How to measure allen bolt size For standard bolts in the range of M5 – M12 sizes are available in Nov 23, 2018 · 3/8″ can be used as a substitute for hex size 9. How bolt sizes are expressed. Hex nuts are available in both metric and standard (Imperial) measurements: Metric Sizes: Common sizes include M6, M8, and M10. Metric vs. The diameter of a bolt is the Shank diameter, expressed in millimetres for Metric bolts. This rule for bolt length holds true for most types, including cheese, hex, pan, socket, button, and low socket head types. Start measuring the length of the bolt bar (L), and then measure the length of the half-threaded bolt (b Jul 28, 2024 · Flat head screws, for example, are measured by their overall length, including the head, and are used for flush mounting of sections. If you searched "How Are Fasteners Measured?" then you have come to the right place! Most commonly, screws and bolts are identified by diameter (of the threaded portion), thread pitch, and length. Nov 16, 2023 · Just as with diameter, both standard and metric bolt lengths are measured the same way. 5 mm as well as 10 mm; 1/16″ works in place of hex size 1. Mar 20, 2019 · The smaller size of Allen wrench can easily strip a hex bolt or be stripped down itself. How Do I Measure The Size Of An Allen Wrench? To measure the size of an Allen wrench, you need to determine the distance between the flat sides of the wrench. Elizabeth Fernandez / Getty Images. Since the length of the bolt is the last number in a metric measurement, you should measure for it last. Allen Screw Size Guide Jan 20, 2024 · 1. Hex tap bolts are a type of hex screw that has threading The measure rule of minor diameter – The distance from the bottom thread cavity from a particular side to the other. They are available in a variety of sizes, with the standard metric sizes defined in ISO 2936:2014 "Assembly tools for screws and nuts—Hexagon socket screw keys", also known as DIN 911. Determine the bolt size: Look at the hexagonal socket on the bolt. Example: 1/4"-10-24 x 7/8" = a shoulder bolt with a 1/4" diameter shoulder, #10-24 thread size and 7/8" shoulder length. 1. Shank Diameter Also called Major diameter. ” The basic thread lengths (LT) listed directly below the nominal sizes in the table above represents the nominal length up to which all screws of that diameter shall be fully threaded. Before placing the hex key into the bolt, make sure the head is clean of dirt and debris. 2. 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. The main dimensions to consider when choosing a bolt are diameter, length, and thread pitch, each contributing to the bolt’s strength and compatibility. Hexagon Keys are furnished as Short Arm Series or Long Arm Series. For Metric bolts. Feb 23, 2023 · Just as with diameter, both standard and metric bolt lengths are measured the same way. But using them effectively requires a bit of knowledge about allen wrench Aug 29, 2023 · As a result, it can be difficult to locate an accurate chart which covers a range of hex bolt types and sizes. Click on Size to Shop Products. Bolt dimensions as per ASME B18. Diameter (W): The diameter of a hex bolt is typically measured across the outer edges of its threads. When the head protrudes above the surface: Determining hex bolt dimensions is a good example. Gessner Houston, TX 77040-4015 Ph: 713-462-3147 sales@thenutplace. Apr 29, 2025 · To select the right SAE Allen wrench size for your needs, determine the bolt size, choose the appropriate wrench, and verify fit before use. The diameter refers to the outer measurement of the bolt, and selecting the right size ensures the bolt can withstand the required load. Measure the length of the bolts. For US/SAE bolts. How you measure bolt length depends on the bolt head dimension. This will then give you a rough number to try and find within your Allen wrenches. Allen ™ keys are identified as being either metric-sized keys in millimeter sizes or SAE (Imperial) sized keys in fractions of an inch or decimal equivalents. The nominal measurement is done by allotting a common number for sizes for 1/4" or lower. When specifying nuts and bolts for your application, it’s important to understand metric nut dimensions and metric bolt dimensions to select the correct fastener for the job. com www thenutplace com TOOLS FOR HEX HEAD BOLTS AND SOCKET HEADS METRIC Oct 19, 2010 · These dimensions of allen keys can be used to check the accessibility of your bolts were space is limited. Nov 14, 2024 · In this guide, I’ll walk you through the basics of bolt sizes and how to measure them. Taking the time to properly measure the wrench size will save you frustration, time, and potentially costly mistakes. For an 8mm thread, the allen key size is a 6mm hexagon. This excludes the head Jai Hind,About this video,how to calculate Allen bolt key size calculate,very simple trick formula for calculating of Allen bolt key size. 000” or very close to it without going over, whereas a one inch socket or wrench with measure a minimum of 1. Common metric sizes for hex bolts range from small diameters, such as 6 mm, to larger diameters exceeding 25mm. What DO all of these screw and bolt sizes mean? In this video, we break down how screws & bolts are sized and how the US measurement system and Metric measur How Do I Measure Bolts? Measuring Bolts and Screws. Bolt Gauge: A special tool to check the size of bolts. Sep 19, 2024 · The diameter of the Bolt is the actual size of the bolt and it is measured across the bolt shank or the threaded area. To manufacture or measure a thread, one has to know the maximum and minimum permissible values of the basic dimensions. Apr 3, 2024 · For those needing to identify the size of a bolt for an assembly, having a similar bolt on hand can simplify the process. Start from right below the head, including only the shank, and measure to the tip. M10 x 1. Use a ruler or a caliper to measure across the flats of the wrench. Thread Pitch: The distance between threads, measured in millimeters (for metric bolts) or as the number of threads per inch (for imperial bolts). #allenkey#allenbolt measure thread pitch. Dec 20, 2022 · Allen key sizes are measured across the flats of the hexagon (AF). For instance, assembling furniture or fixing your bike requires hex keys of different sizes. Nov 4, 2022 · To measure the size of an allen wrench, you can use either a hex key set with labeled sizes or a precision measuring tool such as a caliper. This is called the major diameter and will usually be the proper size of the bolt. Nov 22, 2024 · You may be wondering how to measure a metric bolt. The smaller hex keys are ideal for intricate jobs, such as tightening screws in hard-to-reach areas. Allen Key (Hex Key) and Hex Bit Sizes Chart to show dimensions of Allen keys (Hex keys) and bit sockets according to ASME B18. The M3 and M4 nominal screw sizes have two drilled holes spaced 180 degrees apart. Bodywork Flanged Hex Bolts; Vernier Calipers and a Thread Gauge to measure thread pitch. Size charts are crucial tools in the selection process, and they are an easy way to compare various hex nut sizes and their dimensions. These values are calculated according to the thread class . By Craig Lloyd. How do you measure the length of a hex bolt? Hex Bolts: For hex bolts, the length is measured from under the head to the tip. Jan 5, 2024 · Most at-home assembly furniture toolkits come with allen wrenches because of how cheap they are. Hex screws can be classified based on their threading, length, width, and material. Hex Bolt Dimensions (ANSI B18. If you’re looking to figure out the size of a Dec 5, 2024 · Ruler or Tape Measure: This is used to measure the length of the bolt. Steps to Measure Head Size: Dec 2, 2024 · Bolt length refers to the distance from a specified starting point to the tip of the bolt. These measurements help match the bolt with the corresponding Allen wrench size Dec 23, 2024 · Accurate measurement is the key to choosing the proper hex bolts for any project, ensuring their effectiveness and security in various applications. You'll also want to specify your threads per inch needed on the bolt. Follow Followed Like Allen wrench (hex key) size chart for long arm and short arm allen wrenches, torx/star keys. To understand classes, you first need to understand the terms Allowance (Sometimes referred to as deviation) and Tolerances. For fasteners where the head usually sits above the surface, the measurement is from directly under the head to the end of the fastener. 010”) Jan 18, 2024 · Using Hex Nut Size Charts. Whether you're a DIY enthusiast working on home Jun 13, 2024 · An Allen wrench, also known as a hex key, is a tool used to tighten and loosen hexagonal socket screws and bolts. Aug 14, 2024 · Manual Method: For metric bolts, measure the distance between two threads and use a ruler to read the measurement in millimetres. List shoulder diameter, then. For countersunk bolts, include the head in the measurement. 2. A quick swipe with a Q-tip dipped in rubbing alcohol will pick up any dust that can collect in the corners of the hexagon. com Fastener length is measured from where the material surface is assumed to be, to the end of the fastener. Hex keys measurements are done across-flats or AF. ), and come in a wide variety of sizes and shapes. Allen ™ wrenches are available as individual keys of a given size and are also sold in sets that contain a range of standard sizes. List shoulder length. This channel is related to Plant Management like plant design, Aug 16, 2024 · For bolts with a flat or countersunk head, the length is measured from the top of the head. Metric nuts and bolts are measured in millimetres. As long as you know how to measure a hex key, you can always determine the size you have. To determine the threaded portion of the screws with a nominal length greater than LT, subtract the minimum design grip length (LG) from the nominal length (L). Measure The Screw Hole. Whether one is assembling furniture, working on automotive projects, or engaged in construction, selecting the appropriate bolt is critical to ensuring safety and functionality. 3. The below data and explanations are based Dec 30, 2020 · A bolt’s size is classified based on a number of dimensions, namely the bolt’s diameter, length of shank, thread pitch, grade, thread length and head size. 0 x 30 means Metric 10mm bolt diameter with 1mm pitch and 30mm length See full list on wikihow. The diameter of the bolt’s shank is the first key dimension. Step To Measure Bolt Size Step 1 Measure the shank’s diameter. Thank goodness for this little bit of knowledge. Understanding how to correctly measure different attributes of hex bolts, such as length, diameter, thread pitch, and head size, is crucial in both amateur and professional construction fields. Measure the distance from the base (bottom) of the bolt’s head to the tip with a ruler or measuring tape. Standard Sizes. Provides dimensions for inch and metric allen wrenches. Use calipers or a bolt gauge for an accurate measurement. Whether you’re an expert or just getting started, you’ll be able to measure bolts accurately every time. Published Jul 18, 2017. Feb 10, 2023 · 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. Follow these detailed steps: Step 1: Measure the Shank’s Diameter. Apr 7, 2021 · Allen ™ Wrench/Key Size Charts. Understanding bolt sizes is essential for both DIY enthusiasts and professional tradespeople, especially when learning how to measure bolt size accurately. . This might assist you in determining the size of Allen key you require or need to have on hand. Measuring the Head Size of a Bolt. Nov 6, 2024 · "Make More knowledge in less time. Bolts can me specified in metric using millimeters, but the standard, internationally-recognized descriptions of bolt sizes are in inches. Imperial and metric measurements included. E. The size of an Allen screw can vary, with drilled head metric hexagon socket head cap screws typically available in sizes ranging from M3 to M36. Nov 8, 2024 · Hex head screws and bolts are measured from right under the head to the end of the threads. Jun 6, 2024 · The full-threaded bolt only needs to measure a bottom diameter (d), and the half-threaded bolt needs to measure the diameter of the unthreaded part (ds) to record the values measured in the notebook. An Allen key size chart is frequently included with self-assembled furniture, such as infant cribs, outdoor swings, or computer tables. Allen keys, also known as hex keys, are used for bolts or screws with heads that have internal hexagonal recesses (sockets). a new one inch bolt or nut should measure exactly 1. 5 mm, which isn’t included in most sets; When you reference the hex key conversion chart above, do be aware that using a smaller size bit will increase your vulnerability for stripping the hardware. Oct 27, 2024 · Metric sizes. Because this is approximately the same as the Major or Inch Shoulder Bolts: 1. For example for an M8 socket head cap screw we need at least 32+8(head size) = 40mm clearance above the screw for easy accessibility. The body length of the bolt is measured from the tip of the bolt to the point where the shank meets the head. I have also explained to calculate the size of the Allen key accordin How do I determine which hex bolt head size to use for my application using the hex bolt head size chart? You can determine the appropriate hex bolt head size for your application by considering factors such as the load that will be placed on the bolt, the material that the bolt will be secured into, and the torque that will be applied to the bolt. HEX KEY SIZE 6605 N. Feb 9, 2022 · Learn about the anatomy of a hex head cap screw and how to measure it in this Fastener Basics video! Watch the other Fastener Basics videos: https://youtube. For a 5mm threaded screw, the allen key size is actually 4mm AF and for a 6mm threaded screw the allen key size needed is 5mm. Head Size: The size of the bolt head, usually measured across the flats (the distance between two opposite Drilled head metric hexagon socket head cap screws normally are not available in screw sizes smaller than M3 nor larger than M36. For the bolt length you want to give the length needed from the base of the bolt head to the end of the "shaft" of the bolt. Common SAE sizes range from 1/16 inch to 3/8 inch. Hold onto your Allen key size chart in mm or metric, as using the wrong size Allen key on your hex bolt could easily strip the inside. Jul 20, 2023 · Hex keys, also known as Allen wrenches, are essential tools that come in different sizes to fit specific bolts and screws. Body Diameter (E) Width Across Flats (F) Width Across Corners (G) Head Jul 18, 2017 · How to Figure Out the Size of Screws, Bolts, and Nuts. The following hex bolt size charts should help you to easily select the most suitable product for your requirements. For the perfect, it is important to measure the length of the screw and bolt. Check the fastener or bolt you're working with; it often has a stamped size, especially if it's part of automotive or machinery work. For standard bolts in the range of M5 – M12 we offer our own Pro-bolt Measuring Gauge – see our website for details. Hexagonal (Hex) keys (Allen Keys) and bits sockets are tools which are used to drive screws with a hexagonal socket. 1-1996)Nominal Size or Basic Diameter. The head size of a bolt is important for determining the correct socket or wrench to use. Hex cap screws are typically referred to as bolts and are commonly used in construction and machinery. Internal Threads. To measure the diameter of screws and bolts, you measure the distance from the outer thread on one side to the outer thread on the other side. 3-2003 standard. Bolt Size Measurements. Is that bin of miscellaneous hardware driving you nuts? Let us show you how to easily measure Metric and Standard/American/Imperial bolts with a few simple t Jun 11, 2010 · Step 3 - Measure Length of Bolt. 1/4″ ‐ 20 x 3″ means 1/4″ bolt diameter with 20 threads per inch (TPI) and 3″ length. If you are still struggling to find the correct Allen wrench size for our screw, then you could always measure the size of the screw hole. Length is measured from the point at which the head sits flat with the surface, to the tip of the Sep 12, 2021 · In this video I have explained about various types of Allen key and its use in details. For imperial bolts, count the number of threads in one inch. [Download our printable standard bolt size chart pdf. Some of the commonly used hex screws include hex cap screws, hex tap bolts, and hex machine screws. This size chart focuses on DIN standard 931 bolts (hex bolts which have a Mar 31, 2025 · To measure any other types of round-headed screws that aren’t countersunk, measure from the flat underside of the screw head to the tip. List thread diameter/size, then. This simply means that they are measured from one flat side of the head to the one directly across from it. They come packaged with just about anything that requires assembly too. The diameter of a bolt is the distance across the widest part of the threads. DIN Standard 931 Hex Bolt Size Chart. 2 Measure the width of a thread in mms to get the diameter. For fully threaded bolts, measure the entire length from one end to the other. ”Our MBS Engineering channel is only for education purpose. The size of the socket will indicate which Allen wrench you need. (I. Thread size is one standard size smaller than the shoulder diameter and doesn't need to be specified, except for: Sep 27, 2023 · Fasteners are typically made to the “Nominal” size and wrenches and sockets are made slightly larger to accommodate this. For hex and socket head bolts, measure from under the head to the tip. The measurement technique varies depending on the bolt type. ] Nominal Size or Basic Product Diameter Body Diameter Width Across Flats Width Across Corners Head Height Thread Length | Screws 6 Inches & Shorter Sep 27, 2021 · Measure the Hex Key. If you don't know the size, use a caliper or an adjustable wrench to measure the bolt head's diameter in millimeters. Mar 14, 2025 · Standard Bolt Sizes (US) Our chart provides detailed specifications for standard US hex bolts, helping you select the right bolt size for your project. Then, match it with a wrench close in size, testing fit to ensure it doesn’t wiggle or feel Jul 26, 2021 · Most manufacturers include an Allen key size chart with their products. Jul 16, 2021 · Use our bolt size chart to learn how to measure bolt size and the different dimensions of a bolt. Allen wrenches go by a variety of names (allen keys, hex keys, etc. This is also known as the “major diameter. Jul 25, 2019 · Measure bolt length. Nominal screw sizes M5 and larger have six drilled holes spaced 60 degrees apart unless the purchaser specifies two drilled holes. Measure bolt length from the tip, or bottom, of the bolt to where the shank meets the head. You can also measure from the bottom cavity of the threads from one side to the other to find the minor diameter. If you know how much shorter you want your bolts you should be able to measure that bolt length and subtract to find your new bolt length you need. Measure the bolt length from directly under the hex head to the tip of the bolt. Aug 24, 2023 · Step 3: Measure the Lengths of Bolts To measure the bolt’s length, follow these steps: External Threads Set the bolt down on a flat surface. Choosing the right type of Allen bolt depends on the weight and pressure required, as well as any other mechanical needs you may have. Step 5. ujg npmanfk kzrze fime gqtnp yholm hcaxhsdg rcqo ycxwoe yubtnfyo