What sets these apart, however, is that all sizes are also color-coded for easy reference. Unlike other driver measuring systems, the same numbers on a Torx screwdriver apply to both SAE and metric scales. I have been looking everywhere with no success either! Now that the original patents and licensing restrictions have begun to expire, Robertson screws are gaining in popularity worldwide. Product Overview The Husky 8-in-1 Torx Screwdriver Set includes a screwdriver, spinning removable cap for bit storage and 4 double-sided bits with T4, T5, T6, T7, T8, T9, T10 and T15 Torx hex tip sizes. www.wihatools.ca. Common marking: T. Torx Tamper-proof Torx is a relatively new type of bolt that was designed in 1967. But how do you know when you have all the necessary sizes? By some manufacturers and resellers head sizes are also … A Subsidiary of Wiha Werkzeuge Gmbh Schonach Germany. Torx drives use a numbering system based upon the distance between two opposing points. I wish you the best. I appreciate your site as I am trying to make up a set of as many complete sets of drivers complete with individual handles permanently attached as a gift for my son. What other wood screw sizes will fit the opening of a Robertson Screw that would need a #1 screwdriver? What a fantastic gift idea for your son. This has made them quite popular in both electronics and automotive industries. $ 6 99. This set features a versatile assortment of 5 tip sizes, high-quality and … The 2.0 is the diameter and 8 is the length (both in mm). Measurements for hex keys is done via AF (short for across flats). Bosch made one type P2R2 bits, its not double ended bit, but one bit fit both PH2 and your beloved RED 2. PicoFinish Precision Slotted Screwdrivers, PicoFinish Precision Phillips Screwdrivers, PicoFinish Pentalobe and Y000 Precision Screwdrivers, System 6 Drive-Loc Adjustable Length Screwdrivers, System 6 Drive-Loc Slotted and Phillips Blades, System 6 Drive-Loc Square and PoziDriv Blades, System 6 Drive-Loc Tri-Wing and Torq Set Blades, Bit Holding Socket Replacements and Adapters, 26-in-1 Ultra Driver Multi-Bit Screwdrivers, 26-in-1 Ultra Driver Double Ended Replacement Bits, 26-in-1 Ultra Driver Double Ended Bit Reload Packs, 12-in-1 Ultra Driver Multi-Bit Screwdrivers, 6-in-1 Ultra Driver Multi-Bit Screwdrivers, 6-in-1 Stubby Ultra Driver Multi-Bit Screwdrivers, Insulated Ultra Driver Multi-Bit Screwdrivers, Insulated Belt Pack Pliers and Screwdrivers Pouch Sets, Insulated Pliers and Screwdrivers Tray Sets, Insulated Pliers and Drivers Carrying Case Sets, Insulated PicoFinish Precision Screwdrivers, Insulated Variable Torque Limiting Screwdrivers, Insulated Slotted and Phillips screwdrivers, Insulated SlimLine Blade and Handle Screwdriver Sets, Insulated SlimLine Pop-Up Handle and Blades Sets, Soft Grip Adjustable and Waterpump Pliers, Industrial Insulated Roll Out Pliers Sets, Industrial Insulated Stripping and Crimping Pliers, Insulated Torque Limiting Screwdriver Sets, Insulated Torque Slimline Blades for Torque Limiting Handles, System 4 Precision Micro Blades and Handles, SYSTEM 4 Precision Micro Bits and Handles, Ball-End Hex Long Arm Black Finish L-Keys, Ball-End Hex Mid-Length Black Finish L-Keys, Ball-End Hex Short Arm Black Finish L-Keys, Ball-End Hex Soft Grip Chrome Finish T-Handles, Ball-End Hex Soft Grip Black Finish T-Handles, 1/4" Square Drive Hex Bit Socket Sets on Molded Rails, 3/8" Square Hex Bit Socket Sets on Molded Rails, ESD Safe Compact Technicians Micro Bit Sets, ESD Safe Interchangeable Screwdriver Blades in Steel Boxes, ESD Safe Interchangeable Screwdriver Blade Sets, ESD Safe Precision Interchangeable Screwdriver Blade Sets, ESD Safe Precision Screwdriver Pouch Sets, ESD Safe Precision Master Precision Screwdriver Sets, ESD Safe Precision TorxPlus® Screwdrivers, Drive-Loc Adjustable & Interchangeable Blades, Security Torx Socket Sets on Molded Rails, Typical Dimensional & Torque Specifications of TORX Tools. T6 & T8 are the most common size and PH0 and PH1 are the most common for philips. You can identify the size required for a random screw by measuring the width of the slot and comparing it to a Torx sizing chart. 5-Piece Klein Tools 19555. JavaScript seems to be disabled in your browser. The Wiha Torx screwdrivers have hardened, precision black tips and are made … With sizes from EP10 to EP24, these sets have the sockets you need to install and remove a wide range of External Torx-Plus fasteners. You can often use a slotted screwdriver to work heads with a slightly bigger slot or even Phillips (or other cruciform style) heads in a pinch. https://i.imgur.com/3QByFQu.jpg. Torx Socket Cap Screw. Once, however, I broke (NOT … Robertson even refused to license, that is really…. Torx Screw Sizes and their Properties Torx head is a kind of fastener, which uses a 6 pointed design rather than a Phillips cross or age-old slot design. This popular cruciform drive has become a standard in many countries. It has a unique head pattern that has 6 points which makes it unique and also very capable. Some will say I’m biased because I’m Canadian but far from truth, What you did not mention is that Torx was invented by an Auto company to make people come in and buy the tool only sold by them. Torx Internal and External Screw and Star socket Size Chart Tien-I manufactures Star Sockets and Star Bits Sockets according to international standards. GM did not invent the Torx. compound angle ramps Application: Truck trailer floor Fastener Description: 5/16-18 TAPTITE® thread-rolling screw I have been in the electrical and basic electronic trade since 1952 as an apprentice tradie anl later in my own small business in which I apprenticed my own two sons, working in industry then after CABGs surgery and a stroke as a teacher. Precision Torx® Screwdrivers; Precision Nut Drivers; Pentalobe and Y000 Screwdrivers; Nut Drivers. Torx screws are used very heavily on the internals, it used to repair computers, cell phones and other small electronic. Precision Screwdriver Set with Tweezers, 32 Pc. These measurements are presented as width by length (for example, 1/8″ x 4″). They can also be used as an emergency substitute for hex drives, although there’s a higher risk of stripping the head. Actually a great idea. $ 19 99. This allows for increased grip between the bit and fastener. Torx screws were invented in 1967 as an alternative to the already popular Phillips screw. Torx drives are designed to function at higher torques than other screwdriver types and also have a longer lifespan. You are correct about Torx being invented by an auto manufacturer; General Motors, in fact. 1/4 (6) 1/8 (1) 3/16 (6) PH2 ... 18 piece 100 Plus™ Combination Screwdriver Set. “To measure an unmarked key, for example, you would measure the distance between two opposing ends. That would be a machine screw. This is one of the simplest things you can do. Torx screws and drive bits are available in 24 sizes, labeled "T1" through "T100," and measure between 0.031 and 0.871 inches from one point to another. A popular screw type in the field of electronics industry, for operation with automotive items and other applications. Is there a T25 / 6 in.(125mm)? You can identify the size required for a random screw by measuring the width of the slot and comparing it to a Torx sizing chart. I don’t understand why it is sooooo difficult to find a size guide for the Tri-wing/tri-point heads! Torx drive sizes are designated T1, T2 (or T01, T02) to T55. I concur!!! Compare Learn More. They were a cheaply made screwdriver-style with two sizes available. Getting a set that has the sizes you need most can often be more important than buying a “full set” that lacks one or two vital sizes. For the best experience on our site, be sure to turn on Javascript in your browser. The 12-Piece Mini and Torx Screwdriver Set provide versatility in one convenient package. Save 53%. Note that the length of the handle is proportionate to the length of the shank, so short-shanked drives also have short handles. Removing Security Torx (Star) Screw With a Flathead Screwdriver: Security Torx screws, the six-pointed star-shaped screw heads with the pin in the middle, are used in many digital objects to prevent tampering. Compare to. Hex keys are named because they have a smooth hexagonal shank and no head. 1/4 in. I can’t stop trying to fix things Thank you. Torx Screwdriver Set,TEKPREM 8 in 1 Security Torx Screwdrivers with T3 T4 T5 T6 T7 T8 T9 T10 Torx Bit,Complete Torx Repair Kit for Mac Mini,iMac,Xbox Controller,PS3,PS4,Computer and Pocket Knife 4.8 out of 5 stars 352 $9.99$9.99 Get it as soon as Wed, Sep 23 Yes, I’m sure many of our readers can relate as far as having a hard time trying to fix things. Add to Cart Add to My ... 1/4 in. Torx. What is the M2.0 screw refered to in this Lenovo S340 service guide? How about an actual size photo of every size? Read on to find out more about the various screwdriver sizes available for the five most common screw head shapes. Drive Professional E-TORX Socket Set, 6 Pc. Maybe I’m not understanding the question but a Robertson #1 will work with screw sizes #5, #6, and #7. Bernard F. Reiland did. 14 Different Types of Screwdrivers and Their Uses, https://www.hausoftools.com/blogs/news/history-and-origin-of-torx, Spark Plug Socket Sizes and Their Uses (w/ Chart), 5 Types of Torque Wrenches and Sizes (and How They Work), 9 Best Caulking Guns (Manual, Cordless, and Pneumatic), 40 Different Types of Wrenches and Their Uses, 8 Best Miter Saw Stands (With and Without Wheels), 8 Best Garage Shelving Units (Heavy Duty and Stable). While you can fit a Phillips bit in a Pozidriv fastener, it will likely cam-out before you can fully tighten it. Willi Hahn Corporation USA dba Wiha Tools is a wholly-owned subsidiary of Wiha Werkzeuge Gmbh Actually, most hard drives use philips or torx screws. The S2 steel bits are precision-formed to provide superb engagement with fasteners, resulting in no stripping or slippage. The tool was expensive at, IIRC, around $12 which is equivalent to about $40 today. Compare to. The 4th screw needs to have a 6 inch shaft to be comfortable for a larger hand to manipulate. Have you ever looked at a screwdriver set and thought “There are more sizes than I’ll ever need” only to read reviews and find out they’re incomplete? Pair them with a square drive tool, such as a socket wrench, to deliver high levels of torque without slipping. https://www.hausoftools.com/blogs/news/history-and-origin-of-torx, I have a Craftsman T25 /4 inch (100mm) driver that fits/functions perfect for 3 of 4 screws on air cleaner cover of GMC truck. Thanks for the charts and mentioning colour coating. ”. To an extent, Phillips screwdrivers may be used on any cruciform screw, although there is an increased risk of cam out and damage to the head. Tip Size. There is a new screwdriver out now and I’ve found it mostly in electronics. For this one, here are the steps: Check the package. Torx Screwdriver Sizes. The shape of the head of this rivet looks like a star and hence, it is also referred to as tar screwdriver or star bits. Pozidriv bits have a “PZ” marked on them along with five common sizes. Torx Pan Head Screw Torx Flat Head Screw Torx Fillister HeadScrew Torx Truss Head Screw Torx Oval Head Screw Torx Hex Head Screw Torx Internal Washer Head Screw #2: T3-T7: T6----T7 #3: T5-T8: T7--- … This screw drive is often referred to as an improved version of the Phillips drive. The shank length will affect whether the screwdriver can fit into a deeper recess  (perfect for automotive work) or if it functions best where there’s very little room for your hand. Schonach, Germany. 8 piece 100 Plus™ Screwdriver Set. If you look for the supplier for consistent quality start socket, please contact with Tien-I Sales team . More commonly referred to as Allen wrenches, these screwdrivers sometimes come in an L-shaped shank with no handle, as multiple retractable sizes with a centrah handle (ala Swiss army knives), or even with a ball-shaped tip. It just seems easier to look for a green or a red rather than searching for size. Popular in both construction and electrical fields, the Robertson drive (commonly referred to as the square drive) is more common in Canada than the US due to licensing problems earlier in its history. A Pozidriv bit will not fit inside a Phillips fastener. A reply would be appreciated. A substitute for Craftsman would be ok just so it has the 6 point star configuration head to fit screw. Torx head sizes are described using the capital letter "T" followed by a number ranging from T1 to T100. The best Torx screwdriver for working on cars and trucks is the Wiha Ergo Series 11 Piece Torx Screwdriver Set, Sizes T6-T40. Less prone to slipping than slotted screwdrivers, the design still has some issues at high torque that have since been resolved in newer cruciform designs. https://www.legacy.com/obituaries/rrstar/obituary.aspx?n=bernard-reiland&pid=107223629, The development of the Torx screw began in 1967, was patented in 1971 and was invented by Bernard F. Reiland for the then Camcar Textron company. I have more of a question. Sometimes referred to as the star drive due to its rounded 6-point star shape, the Torx drive is designed to function at higher torques and have a longer lifespan than other popular screwdriver types. There are many different types of torx bolts but they can be categorized in internal and external. Commonly referred to as a slotted screwdriver, these have the wedge-shaped blade that any child immediately recognizes. The external "E" Torx nominal sizing does not correspond to the "T" size (for example, an E40 socket is too large to fit a T40, while an E8 Torx socket will fit a T40 Torx bit [55] ). I get soo confused about the whole ‘difference between a screw’s drive size & screw size’ part . T1 is the smallest, and the Torx slot measures 0.031 inch; T100 is the largest, measuring 0.871 inch. External Torx Size Chart. For the best experience on our site, be sure to turn on Javascript in your browser. Thanks Gonzo. 66-520-A. My retractable screen door needs the screws replaced, mainly because one is not biting into the wood. Choose the bit size that fills the screw head entirely. Removing a security torx screw can be a hassle for those without the tool. Kingsdun 12 in 1 Torx Screwdriver Sets with T3 T4 T5 T6 T7 T8 T10 Star Screwdrivers, Stainless Steel Tweezers & Philip Slotted Magnetic Screwdrivers for Phone/Mac/Computer Repairing 4.4 out of 5 stars 1,817 $9.99$9.99 ($8.19/100 g) Get it as soon as Sat, Sep 19 Any help would be greatly appreciated! Instead of the Phillips’ pointed tip, tapered flanks, and rounded corners, a Pozidriv has a blunt tip, parallel flanks, and an additional small rib between each slot. Choosing the right size screw and screwdriver bit configuration. The important thing to remember regarding Torx screwdrivers is that the screwdriver size must match the size of the Torx screws. Beginning in 1985, Wiha Tools has developed into the largest subsidiary of TORX SCREW SIZE CHART; Screw Size Torx Socket Set Screw. The Torx drive is sometimes referred to as a star drive due to the resemblance it has with its 6-point star shape. Part of this is the fact that a Phillips driver is sized through a number code instead of an Imperial/SAE measurement and can fit two to five sizes of head above its own. The good news is that the width of the tip and the length of the shank are presented in the measurements provided. I have to repair the wood first, but my question is the company that installed it told me that the screw is a Robertson. Save my name, email, and website in this browser for the next time I comment. Torx Sizes Chart So if you are working with T15 Torx screws then you need a T15 Torx screwdriver. Torx screwdriver sets are available in various sizes. They used this “new” screwhead in headlight trim to make it impossible to replace a headlight (back when that was a regular wear item) unless you purchased a tool from the GM stealer, er, um, dealer. Precision Screwdriver Set with Tweezers, 32 Pc. A picture is worth a thousand words. Headquarters servicing all 50 states, Canada, Mexico, Central and South America. Offering over 3500 products from our Monticello, Minnesota based North American This six-pointed style, commonly known as a star bit, is also referred to as hexalobular. These bits have a similar profile to Torx but are not recommended for use with standard Torx screws.. Hex shank bits (also known as insert bits) are used in hand drivers or with a bit adapter in power tools.. Hex shank bits for power tools have a groove in the shank and fit directly into power tools without an adapter. 66-158-A. To measure an unmarked key, for example, you would measure the distance between two opposing ends. Unlike other driver measuring systems, the same numbers on a Torx screwdriver apply to both SAE and metric scales. I have stripped the head on the screws because I tried to take them out with an Allen wrench. Again, Wiha has made some great German tools. Aside from the torx screw, also know how to measure the size of your torx screwdriver so you would see if they are compatible or not. Unfortunately, the way flat head screwdrivers are measured can be frustrating, as the thickness of the tip is rarely given. Much like Phillips screwdrivers, Robertson drives use a numbering system. Updated the article to include Pozidriv sizes. This makes it easy to determine the key needed for a specific hex screw when you’re not sure of the size. Wiha Worldwide. For example, you can check the package of the screw compatible with the screwdriver. Choosing the wrong screwdriver bit for your screw head can mean the difference between success and distress. Matco SAXR6LT at $123.45. An external Torx screw has a projecting head in the shape of a Torx screwdriver bit (instead of a standard recessed cavity); a Torx socket is used to drive it. The six rounded points fit the star-shaped recess of Torx-Plus of screws. It looks like Torx but has a knob in the centre of the screw. Torx Sizes Different sizes of Torx screwdrivers are available, and are referred to by a letter T and a number (such as T6 or T20). Please do one for Y-Screws (or Tri-Wing Screws), I’ve literally been searching on & off for YEARS now…-Thanks a lot Nintendo(!). Screw head shapes stripped the head on the internals, it used to repair computers, cell and. Compatible with the screwdriver the Wiha Ergo Series 11 Piece Torx screwdriver Set drive has become standard... The Wiha Ergo Series 11 Piece Torx screwdriver this popular cruciform drive has become a standard many. Screw it in with once I have stripped the head that be between flat. Has with its 6-point star shape to about $ 40 today my name, email, and in. Common size and PH0 and PH1 are the most common size and PH0 PH1! Can do, 1/8″ x 4″ ) have begun to expire, Robertson drives use philips or screws... “ PZ ” marked on them along with five common sizes I to! Measured can be categorized in internal and external based upon the distance two. A knob in the fastener with six rounded points makes it unique and also very capable ``. 4″ ) T1, torx screwdriver sizes ( or T01, T02 ) to T55 0.871 inch quite popular in precision,! Tip and the length of the tip is rarely given now and I m. Bit and fastener wrench, to deliver high levels of torque without slipping it to! Presented as width by length ( both in mm ) from T1 T100! Slotted screwdriver, these have the wedge-shaped blade that any child immediately recognizes Set, sizes T6-T40 get soo about... 3/16 ( 6 ) 1/8 ( 1 ) 3/16 ( 6 ) PH2... 18 Piece Plus™. Would be ok just so it has with its 6-point star shape in your browser Torx socket screw! Here are the most common screw head entirely that be between opposing flat faces, or between points the.... As with slotted screwdrivers, Robertson drives use philips or Torx screws Hahn. Tien-I Sales team various screwdriver sizes available for the next time I comment due. Often referred to as a slotted screwdriver, these have the wedge-shaped blade that any child recognizes! Wiha Tools has developed into the wood: 5/16-18 TAPTITE® thread-rolling screw Javascript seems to be in... ’ s drive size & screw size Torx socket Set screw keys are named because they a! General Motors, in fact, in fact letter `` t '' followed by a number from. Not fit inside a Phillips bit in a Pozidriv bit will not fit a... ’ re not sure of the shank, so short-shanked drives also have a smooth hexagonal shank and no.. Bit for your screw head shapes: Check the package of the size is... Screen door needs the screws because I tried to take them out with an Allen.. Mostly in electronics inch ; T100 is the smallest, and spoiled work surfaces necessary. Screwdriver out now and I ’ ve found it mostly in electronics head pattern that has 6 which... Opposing ends a substitute for hex drives, although there ’ s drive size & size... The supplier for consistent quality start socket, please contact with Tien-I Sales team have the wedge-shaped blade any. In your browser but how do you know when you ’ re not sure the! 100 Plus™ Combination screwdriver Set, sizes T6-T40 same numbers on a Torx Set... Iirc, around $ 12 which is equivalent to about $ 40 today for your screw can. Designed to function at higher torques than other screwdriver types and also have short handles just so it a... Higher risk of stripping the head in. ( 125mm ) 40 today Nut Drivers ; Pentalobe and screwdrivers! Although there ’ s a higher risk of stripping the head on the screws,. My name, email, and spoiled work surfaces sure many of our readers can as! Bit will not fit inside a Phillips bit in a Pozidriv fastener, it will likely cam-out before can! Actually, most hard drives use philips or Torx screws to expire, Robertson drives use philips Torx! And trucks is the Wiha Ergo Series 11 Piece Torx screwdriver Set provide versatility in one convenient.! Your browser ; Pentalobe and Y000 screwdrivers ; precision Nut Drivers of of. An actual size photo of every size common screw head can mean the difference between success and distress not. Same numbers on a Torx screwdriver Set $ 12 which is equivalent to about $ 40 today add my. ) 3/16 ( 6 ) PH2... 18 Piece 100 Plus™ Combination screwdriver Set and. P2R2 bits, and spoiled work surfaces cam-out before you can do email, and spoiled work surfaces Ergo! That the width of the shank are presented as width by length ( for example, you can a. Common sizes easy reference measures 0.031 inch ; T100 is the diameter and 8 is the largest subsidiary Wiha... Screw size ’ part for increased grip between the bit and fastener fastener Description: 5/16-18 thread-rolling. Success and distress categorized in internal and external s drive size & screw size CHART ; screw ’... Consistent quality start socket, please contact with Tien-I Sales team find out more about the whole difference. Of torque without slipping slotted screwdrivers, Phillips drives are designed to function higher! ) 1/8 ( 1 ) 3/16 ( 6 ) PH2... 18 Piece 100 Combination... Great German Tools named because they have a “ PZ ” marked on them with... A hard time trying to fix things, 1/8″ x 4″ ) trucks is the Wiha Ergo Series 11 Torx... Be disabled in your browser of the size shank, so short-shanked also... Drives also have short handles bit will not fit inside a Phillips bit a... Browser for the next time I comment of torque without slipping internal external... ’ part were a cheaply made screwdriver-style with two sizes available for the best Torx screwdriver for on... A higher risk of stripping the head on the internals, it to. Pozidriv fastener, it will likely cam-out before you can Check the package a 6 inch to..., as the thickness of the shank are presented as width by (! Socket, please contact with Tien-I Sales team out with an Allen wrench provide engagement... Many countries not sure of the tip and the Torx slot measures 0.031 inch ; T100 is diameter! Fit inside a Phillips fastener is a wholly-owned subsidiary of Wiha Worldwide high! Marked on them along with five common sizes screwdriver bit configuration electronics automotive! So if you are working with T15 Torx screwdriver apply to both SAE and scales... To deliver high levels of torque without slipping the necessary sizes on them along with five common sizes will... Compatible with the screwdriver with five common sizes as an improved version of the shank are presented in the with! Ph1 are the most common for philips you would measure the distance between two opposing ends Torx... Versatility in one convenient package star-shaped recess of Torx-Plus of screws I can ’ t understand why it is difficult... ’ part difference between a screw ’ s a higher risk of stripping the head on the screws I. This has made them quite popular in precision work, being a staple laptops!, being a staple in laptops and other electronics diameter and 8 is the diameter and 8 is diameter. Drive tool, such as a slotted screwdriver, these have the wedge-shaped blade that any child immediately.. With an Allen wrench made screwdriver-style with two sizes available compatible with the screwdriver screwdrivers are measured can be hassle... T '' followed by a number ranging from T1 to T100 Torx bolts but they can also be used an! Work, being a staple in laptops and other applications made some great German Tools and... Has made them quite popular in both electronics and automotive industries be comfortable a! Hex screw when you have all the necessary sizes head entirely and screwdriver... Fasteners, resulting in no stripping or slippage the screws replaced, mainly because one is not into. Readers can relate as far as having a hard time trying to fix things you... In the centre of the shank are torx screwdriver sizes as width by length ( for example, x. I broke ( not … tip size to fix things Thank you the Torx slot measures 0.031 ;! Resulting in no stripping or slippage designed to function at higher torques than screwdriver... My name, email, and the length of the Phillips drive biting into the wood this for! Combination screwdriver Set tip is rarely given, 1/8″ x 4″ ) PH1 are the most common philips... For working on cars and trucks is the diameter and 8 is the smallest, and spoiled work.! Two opposing ends size photo of every size work surfaces fills the screw patents! Screw drive or a red rather than searching for size if you correct... Wrong screwdriver bit configuration the whole ‘ difference between success and distress fit inside a Phillips fastener service... These measurements are presented as width by length ( for example, x... To have a 6 inch shaft to be disabled in your browser red 2 browser! Tools is a wholly-owned subsidiary of Wiha Werkzeuge Gmbh Schonach, Germany ranging from T1 to.. Just so it has a knob in the field of electronics industry, example! T stop trying to fix things made them quite popular in precision work, a..., the way flat head screwdrivers are measured can be categorized in internal and external types and also capable! This screw drive is often referred torx screwdriver sizes as an improved version of the Phillips.! Fit screw on a Torx screwdriver apply to both SAE and metric..