-8 | 0.6″ | 1.85″ |
| T-9 | 0.65″ | 2″ |
| T-10 | 0.7″ | 2.1″ |
| T-15 | 0.75″ | 2.2″ |
| T-20 | 0.8″ | 2.35″ |
| T-25 | 0.85″ | 2.5″ |
| T-27 | 0.95″ | 2.75″ |
| T-30 | 1.05″ | 3″ |
| T-45 | 1.25″ | 3.75″ |
| T-50 | 1.35″ | 4.25″ |
| T-55 | 1.5″ | 4.75″ |
Hex Key / Allen Wrench Conversion Chart
| SAE Conversion for MM | SAE Conversion for MM | MM Conversion for SAE | MM Conversion for SAE |
| 5/64″ | 2 mm | 2 mm | 3/32″ |
| 3/32″ | 2.5 mm | 2.5 mm | 7/64″ |
| 7/64″ | 3 mm | 3 mm | 1/8″ |
| 1/8″ | 3.5 mm | 3.5 mm | 9/64″ |
| 5/32″ | 4 mm | 4 mm | 5/32″ |
| 3/16″ | 5 mm | 5.5 mm | 7/32″ |
| 7/32″ | 5.5 mm & 6 mm | 6 mm | 1/4″ |
| 1/4″ | 7 mm | 7 mm | 9/32″ |
| 5/16″ | 8 mm | 8 mm | 5/16″ |
| 3/8″ | 10 mm | 9 mm | 3/8″ |
What is an Allen Key Bolt?
An Allen key bolt, distinguished by its hexagonal socket, is designed to be driven by an Allen wrench, providing a tight and secure fit. However, choosing the right size involves tradeoffs. A bolt that’s too large or too small can cause damage or fail to hold properly. Additionally, the material of the bolt and the wrench can impact durability and performance.
Balancing these factors is crucial for successful projects. Considering these elements carefully helps ensure the Allen key bolt works effectively, highlighting the importance of an accurate Allen Key Bolt Size Chart.
Importance of Using the Correct Size
Using the correct size Allen key bolt is crucial to ensure a proper fit and prevent damage to both the bolt and the material being fastened. If the bolt is too small, it may not hold securely, leading to instability. Conversely, a bolt that’s too large can strip the threads or crack the material. Balancing these factors involves considering the specific requirements of the project and the materials used.
Additionally, different applications may require varying bolt strengths and sizes. Understanding these tradeoffs highlights the importance of an accurate Allen Key Bolt Size Chart to guide your choices.
How to Measure Allen Key Bolts
Accurately measuring Allen key bolts involves understanding their diameter, length, and thread pitch to match them with the corresponding Allen wrench. First, measure the diameter across the bolt’s threads, ensuring precision to avoid mismatches. Next, measure the bolt’s length from the base to the tip, excluding the head. Finally, determine the thread pitch by counting the number of threads per unit length.
However, challenges arise when bolts have non-standard dimensions or when working with worn or damaged bolts. Balancing these factors is crucial, as accurate measurements impact the effectiveness and safety of your project, emphasizing the need for a reliable Allen Key Bolt Size Chart.
Standard Sizes of Allen Key Bolts
Allen key bolts come in various standard sizes, typically measured in both metric and imperial units to accommodate different applications. Understanding these sizes is essential for selecting the right bolt for your project.
Metric Sizes
Metric Allen key bolts are commonly used worldwide and range from M1.6 to M64, each size denoting the bolt’s diameter in millimeters. However, choosing the appropriate metric size involves tradeoffs, such as balancing strength and weight. Larger bolts offer more strength but can add unnecessary weight and bulk.
Imperial Sizes
Imperial Allen key bolts, often used in the United States, are measured in inches and range from 1/16” to 2”, providing a broad spectrum of sizes. The challenge here lies in converting and comparing these sizes to metric ones, especially in projects requiring international standards. Balancing these factors is crucial for ensuring compatibility and performance.
By considering these elements, you can make informed decisions about which size to use, highlighting the importance of a comprehensive Allen Key Bolt Size Chart to guide your choices.
Applications of Different Allen Key Bolt Sizes
Different Allen key bolt sizes are used in a variety of applications, from assembling furniture to securing components in machinery. Smaller bolts, for instance, are ideal for precision tasks like electronics assembly, where space is limited and a delicate touch is required. However, these smaller bolts might not provide the necessary strength for heavy-duty tasks.
Larger bolts, on the other hand, are perfect for applications requiring substantial holding power, such as in automotive or industrial machinery. But, using larger bolts can pose challenges, such as increased weight and potential difficulty in fitting them into tight spaces.
Balancing these factors involves understanding the specific requirements of your project and the materials involved. For example, a project requiring frequent disassembly may benefit from using bolts that are easier to remove and replace. Conversely, permanent installations may prioritize strength and security.
Considering these tradeoffs highlights the importance of an accurate Allen Key Bolt Size Chart. It ensures you select the right bolt size for each application, optimizing both performance and durability.
Tips for Choosing the Right Allen Key Bolt
Selecting the right Allen key bolt involves considering factors such as the material, environment, and the required strength for the application. First, assess the material of the bolt and the material it will be fastened into. Stainless steel bolts, for example, offer excellent corrosion resistance, making them ideal for outdoor use, but they can be more expensive than other materials.
Next, consider the environment. Bolts used in high-temperature or high-humidity environments need to withstand these conditions without degrading. This might mean choosing specialized coatings or materials that resist heat and moisture.
Additionally, evaluate the required strength. For heavy-duty applications, such as securing structural components, you’ll need bolts that can handle high stress and load. However, stronger bolts might be more difficult to install and may require larger, more powerful tools.
Balancing these factors involves tradeoffs. You might need to compromise between cost and durability or ease of installation and strength. Understanding these tradeoffs helps in making an informed decision.
Considering the impact of each choice is crucial. An accurate Allen Key Bolt Size Chart can guide you in selecting the appropriate bolt for your specific needs, ensuring both effectiveness and longevity in your projects.
Maintaining and Storing Allen Key Bolts and Wrenches
Proper maintenance and storage of Allen key bolts and wrenches can prolong their lifespan and ensure they remain effective for future use. First, keep your tools and bolts clean. Dirt and grime can cause wear and corrosion, leading to decreased performance. Regularly wipe them down with a clean cloth and use a mild cleaner if necessary.
Next, store them in a dry, cool place to prevent rust and other damage. Moisture can cause bolts and wrenches to corrode, weakening their integrity. Use airtight containers or sealed bags for extra protection, especially in humid environments.
Organizing your bolts and wrenches by size can save time and prevent damage. Mixed or jumbled tools can lead to wear and tear as they rub against each other. Investing in a storage system with labeled compartments can make this easier.
Balancing the time and effort spent on maintenance with the benefits of prolonged tool life can be challenging. However, neglecting maintenance can result in higher costs over time due to frequent replacements.
Considering these tradeoffs is essential. Effective maintenance and storage practices not only extend the life of your tools but also ensure they function correctly when needed. This, in turn, helps you make informed decisions using the Allen Key Bolt Size Chart, ensuring you always have the right tools in good condition.
Conclusion
The Allen key bolt size chart is a useful tool for finding the size of any Allen key bolt. It is important to know the size of the Allen key bolt before beginning any project to ensure that you have the right size for the job. With the help of this chart, you can make sure that you have the right size Allen key bolt for your project.
FAQs
What are Allen key bolts?
Allen key bolts, also known as hex key bolts, are fasteners with a hexagonal socket designed to be driven by an Allen wrench. They are commonly used in various applications, from assembling furniture to securing components in machinery.
Why is it important to use the correct size Allen key bolt?
Using the correct size Allen key bolt ensures a proper fit and prevents damage to both the bolt and the material being fastened. An incorrect size can lead to instability, stripped threads, or cracked materials, compromising the integrity of the assembly.
How do I measure Allen key bolts accurately?
To measure Allen key bolts accurately, determine their diameter across the threads, measure the length from the base to the tip (excluding the head), and count the threads per unit length to identify the thread pitch. These measurements help match the bolt with the corresponding Allen wrench size.
What are the standard sizes of Allen key bolts?
Allen key bolts come in metric sizes (e.g., M1.6 to M64) and imperial sizes (e.g., 1/16” to 2”). Metric sizes denote the bolt’s diameter in millimeters, while imperial sizes are measured in inches, catering to different applications and regions.
How do different Allen key bolt sizes impact their applications?
Smaller Allen key bolts are ideal for precision tasks, like electronics assembly, while larger bolts are suitable for heavy-duty applications, such as automotive or industrial machinery. The choice of size depends on the required strength, space constraints, and specific project needs.