Use a digital caliper or micrometer: Digital calipers and micrometers are more precise measuring instruments that can give you an even more accurate measurement of bolt head size. Instead of using gauges in expressing diameter, the metric system uses millimeters. In this article, well go through a complete guide of bolts, which involves bolts definition, types, dimensions explain, and the standard bolt sizes chart in metric and imperial. Sponsored . There are two different methods of sizing wrenches - the standard method (SAE) and the metric sizing. Metric Bolt Specification We refer to metric bolts using 'M' sizes followed by the diameter, thread pitch, and length. The first step in measuring the length is finding a surface to lay it down on an even surface. You dont always measure from the top of the head. When measuring the length of a flathead screw, start on top of the head down to the stem. Now that youve got the terminology out of the way, you can look at bolt size charts with more ease. It will not waste your time. The next clue narrows things down for us. For example, 4.0 means the screw has a diameter of 4 millimeters (mm). Bolts can me specified in metric using millimeters, but the standard, internationally-recognized descriptions of bolt sizes are in inches. Say, youve drilled a 33/64 inches hole, then 33 divided 64 is 0.515625 inches. | Based on star rating and number of customer ratings, Nut and Bolt Thread Checker (Inch & Metric) Nut and Bolt Size Gauge- 14 Inch & 12 Metric New Individually Assembled Thread Gauge Suitable for Detecting Fixed Bolts or Threaded Holes in Enclosed Areas, [Patent]CKE Upgraded Nut & Bolt Thread Checker (Inch & Metric) Detachable Wire Loop Design - 44 Male/Female Gauges - Inch & Metric Detachable Nut and Bolt Thread Size Checker Identifier Gauges, Giwaelro Nut and Bolt Thread Checker - 26 PCS Screw Size and Bolt Size Thread Gauges - 14 Inch & 12 Metric, 5 Pcs Thread Pitch Gauges Measure Tool Set,Stainless Steel Thread Gauges 3 Pcs 55 & 60 Degree Metric System Centre Gage + 51Pcs America SAE Type + 52 Pcs Metric & America SAE Type & British Whitworth, Marine Bolt Supply Nut, Bolt & Screw Gauge (Standard & Metric) (Coarse & Fine) Diameter, Length & Thread Pitch (Green), CKE Nut & Bolt Thread Checker (Inch & Metric) - 26 Male/Female Gauges - 14 Inch & 12 Metric, 3765 Piece Grade 8 USS Nut Bolt Washer Assortment, Hex Head Cap Screws, Flat and Lock Washers Coarse Thread, EAWONGEE NutandBoltThreadChecker, Inch & Metric Thread Gauge, Nut and BoltSizeGauge- 14 Inch & 12 Metric, AETTL 660 Piece Machine Screws Assortment Kit, M6 M5 M4 M3 Nuts and Bolts Assortment Kit, Stainless Steel Metric Assorted Machine Screws Set Allen Wrenches Hex Socket Head with Flat Washers, Nut & Bolt Thread Checker - 26 Male/Female Gauges - 14 Inch & 12 Metric for Quickly Checking Nuts and Bolts Inch or Metric and Verifying The Size, Screw Chekr SAE/ Inch Screw Thread Size Gauge (No. Usually, the metric holes are in the top row and the standard holes are in the bottom row. The closer distance between these threads allows a tight hold. IMPORTANT SCREWS LINKS :Pdf:Dimensions:Faq. It has a pitch thread of 1.00mm for fine and 1.25mm for standard. The chart below shows metric bolt conversions and DIN numbers for fasteners. Because of their great holding strength, bolts have a broad range of use compared to other fasteners. That said, its common to see abbreviated metric bolt formats, such as M14-50. It is recorded in a decimal point of an mm. Pitch diameter: The diameter where the thread thickness = the space between threads. These selected sizes are recommended also for general engineering use. For example, an M3 bolt with a medium fit would have a 3.4 mm clearance hole. The M5 screw size has a diameter of 1/8 inch. On the other hand, bolt torque size charts have many variables and different measurements for each bolt grade/class. The resulting number will be the size of the wrench you need to adjust the bolt properly. Structural wood ones may appear similar to wooden ones, but they are more durable. M3 bolt = 5.5 mm M4 bolt = 7 mm M5 bolt = 8 mm M6 bolt = 10 mm (most common small engine bolt size) M7 bolt = 11 mm M8 bolt = 13 mm (very common bolt size) M9 bolt = 17 mm (very common bolt size) M10 bolt = 19 mm M12 bolt = 22 mm Gauge = (Head diameter in sixteenths of an inch X 2) 2. Choose from our selection of metric U-bolts, including over 850 products in a wide range of styles and sizes. It doesnt matter if youre working outside or on furniture. THREAD (BOLT THREADS) A raised, helical rib or ridge around the interior or exterior of a cylindrically shaped object. The thread pitch is the distance between threads expressed in millimetres (measured along the length of the fastener). What about using a metric bolt size chart? Use millimeters to measure from one side of a thread to the other. Other types are used for drywall and concrete. Metric Nuts. In general, smaller fasteners have finer threads, so the thread count is higher. If they are, you may have the wrong size of bolt. Metric Hex Bolt Dimensions | Atlanta Rod and Manufacturing | Manufacturing of Bolts, Concrete Embeds, Construction Fasteners, and Stainless Steel Bolts - Atlanta Rod and Manufacturing Common metric dimensions for hex bolts from Atlant Rod. An M4 screw is slightly larger than an M2. To put it simply, this is where the oval top would rest on the surface. All your fastener needs from a single source Aspen Fasteners 4807 Rockside Road, Suite 400, Independence, OH 44131 USA www.aspenfasteners.com | aspensales@aspenfasteners.com | 1-800-479-0056 This table shows how to determine the clearance hole size for a bolt. There are also machine bolts with a fully threaded shaft and a semi-cone point, used to fasten wood to wood, wood to metal, and metal to metal. A wood screw has a pointed tip that aids in wood-to-wood fastening. The good news is that you can now confidently say that you know all about bolts and bolt size charts. You can screw bolts on anything from drywall, metal, wood, to steel. 27 Size Measurements, Measures Thread Sizes, Bolt Lengths in Both inches & Metric Sizes. These bolts are usually made from quenched and tempered medium carbon alloy steel, so they can withstand a tremendous amount of pressure. Metric bolts are available with either coarse or fine thread pitches. 1/4 Drive. Whats the thread pitch? . Metric & standard bolt screw sizes are determined by length and thread count. Always refer to project specifications and consult an engineer to ensure that your application is appropriate. Do keep note drywall ones cannot support tile and cement board. However, metric bolt head size is measured in millimeters. The measurement of an inch nut or bolt will be listed as the thread size a number between one and 12 or an inch increment followed by the threads per inch (TPI). Decimal . Definitions of terms are located below the chart. First, look at the chart and find bolts that have a half-inch diameter. Depending on the application, they come in different forms and sizes. Then, read the measurement on the calipers scale. It happens, its frustrating, its time-consuming, I get it. Add to that the difficulty of deciphering all of the figures and terms in a bolt size chart, which is nothing short of excruciating. This is why we give the book . To take advantage of the convenience these fasteners offer, you need to match them accordingly based on their sizes. When looking into and determining screw size dimensions, there are two things you need to understand the length and the thread count. A #1 gauge is 5/64 inch, and a #2 gauge is 3/32 inch. The size of a metric bolt is specified using pitch, diameter, and length in millimeters. The answer to this question depends on what the bolts will be used on. It most likely looks the same for all bolt types. If you do see what you are looking, we would love to assist you and give you a quote today! Hex head ones are an exception to this rule, which means you need to measure from the bottom of the head. Youll most likely use coarse threaded bolts, which have a lower thread count. We typically use the threads mentioned above in rack applications. These marks are radial lines; the more lines on the bolt, the greater its strength. Bolt head size charts are used as a reference guide to help users select the appropriate size of bolt head for a given application. According to their construction, eyebolts can be classified as the forged and bent eye. If you want to convert millimeters to inches, you can either divide the figure by 25.4 or multiply it by 0.0394. From this number, you can gather a lot of information. Remember that the standard bolt size equivalent is an approximation, not a direct equivalence. If the bolt body is the same for all bolt types, then the head is the complete opposite. The bolt body has three dimensions that are essential to any bolt size chart: bolt diameter and thread pitch. Several people assume that these two materials are the same, but they are different. If there are four thread gaps in a one-inch length, the thread pitch would be 0.250 inches (one inch / 4 thread gaps = 0.250 inches). The screw is usually inserted into an existing threaded hole or pass through the material to form its own internal thread, and then it is tightened by applying torque to head. The bolt chart provides both US and metric stud sizes. A bolt head size chart is a tool that provides a visual representation of the different sizes of bolt heads, typically showing the size of the bolt head in both imperial and metric units. More Recent 'Small Engine' Topics on LR Fix, M6 bolt = 10 mm (most common small engine bolt size). Physically, they look similar. Machine bolts can be divided into hex bolts and square bolts based on the head type. Several kinds of bolts exist, which include Hex bolts, J bolts, T bolts, Anchor bolts, and Flange bolts. The thread pitch is the distance between each thread in mm. Our metric stud bolt to nut table is meant to help determine the correct size bolt or nut for your purpose. Shank Length Fastener length is measured from where the material surface is assumed to be, to the end of the fastener. ISO metric screw thread: The ISO metric screw thread is a standardized screw thread system that is widely used around the world. It specifies the dimensions and tolerances for both metric and imperial bolt head sizes, as well as the corresponding wrench sizes and other details. Also, you need to show them which standard . In fact, the bolt diameter is a little smaller and the nut diameter a little larger. A gauge number or fraction of an inch represents the diameter in the imperial system. Use a bolt gauge: A bolt gauge is a tool specifically designed for measuring bolt head size. Handbook of Bolts and Bolted Joints - John Bickford 1998-04-28 Presenting time-tested standard as well as reliable emerging knowledge on threaded fasteners and joints, this book covers how to select parts and materials, predict behavior, control assembly processes, and solve on-the-job problems. Metric bolt sizes are available in a range of diameters, from as small as 2mm to as large as 100mm or more. Whatever the case may be, our wrench conversion chart will give you the best-fitting standard or metric wrench for a given bolt size. The first column contains bolt grades (standard) or classes (metric). (Nominal diameter is more of a label than a size. This International Standard specifies selected sizes for screws, bolts and nuts in the diameter range from 1 mm to 64 mm of ISO general purpose metric screw threads (M) having basic profile according to ISO 68-1. The SAE to metric conversion size chart below is the easiest way to convert standard & inch measurements to mm & cm. Well, if you know a holes size in inches, but youre using a metric bolt, youll need to do some calculations. The coating prevents corrosion from happening as a result of mortar and moisture. A bolt size chart describes its size based on its proportions. Nearest . Class Grade Sizes (mm) Mini. For the most part, however, the metric charts have columns that list the equivalent or approximate sizes to the standard bolt sizes. No need to worry, though, because these are clues that you can work with. For flat-headed ones that are countersunk, measure from the tip to the top of the head. Diameter/Decimal/Metric Chart for Small Diameter Fasteners Fastener Conversion Chart ANSI B1.13M, also identified as ASME B1.13M, defines the standard for metric screw threads in American units with metric units in parenthesis. TPI stands for Threads Per Inch, which means the total number of threads per inch measured along the length of a fastener. The greater the pitch on metric fasteners, the more distance between threads. For some time, the imperial system had been the standard measurement system. This column is to help you quickly find the equivalent or approximation of metric bolts. This isnt the only thing thats different, though! Tightening Torques - Recommended bolt torques. Coarse pitch threads are preferred and should be used whenever possible, as stated in ASME B1.13M. In the standard size chart, the bolts are labeled as fractions, which happen to be the bolts diameters. Then, measure the distance from the center of the bolt head to the farthest point on the bolt head. Why is this math lesson necessary, you say. Understanding Inch & Metric Thread Callouts. Thats why we have an additional column in the metric chart below: the Standard Inch Equivalent. To measure screw size, we take its diameter. The defined diameter of metric bolts is actually slightly larger than the actual diameter. So an M8 bolt would have a diameter thats slightly under 8mm. Ignition Coil Resistance Chart For 2-Stroke and 4-Stroke Small Engines. Flange Bolt Dimensions Chart and Stud Size in mm Flange Bolt Dimensions Chart and Stud Size in mm In this article, I have covered Flange Bolt Dimension Chart and Stud Size Dimensions for stud and bolt used in piping. In the standard chart, a bolts tensile strength is represented as grade radial marks on top of the bolts head. No inquiry is too large or too small, we specialize in locating hard to find items. Here is an example of how metric sizing: M10-1.0 x 20 Taking a closer l A bolt size chart describes its size based on its proportions. The second chart below is a US fraction to metric mm for the more common sizes up to 4". Carriage bolts are usually used to fasten metal to metal or metal to wood. Here's an example of a metric bolt specification: M5-1.0 x 20. The M corresponds to the outer diameter in the metric system, so an M2 has a diameter of 2mm. Quenched and tempered low carbon boron steel, Quenched and tempered medium carbon alloy steel with additives, Quenched and tempered medium carbon steel or carbon steel with additives, Quenched and tempered medium carbon steel, Quenched and tempered low or medium carbon steel, M shows that the bolt uses metric thread, 5 is the bolt shanks nominal diameter in millimeters, 1.0 refers to the thread pitch in millimeters, 20 is the overall length in millimeters, About 0.35 inches of space to keep the bolt flush to the material, Hot-dipped galvanized steel; suitable for outdoor use, Chrome or nickel-plated steel; can be used outdoors, Bronze or brass; expensive and more common in decorative and art pieces. The length of the bolt is also expressed in millimeters and can vary based on the specific needs of the application. Metric Bolt Sizes Metric nuts and bolts are commonly referenced using 'M' sizes, for example: M3, M8, M12. A Nut is the counterpart of the Bolt and it is hexagonal (sometimes square) object with threads on the inside. But it is easier to specify the components by a single size designation since the bolt and nut are mating components.). A2 and A4 Stainless: This is the class of metric bolts with the A2 and A4 stainless quenched and tempered steel material. One millimeter is the equivalent of 3/64 of an inch, so you can get pretty exact! This calculation and conversion factor is valid for either metric or standard bolt sizes. " Drive. What is the significance of knowing these things if you can walk into the hardware store and ask the sales clerk for assistance? By the late 20th century, several countries have adopted the metric system. See Our Other FREE Downloadable Resources In standard bolt size charts, the thread pitch is the number of threads in one inch. Again, you find that bolts 1/2 and 9/16 have a head height of around 0.35 inches, with a minimum of 0.302 inches and a maximum of 0.371 inches. Sometimes, they do not know much about it. In the metric system, its class is indicated via a class number that is imprinted on the bolt head. The M5s dimensions are significantly thicker than an M4 but can be used in several applications. Pitch combinations that seem to be in the middle can simply be described as fine pitch. The bolt head size is often only used to determine the wrench to use when tightening or loosening the bolt. You can even use it on concrete. Just invest little mature to right to use this on- The advantage of the metric system is that you can get accurate measurements down to the very smallest increments. The M12 is even wider and can shoulder heavier loads. THREADS PER INCH The decimal equivalent of the number of threads in an inch. You will want the entire thing to lay flat, which means the head will need to lie off of the edge of a table or other surface. Strength ratings are as follows- Proof load (max non-deformation): 55,000 psi (33,000 for -1.5") Metric Imperial; Millimetres (mm) If the measurement reads M2 x 8, the diameter is 2mm and has a length of 8mm. Part of what makes bolt size charts difficult to read is not knowing what the words and numbers mean. Because this is approximately the same as the Major or Thread diameter the thread diameter measurement can be used for fully threaded bolts. All units in mm. They can be helpful in determining the size of a bolt head when only the bolt is available. Whether youre a DIY enthusiast, an engineering student, or an experienced machinist, youre probably aware of how much more sturdy your project can be with the right bolts. Hex bolts are designed with a hexagonal head that to be driven by a wrench and external machine threads, maybe partially threaded or fully threaded. Once you have these values, you can now divide the length by the number of thread gaps. Metric fasteners are measured by length and pitch, or the distance between threads. A U-bolt would be described by the size of the pipe it is clamping. The M2 screw size has a diameter of 1/16 inch. Take the diameter of the bolt, and multiply by 1.5. The shank has no threads. ASME is the organization that is in charge of a lot of the standardization work. And for our international readers, you likely have more metric wrenches in yours. Download the Metric Clearance Hole Chart to save the chart as a PDF - useful to print out to have next to your tools. You can use the same method to read a metric chart, but keep in mind that all measurements are in millimeters. That figure also refers to the bolts diameter. Using the wrong thread pitch may result in a damaged bolt or, worse, a damaged small engine block. Width of nut across flats These thread sizes and classes represent bolts and screws, as well, as other standard external threads. 19mm. Where we also manufacture Square Drive Pan Head Machine Screws, SS Machine Screw and Stainless Steel Metric Machine Screw for industries like Oil & Gas, Petrochemicals, Refineries, Thermal, Nuclear sector, Solar Power Plants, Atomic Energy, Defense and Aerospace etc. Bolt size is measured across the head of hex and square bolts, from flat side to flat side, just like Standard bolts. All units in inches. You tend to find three standard sizes, although there are others available. We use a lag screw to fasten components that handle a heavy load. US and Metric Fasteners - Thread Sizes - Printable fastener chart. If you often do DIY, one of the popular items you are using is screws. To calculate the gauge and head sizes, you can use the formula below. Raaj Sagar Steels is an international supplier of Slotted Machine Screws, Spanner (Snake Eye) Machine Screws, Stainless Steel Lag Screws, Torx Machine Screws, Trim Head Hex Cap Screws, Stainless Steel Wood Screw, One Way Machine Screws.The Screws manufactured in Stainless Steel and Duplex steel, we also manufacture Phillips Machine Screws at our other factory in Vapi, Gujarat. They are made of low to medium grade carbon steel, the head has no markings. It allows you to drill directly into the surface without pre-drilling. If you work with small engines long enough, you will eventually encounter a broken or missing bolt. There is also the Allen drive, which has a six-sided socket. Thread Pitch Still, there are some oddly shaped bolts out there. In the second column, you have the bolt diameter in decimals or whole numbers. Finding the correct size can be a daunting task if you dont know the imperial or metric system. Its length is measured from its tip to the point where its shank meets the head. 8mm falls in between and converts to a 5/16 or 11/32 standard. Below is a table common fastener sizes and lengths and their US (Inch) decimal and closest fraction equivalent. Try Fastener Dimension Guide now. ANSI B18.8.2 Metric . TPI is used only with American fasteners. In general, the first thing that you should do is consider whether youre using a bolt thats shorter or longer than 6 inches. When you get into the smaller dia sizes the pitch goes pretty small. Thread pitch refers to how tightly the thread of a bolt goes around the bolt shaft. Bolt Head A bolt's head is can be round, hexagonal, or square in shape. Working out which of the variously sized and shaped bolts in front of you is the one you need can be quite daunting. Metric Bolt Size Chart Thread Pitch Conclusion Introduction to Bolts, Nuts and Washers A Bolt is a cylindrical object with a hexagonal (sometimes square) head on one end and threads (fully or partially) on the other end. Length is measured from under the head to the end of the bolt Note: Head sizes may dier from what is shown due to dierences between metric standards Length 16mm 12mm 8mm 7mm 6mm 5mm 4mm 3mm 10mm 14mm Coarse thread . They come in several types and sizes, which you can use in metal and wood. The length of a metric bolt is measured and defined in exactly the same way as imperial bolts (fasteners). Metric bolts, however, have super fine thread pitchgranted that only bolts M10 and M12 have super fine thread pitch options. Similar to the size charts, the tensile strength charts are predominantly the same, but with different measurement units. Push the bolt into the holes on the gauge and find the smallest hole the bolt will fit into. Lag bolt size charts, however, have one extra column for Shoulder Length. Metric nut comparison. Anchor bolts come in different types based on the installation method. Call us 850.764.BOLT (2658) Sales@MonsterBolts.com. For custom products in a specific application, Online CNC design also serve your needs. Brass, nylon, stainless steel, steel, aluminum, and titanium are a few of the materials used in fabricating this type. It specifies the dimensions and tolerances for imperial bolt head sizes, as well as the corresponding wrench sizes and other details. If the bolt has threads, the threaded area is also included in this measurement. Do not use these values for standard metric internal thread design. Metric US Decimal Closest* The size of a metric bolt is specified using pitch, diameter, and length in millimeters. The diameter in the imperial system is represented in either fraction of an inch or a gauge number. Let's Fix! Shoulder boltShoulder bolts, also known as shoulder screws or stripper bolts, are a type of machine screws that consist of three sections, the long cylindrical non-threaded shoulder is between the head and threads, which allows the attached part to rotate around or slide along its length. We also have a resource on Phillips head options. Thread pitch and thread spacing mean the same thing, so dont get those two confused. english/ metric bolt substitution table equivalent metric bolt substitution - astm grade bolt sizes f - 568 class 4.6 f - 568 class 8.8 f - 588 class 8.8.3 . G. Mahimtura Marg, 3rd Kumbharwada, Mumbai-400 004 (India) City: Mumbai-400 004, India Phone: +91-22-6659 5285 , 6639 4214 Email: info@raajsagarsteels.com Website: www.raajsagarsteels.com key personnel Contact Person: Mr. Milap Mehta Cell: +91-9869 532 584, Uae , vietnam, qatar, Saudi Arabia, italy, thailand , bangladesh, philippines, Pakistan, Trinidad Tobago, Sri Lanka, Bahrain , sri lanka, kuwait, chennai, bangladesh, Sri Lanka , Saudi Arabia, Bangladesh, singapore, india, philippines , oman, Copyright 2017 Raaj Sagar Steels| All Rights Reserved | Website designed & SEO by, Metric Bolt Conversion | Fastener Conversion Chart, Coarse thread pitch partially threaded (specify grade), Coarse thread pitch fully threaded (specify grade), Fine thread pitch partially threaded (specify grade), Fine thread pitch fully threaded (specify grade), Nylon insert locknuts (specify pitch and class), All metal locknuts (specify pitch and class), Socket head capscrews (normally GR 12.9 and coarse thread), Flat head socket capscrews (normally GR 12.9 and coarse thread), Socket setscrews (normally GR 12.9 and coarse thread), All threaded rod (normally 1 meter lengths, specify grade and pitch), Fastener Chart | Metric Bolt Conversion | Common DIN Numbers for Metric Fasteners | Diameter/Decimal/Metric Chart for Small Diameter Fasteners. They can ensure a reliable, long-lasting connection between two sections of a large and enclosed area. If the measurement says 1/4-20, it means it has a diameter of 1/4 inch and 20 threads per inch. An M8 screw has a diameter of 8mm. Thats half a mm between the crest of each thread. The term grade is used in the imperial system, while class is used in the metric system. These grade marks are given depending on how many pounds per square inch (PSI) the bolt can hold. Well, there is not always someone available to assist you. Bolts and screws are integral parts of fastening or putting together things. Metric bolts with a coarse thread pitch have more threads per inch than comparable imperial bolts. A bolts head is can be round, hexagonal, or square in shape. Some sex bolts have knurled barrels to allow one-sided assembly. So, next time youre working on a project, you can acquire the bolt dimensions that you need easily. A ruler is all you need to determine thread count and size. This kind of bolt can create its own thread and form friction joint in wood with their coarse threads and other soft materials when tightened, they dont need nuts, usually used to connect heavy lumber or other heavy materials that are bearing an intense load. ANSI B1.13M, also identified as ASME B1.13M, defines the standard for metric screw threads in American units with metric units in parenthesis. Note - Metric screw diameters usually start with "M" (M3, M4, M5. Fine-threaded screws are best used with pre-tapped holes. The diameter and length of the stud and bolt are covered in flange standard ASME B16.5 & B16.47. Phillips and slotted drives are the two main types. In summary, diameter is listed first before the length. Lastly, you need to measure the distance from one thread to another. " Drive. Hex bolts can be used for infrastructure that requires a strong fastener with high tensile strength properties, they can also be used in tight spaces with limited access because tools can access them from all angles, or fastening wood, steel, or other materials in bridges, buildings, and more construction projects. Now that you know how to take the measurement, the next step is to place the ruler down the axis to get the thread count. Standard bolt sizes chart pdf The metric system requires new fastener sizes, new material stock sizes, new cutting tools, new gages, etc., to be used in production. Anchor boltWith a threaded part in one end and non-threaded in another end, which can be made in L shape, Pin type, Wedge type, or other forms, often work with steel plates or stiffeners to connect structural and non-structural elements to the concrete, transfer tension forces and shear forces. For round-headed ones, measure from the tip to the bottom of the head. Deck screws are for fencing and decks, but they can also be used for similar outdoor projects. Generally, the metric system is easier to understand. However, here's a quick overview from the chart: The M2 screw size has a diameter of 1/16 inch. US to Metric Conversion Table Print this page . There are actually up to four pitch . Download the Imperial Clearance Hole Chart to save the chart as a PDF - useful to print out to have next to your tools.. Want to determine what size clearance hole for Metric, for example, a 10.5 mm clearance hole is required for an M10 close fit, then check out our chart here.