Allen bolts are an essential part of many projects and machines, but their wide range of sizes can be confusing. With this guide, you'll be able to confidently select the right Allen bolt for the task at hand with our helpful size chart and reference guide.

Understanding the Different Bolt Sizes.
Allen bolts come in a variety of different sizes and lengths, each with its own unique threading specification and diameter. To find the size you need, look for the two numbers on the head of the bolt. The first number is typically between 0 and 10, while the second number is usually between 1/16 and 1 inch. You can then use those measurements to cross-reference the correct size on our bolt sizing chart.

Different Types of Allen Bolts and Their Uses.
Allen bolts come in many different materials, allowing them to be used in a variety of settings - from heavy-duty applications with steel bolts to light duty tasks with brass bolts. Choosing the right type of Allen bolt depends on the weight and pressure required, as well as any other mechanical needs you may have. Steel will offer strength and durability while brass is perfect for lightweight projects needing less structural integrity.

How to Measure an Allen Bolt for Replacement/Replication.
The size of an Allen bolt is determined by the diameter of its shaft and its thread count. To measure the diameter, use a caliper to directly record your measurements in millimeters or inches. For measurements in fractions of an inch, subtract 1/64 for every additional fraction (1/4 inch = 0.25 - 1/64 = 0.23). To measure the thread count, count the number of threads per inch or millimeter on the bolt from one end to the other.

Different Grades of Allen Bolts and Their Ratings.
Another factor to consider when selecting Allen bolts is its grade rating. Grade ratings indicate the strength of a particular bolt, which affects its load-bearing capacity. Common grades include Grade 5, Grade 8 and some metric grades such as 8.8 and 10.9. Grade 5 bolts are composed of medium-carbon steel, allowing for good tensile strength and typically used in construction applications; Grade 8 bolts are made from alloy steel and feature a tensile strength up to 150ksi; metric grades 8.8 and 10.9 feature the highest tensile strengths at clamps over 130ksi and 150ksi, respectively. It’s important to be aware of the grade rating when selecting a bolt for your application as it ensures that your fastener is up to task!

Tips for Buying Allen Bolts in Bulk Quantities.
When purchasing bulk quantities of Allen bolts, it’s important to buy the right amount and type of product. Before buying in bulk, consider the number of projects that you have on hand or any special features needed for your project such as bolt length or finish. Additionally, if a store offers quantity discounts, take advantage of it! By buying in large quantities your purchase will be more cost-effective overall. Finally, check that the product meets minimum standards for strength and safety by verifying the material grade before you purchase.