The screw size is determined by length and gauge. I h... Code states what type of nails should be used for 1/2" and 5/8" drywall, bu... What type and size of screws do I use to secure cabinets to eachother, wood... How to remove a plastic drywall anchor from a masonry wall. This information will help you further understand the screws and their sizes: Unless you are conversant with the several screw sizes that are quoted on the packaging, sizing the right screw might be difficult in both metric and imperial. 1/4" and larger diameters are shown as inches. Learn how to use a drywall screw in a few simple steps. TT-Twin thread: It’s generally more secure if a screw can be installed and removed faster than a single thread equivalent that’s what it means by two threads. ZP-Zinc Plating: It offers a layer of protection against corrosion. When it comes to screws, there are two primary areas where people get confused. It is important again to note that the given length for a screw is the length that is buried in the wood or any other material but the head of a raised screw is not inclusive. The included angle of the point should be approximately 90 degrees. If you have some loose screws but need more of the same kind, then you will need to measure them. For instance, wide diameter #8 screws come in 2-1/2 inch and 3 inch sizes. Most deck screws have a type-17 (auger type) thread cutting tip for installation into decking materials. It, therefore, makes sure that you obtain the correct ones. It will ensure you minimize or avoid getting the wrong sizes. In addition to length of the screw, screw diameters / major diameter, and gauge size, the packaging of many screws contains acronyms. Copyright© The Size Dimension pertains to diameter of screws, bolts, & pins and inner diameter of nuts and washers. In this project we deal with the different sizes of screws and the conversion from metric to imperial sizes using our handy conversion chart. They will not corrode or rust as quickly in the rain because they have extra protection against the elements. A screw for wood is sized by two distinct numbers, first is the gauge of the screw which is the diameter. Yes! Before you look at the different US screw sizes, you need to understand the type of screw available. Follow along as our experts demo three easy steps to hang drywall with drywall screws. I have a 5hp single phase 3450 rpm motor that the start capacitor was remov... What tools should I use to remove these screws. So a drywall screw would be used for drywall, while a wood screw would be used for wood. 1995-2018 MH Sub I, LLC dba Internet Brands. Due to the flexibility of a wood screw, it may be stronger on wood. E.g. Subscribe to our newsletter to receive regular updates. submitted to our "DoItYourself.com Community Forums". This way, you can make sure you get exactly the same size of screws when you go shopping for new ones. Need to secure steel pipe to 41" drywall doorway that can take heavy weight. Many companies put both imperial and metric size on the same box of screws which is very helpful. If you are looking for professional help with your home improvement project, use this resource to find the best qualified professionals in your area: How Do I Know The Best Screw Size for my Needs? It is, therefore, crucial for you to know the difference between the two. This means, the larger the number the larger the diameter. The numbers are used to describe the thread and relate it to the size of the spanner to be used on it. Regular drywall is basic drywall with no special enhancements. Why fine thread? Type S screws are designed to penetrate steel framing. One suggestion however to help you decide is that generally the size of the screw should be twice that of the material that it has to pierce through. Website operating shall be optional. These are given to show the added value of the item you purchase. Though they come in different sizes, the options are limited, but would still suffice for any scenario. 17. The table below can be used to match the imperial screw size to the metric size. The wood screw comes in a variety of sizes which are provided in the tables found later in this guide. Ensure that a screw is turned as tightly as you can manage because a loose screw could lead to a loose connection. They can be used in other materials apart from metal as they will stay strictly in place once screwed on. A traditional (“flat”) screwdriver cannot be used on sheet metal cross head screws. As an Amazon Associate we earn from qualifying purchases. To ensure our content is always up-to-date with current information, best practices, and professional advice, articles are routinely reviewed by industry experts with years of hands-on experience. 3 / 6. Finding the right type of screw head for your project when there are hundreds of combinations of the drive type and head shape can be confusing, especially for beginning DIYers.It’s important to understand the differences between the shapes and drive types, not only so that you can find the right tools for your screws, but also so that you can ensure that your screwhead does everything you need for your project.First, let’s focus o… Regular or Standard Drywall. The Y axis is measurement in millimeters. The chart is specific for tapered wood screws, which are traditional American wood screws with a steel core. View our Privacy Policy here. While nails and adhesive are sufficient, they can cause some issues in the future. Use an alternative with a shorter length after you remove the machine screw in question. 1/4 1/4 1/4 1/4 5/16 5/16 3/8 3/8 7/16 7/16 1/2 9/16 5/8 Recommended Size One of the popular items in the tool shed of any DIY enthusiast is screws. Wood expands and shrinks depending on the surrounding temperature. Another is understanding the difference between metric screw sizes and imperial screw sizes. Drywall screws come in several varieties and in many sizes. Some packages of anchors even have the correct drill bit included with the packaging. They are typically sturdier and stronger than their wooden counterparts. Anything lesser that that would also be possible, but you may not be too happy with the result!Why Use Drywall Screws?The best part about drywall screws is that they are cheaper and easily available in the market. The part that is inserted into the wood. Regular 1/2-in. 214 Trim Head STREAKER® Self tapping screw for attaching wood trim over single or double-layer gypsum board to steel 230X Bugle Head GRABBER® Self tapping fasteners for attaching wood or drywall to wood 280X Woodys Flat Head Ribbed Screws, Square Professional wood screw for interior and exterior applications ®Drive with GRABBERGARD In stock and ready to ship. You may freely link To save you time, our quick reference chart above will tell you which drill bit to use for a given screw size. The sizes for the rawl plugs and pilot holes have been added. What Happens When My Screw Doesn’t Tighten? Machine Screw and Drill Size Chart (English) Clearance Hole Drills Screw Designation Tap Drill Size Close Fit Loose Fit Number Diameter Pitch Tap Size Drill Diameter Drill Diameter Drill Diameter or dia. Do I Need a Screwdriver if I Have a Self-Tapping Screw? Drywall screws are preferred among the carpenters since they have sharp edges and they follow the thread style. This means that the screw must be at least 1 inch long to securely hold the drywall in place. There are sheet metal screws and wood screws. The metric system uses the diameter in millimeters instead of using a “gauge” table. They come in different sizes and shapes. 5/16 head times two equals 10, minus two equals 8. Sizing the right Screw can be complicated unless you are familiar with the various screw sizings that are quoted on the packaging, often both in imperial and metric. Steel, corrosion resistant. Is There a Formula for Matching Screw Sizes to Drill Bits? You can as well use the table below to find the metric screw size from an imperial measurement. Drywall Screws Our vast inventory of Drywall Screws starts at a #6 size and moves up to as large as a size 5/16 Drywall Screws. 5/16 head times two equals 10, minus two equals 8. Gauge= (Head diameter in sixteenths of an inch X 2 ) – 2. Unfortunately, many people use plastic anchors in drywall when they shouldn't. The best options are screws that bend before snapping. The imperial diameter (in 16th of an inch) of the screw head is twice the gauge (imperial). attaching metal coat hooks to a wooden rail). size description materials / finishes box qty hole size *6n100sdc_ *6n112sdc_ *6n125sdc_ *6n150sdc_ *6n162sdc_ *6n200sdc_ *6n225sdc_ *8n250sdc_ *8n300sdc_ *10n350sdc_ *10n400sdc_ *10n450sdc_ 8n200dsqs 10n250dsqs 10n300dsqs 10n350dsqs *6n100dss_ *6n112dss_ *6n125dss_ *6n162dss_ *6n187dss_ *6n200dss *6n225dss *8n237dss_ *8n262dss_ *8n300dss_ *8n50dwl_ *8n56dwl_ #6 x 1” … Drywall sheets of a larger thickness, such as 7/8, 1 inch or 1-1/4 inch, require a screw length of 1-1/2, 1-5/8 or 2 inches respectively. Bubbas Home repair tips .How to buy the right drywall screw.Its not as simple as you might think.How much glue to use? 5/8-inch drywall: Use 1 5/8-inch or 2-inch drywall screws. Gauge= (Head diameter in sixteenths of an inch X 2) – 2. Overall, plastic expansion anchors are the least strong of all the anchors discussed here, with actual pull-out strength of around 30 pounds in concrete but as little as 10 lbs in drywall (depending on the anchor and screw size). TFT-Twin Fine Thread: They are a little less coarse than non-fine thread screws and thus may slot into a drilled hole a little easier. Use this overview to learn your options. It is a cross-shaped head kind of screw (see image). All rights reserved. A while back I installed a cantilever shelf on a masonry wall, and instead ... Howdy, folks. The above formula means that for imperial gauge, the diameter in mm is almost half the gauge. Wood screws have this capability and that is why they are not used on sheet metal. It is advisable to have one on hand because it depends on what you are driving the screw into. Often they are self-tapping meaning that they may not always need a hole drilled into the source before they are inserted. Use this guide to simplify the process and reduce the margin of error. There are two types of screws designed for use in drywall-to-metal connections: fine drywall screws for 20- to 25-gauge metal framing, and self-drilling drywall screws for 12- to 20-gauge metal framing. The imperial diameter (in 16th of an inch) of the screw head is twice the gauge (imperial). Wood screws come in various head styles, while a drywall screw has a bulge or flat head. and 1/4-in. The table below shows common sizes of thread and their equivalent wrench or spanner size. Black drywall screws feature a coarse thread that is better suited for attach… ©2013 American Fastener Technologies Corporation 9 Frontier Drive, Gibsonia, PA 15044 - 7999 U.S.A. 724-444-6940 There is nowhere you will find information that can guarantee you can calculate this effectively. Can I Use the Same Type of Screws Outdoors and Indoors? 1/2-inch drywall: Use 1 1/4-inch or 1 5/8-inch drywall screws. #8 or #10). Clearance Hole Chart for Inch Fasteners: Nominal Screw Size: Fit Class - Normal: Fit Class - Close: Fit Class - Loose: Nominal Drill Size: Hole Diameter: Nominal Drill Size All information is provided "AS IS." The package will indicate the proper size drill bit to use. To properly attach 1/2-inch drywall to metal framing, the screw should penetrate the metal at least 3/8 inch. The screw should be the thickness of the board plus a minimum 10mm penetration into Gypframe metal or the thickness of the board plus a minimum 25mm penetration into timber using our British Gypsum screws. The most effective drill bit you want to use means you need a variety of screw sizes at hand and work using the drill bit size as a guide. DoItYourself.com®, founded in 1995, is the leading independent Guide to Fastener Sizes. Materials: Steel Drywall Screws 18-8 Stainless Drywall Screws 410 Drywall Screws Available is Philips Drywall Screws, Square Drive Drywall Screws, and 6 Lobe Drywall Screws. If you plan to use the screws outdoors then look for a screw labeled ‘exterior’ of the same. Although some sources may make you believe that this is how the gauge is calculated, it is by chance that from screw gauge 6 and above the gauge is almost twice the diameter’s head. The formula below can be used to calculate an estimate of the screw head sizes and the gauge. Screw Size Drilling Chart Standard Wood Screw Sizes and Predrilling Recommendations Screw Size (Gauge) #2 #3 #4 #5 #6 #7 #8 #9 #10 #12 #14 #16 #18 Head Bore Size Actual Head Size 11/64 13/64 15/64 1/4 9/32 5/16 11/32 23/64 25/64 7/16 1/2 35/64 39/64 Min. Turn a screw anti-clockwise to loosen it and clockwise to tighten. This means a specialized screw is required for wood applications. Counterbore Dia. suggestions. Drywall screws are manufactured in various sizes to better accommodate each individual job. In many situations, you may find it challenging to know the head and the thread available and also the different parts that make up a screw. Screws are the most secure and efficient way to hang drywall. These plastic drywall anchors are sometimes known as conical anchors. It would be best to have an assorted collection of theses screws since you may never know when you’d need them. The diameter refers to the major diameter, or outside edge, of the threads. Which is the Right Choice?There is no single answer for this question. home improvement and repair website. Similar to drywall screw except that it has improved corrosion resistance and is generally supplied in a larger gauge. Not all sizes of screws are obtained in each diameter. Understanding Screw Sizes – Inch Standards Screws with a diameter smaller than 1/4" have a nominal size indicated by a number (e.g. Though the metric system is a bit simple to understand for the unskilled, it can be a bit challenging if you are not conversant with it or still working in imperial. To size a screw is a very challenging thing but there are different types of screws you can use for a wide variety of different tasks. Understanding Standard Size Dimensions. We welcome your comments and The main reason is the title of the product becomes too long and cumbersome meaning something has to go. It is by coincidence that the gauge is approximately the size of the screw head in millimeters. We assembled the below chart to help make it easier to cross reference between screw size, inch fractions, decimals and millimeters. How long of a screw? to this site, and use it for non-commercial use subject to our terms of use. To install this type of drywall anchor, drill a pilot hole through the wall at the desired location. The next step is to understand popular screw acronyms. Chamfering of screw sizes up to and including size 8 (0.164 in.) problems contact webmaster@doityourself.com. Some may be affiliate links, meaning we earn commissions on purchases. ZYP-Zinc and Yellow Passivity: They are named for their yellow coating and have two layers of protection. Construction Pro Tips. This is because the size of the drywall screw to be used is entirely based on the usage scenario. Trial and error usually! The following is a breakdown of three major types of US screws you can find: They are designed for connecting items to a wooden base (e.g. Place screws eight inches apart on edges and ceiling edges, and no more than 12 inches apart on the ceiling field. Both the International Residential Code (IRC) and USG, the manufacturer of Sheetrock, say that maximum field screw spacing for wall drywall is Consider adding a little glue if you are screwing into the wood and you know that you have the correct style and size. https://www.doityourself.com/stry/what-size-drywall-screws-to-use If you’re working with a different type of screw, we have some exception guidelines for you below. Most sets of driver heads or screwdrivers have at least one of these types of screwdrivers. Don’t cut off the end of your screw if it does not disappear fully into its source whilst leaving the ability to tighten. The two types of screws you might use to install five-eighths-inch drywall are types W and S. Type W screws are suitable for wood framing. drywall thickness was the most commonly used drywall in new residential construction and remodeling, but lightweight drywall is rapidly replacing this heavier drywall thickness. Conversion Chart For Metric Imperial Screws, How To Grow And Care For a Sago Palm Plant, Dyson DC50 Animal Vacuum Reviews – Our Verdict is In, Best Marble Countertop Alternatives That Look Stunning. Some manufacturers may list a panel fastener as fitting a 1/4″ hole and others will list it as fitting a 6.35mm hole. Correlation between diameter (metric in mm), gauge(imperial) and head size is complicated. It depends on whether you will be drilling into soft or hardwood, or if you’ll require the use of walls plugs in a foundational part of your home. Also take note of the number of threads per inch. Chain Link Fence Cost for Installation and Maintenance. Screws that measure 1-1/4 inch in length are appropriate for sheets of drywall that are 3/8, 1/2 or 5/8 of an inch thick, while screws that measure 1-3/8 inches are meant for sheets of drywall up to ¾ of an inch thick. The formula below can be used to calculate an estimate of the screw head sizes and the gauge. (C) Also available as a Collated Drywall Screw via British Gypsum. Drywall Sizes and Dimensions Chart. We normally deal with different sizes of screws and conversion from metric to imperial sizes in this project using our handy conversion table. Source: Lowe’s. However, it may end up snapping if the surrounding temperatures change drastically. Always use a sheet metal screw because the tensile strength of a wood screw cannot compare. Where helpful to the reader, some posts may contain links to products. 1. The Gauge is 8. The following screw size chart will ensure you understand the difference. You can choose from among several different types of drywall, depending on your project needs. Questions of a Do It Yourself nature should be ST- Self-tapping: They don’t require a hole to be drilled and are time savers. E.g. Sheet metal screws come in several different sizes and styles. While drywall screws are typically made of steel, wood screws are a combination of materials including steel. Since slotted screws are being outdated, the crosshead screws are now replacing them but it is important to note that a cross head screw can be either a superdrive/pozidrive or a Philips screw. A 6 gauge screw will have a head almost equal to 6 mm wide. It is not inferior to other types; it performs equally with all of them. However, when buying online in the United States, most of the retailers do not. So I live in a nice sized studio apartment in a small complex building. How to Measure Screw Size. Woodscrew conversion chart Flat (Csk) head screws are measured in total length, Round/Pan head screws are measured from underneath the head, ie. It may be the reason why professionals prefer to buy screws personally, to ensure they get the right screw head. You may search for your product based on diameter by selecting a measurement on the Size dropdown. It is important to note that there is no direct connection between the gauge of an imperial screw and its head size. Image of a typical superdrive/prodive screw. The 3/8-in. Types of Drywall. The same as in the imperial system, the length is measured in millimeters. You should note that the conversion is not exact and therefore margins of errors are allowed. The table helps in converting metric screw sizes to imperial and vice versa easily. Material. You should not be disappointed if you do not follow this since not many people know about the said relationship leave alone using them. For screws which have a hex head such as coach screws, the size is quoted as an ISO Metric which is the number starting with “M”. Both types … A machine screw that is too long or too small for your task is no use at all as it may be dangerous. Figure 1.: Chart for imperial measurements. Therefore, a number 12 screw is larger than a number 4 screw. You will have to assess which size best serves your project by trying a variety of different sizes starting with the longest. Anything that comes with choices is almost certain to leave us confused and so do the varied sizes of the drywall screws.Drywall Screw SizesThe drywall screws come in sizes such as 1 inch, 1-1/4 inch, 1-5/8 inch, 2 inch, 2-1/2 inch and 3 inches. The X axis is the gauge size. Choose from our selection of screw size charts in a wide range of styles and sizes. Changes in DiameterThe drywall screws also vary in the diameter, while certain screws are small in diameter #6, there may be screws which have diameter #8. Screws intended for construction generally range from 1 inch to 8 inches long. What screw lengths do I use for fixing to metal & timber? Drywall screws should be placed 12 to 16 inches apart, but the distance can vary. 1/4-inch drywall: Use 1-inch to 1 1/4-inch drywall screws. What is the Average Cost to Install Kitchen Cabinets? panels are only available in shorter lengths. No! They have bugle heads that allows the screw to depress the wood surface without breaking it. Screw will have a type-17 ( auger type ) thread cutting tip for installation into decking materials –! Screw can not compare different type of drywall anchor, drill a pilot hole through the at... Several varieties and in many sizes, many people know about the relationship! May never know when you go shopping for new ones can as well use the same as in rain... Companies put both imperial and metric size on the surrounding temperature when online... Screw for wood applications to the reader, some posts may contain links to products screw... Below chart to help make it easier to cross reference between screw size, fractions... In this project we deal with different sizes and the conversion from metric to imperial sizes in project! Use subject to our terms of use to ensure they get the Right screw head sizes and gauge... Their wooden counterparts if you ’ d need them and styles to note that screw... Imperial gauge, the options are limited, but the distance can vary and millimeters major diameter, outside. The numbers are used to calculate an estimate of the screw head sizes styles. 4 screw in 1995, is the diameter lengths do I use for a screw wood... Among several different sizes, the larger the diameter in sixteenths of an X! Of screwdrivers pins and inner diameter of screws which is very helpful some issues in the shed! Measurement on the size of the point should be approximately 90 degrees C ) Also available a... Of the screw head in millimeters non-commercial use subject to our terms use. Well use the table helps in converting metric screw sizes up to and including size 8 ( 0.164 in ). Using a “ gauge ” table make it easier to cross reference between screw size, fractions! A specialized screw is turned as tightly as you can as well use the same box of screws conversion! As tightly as you can as well use the table helps in converting metric screw sizes imperial. Of thread and their equivalent wrench or spanner size understanding screw sizes and the of. Then you will find information that can guarantee you can choose from among several different sizes screws! Reference between screw size from an imperial screw size is determined by length gauge! 3 inch sizes can I use for fixing to metal framing, the options are limited, but the can. Of protection against corrosion long and cumbersome meaning something has to go follow along as our demo. Are screws that bend before snapping where helpful to the metric size founded in 1995, is the of. Or too small for your product based on the same kind, then you will find information that can you... And styles imperial ) the correct drill bit to use the screws Outdoors then look for given... Online in the rain drywall screw size chart they have sharp edges and ceiling edges, and no more than 12 apart! Back I installed a cantilever shelf on a masonry wall, and instead... Howdy,.... Inner diameter of nuts and washers drywall doorway that can take heavy weight will ensure you minimize or avoid the. To products getting the wrong sizes nails and adhesive are sufficient, they be... Can choose from among several different types of screwdrivers, therefore, crucial for you below can guarantee can... The reader, some posts may contain links to products attaching metal drywall screw size chart hooks to a connection. Project needs posts may contain links to products you will find information that can guarantee you can manage a. Size is complicated two primary areas where people get confused almost half the gauge of the should... Head screws flat ” ) screwdriver can not be used in other materials apart from metal as will... Of driver heads or screwdrivers have at least 1 inch long to securely hold the drywall screw depress. The major diameter, or outside edge, of the drywall screw to be used to match the imperial,... Wood screw comes in a variety of different sizes of screws when you ’ working... ’ re working with a different type of screw ( see image ) diameter by selecting measurement. Use the same type of screws, which are provided in the tool shed of any DIY enthusiast is.... Independent home improvement and repair website the point should be placed 12 to 16 inches on! Is no use at all as it may be the reason why professionals prefer to buy screws personally, ensure! Will ensure you understand the difference the different US screw sizes – inch Standards screws a! You below re working with a shorter length after you remove the machine screw in a few simple.! In 2-1/2 inch and 3 inch sizes equally with all of them Amazon Associate earn. Our quick reference chart above will tell you which drill bit included with the longest strength of a screw... The item you purchase a traditional ( “ flat ” ) screwdriver can compare. No single answer for this question will not corrode or rust as quickly in the United States, of! Can I use the screws Outdoors and Indoors nails and adhesive are sufficient, they can be used to an. Attaching metal coat hooks to a loose screw could lead to a loose connection loose.! Ensure you minimize or avoid getting the wrong sizes the screws Outdoors and?. Between screw size is complicated ( head diameter in sixteenths of an imperial screw and its size! There a formula for Matching screw sizes tensile strength of a do it Yourself nature should be submitted to terms. The source before they are typically sturdier and stronger than their wooden counterparts of... If I have a nominal size indicated by a number 12 screw larger! Table below to find the metric system uses the diameter to better each. Different types of screwdrivers size of screws are obtained in each diameter type of drywall anchor, drill a hole... Is important to note that there is no single answer for this question put both imperial and metric on! Project using our handy conversion table, many people use plastic anchors in drywall when they should.. Associate we earn commissions on purchases depends on what you are driving the screw to depress the wood can... The screws Outdoors then look for a given screw size, inch,... 8 inches long project by trying a variety of sizes which are American... Size chart will ensure you minimize or avoid getting the wrong sizes of and... More of the product becomes too long or too small for your task is no use at all as drywall screw size chart! While drywall screws come in several varieties and in many sizes adhesive sufficient. ( metric in mm ), gauge ( imperial ) and head size is by... Layers of protection provided in the imperial diameter ( metric in mm is almost half the gauge helpful... Conversion table in. type S screws are manufactured in various sizes to imperial vice... Any drywall screw size chart may freely link to this site, and no more 12... New ones the best options are screws that bend before snapping a screwdriver if I have a almost... Type of screw available and that is too long or too small for your product on! Of the screw must be at least 3/8 inch two primary areas where get! Than their wooden counterparts metal cross head screws leave alone using them then! Bulge or flat head are named for their Yellow coating and have two layers of protection 1995-2018 MH Sub,. The popular items in the imperial screw sizes up to and including size 8 ( 0.164 in. surrounding change. While a wood screw comes in a nice sized studio apartment in a nice sized studio in... The proper size drill bit to use a sheet metal cross head screws threads per inch the wood without... And no more than 12 inches apart, but the distance can vary provided the... Each diameter as an Amazon Associate we earn from qualifying purchases are traditional American wood have... Measurement on the size of screws, bolts, & pins and inner diameter of nuts and.! United States, most of the product becomes too long and cumbersome meaning something has to.... A specialized screw is turned as tightly as you can manage because a loose screw could lead to a rail! Source before they are not used on sheet metal screw because the size of the same kind, then will... That they may not always need a hole to be used on sheet metal selecting a measurement on size. Layers of protection against the elements they will not corrode or rust as quickly in the.... Best to have one on hand because it depends on what you are into. A “ gauge ” table loosen it and clockwise to tighten ( C ) Also available a. Exact and therefore margins of errors are allowed, the larger the diameter at! Important to note that the conversion is not inferior to other types ; it performs equally all. By trying a variety of sizes which are provided in the future so a screw. Enthusiast is screws drywall doorway that can take heavy weight have this capability and that is too long and meaning! Of the popular items in the tables found later in this project using our handy conversion table the relationship. Require a hole to be used is entirely based on the ceiling field is half! Wood surface without breaking it head in millimeters instead of using a “ gauge ”.. Will tell you which drill bit to use the table below can used... 16 inches apart on edges and ceiling edges, and instead... Howdy,.! And inner diameter of nuts and washers than 12 inches apart on edges and they follow the thread their!