4235 : Part 1 : 1972) Inch Square Parallel Keys & Keyways (B. 202 to 1012 Height Width Diameter Actual Length Full Radius Flat Bottom Distance Key Below Center No. However, in cases of dispute of the individual keyway depths. Mon - Fri: 8:30 am - 6 pm EST. S. coordinate dimensions due to the direct functional relationship of the 2 holes. BALDOR ELECTRIC COMPANY P. The keyway dimensions are also different from the English system. The keyway dimensions are also different from the English system. Keys that meet ANSI B17. 1 Class 1 standards for dimensions and tolerances. Shaft Keyway Shear and Yield Strength Formulae and. The key prevents relative rotation between the two parts and enables torque transmission. W = d/4[clarification needed] H = 2d/3[clarification needed] where. SAE CodeMachine Key Comprehensive Guide. 2; Thread Shear Area for External and Internal Formulas and Calculator per. Shaft (Arbor) Keyway Dimension Size Data - ANSI/ASME B94. These idler sprockets have two rows of teeth for use with double-strand ANSI roller chain. ds991933-Woodruff keys - Shaft diameters, dimensions of corresponding Woodruff keys and keyway depth in shaft and hub-Customer Service: 212 642 4980. 0. ANSI Approved: No DoD Adopted: No FSC Code: 5315 - Nails, Machine Keys, and Pins Document History: NA0139 (Complete Document ) Active, Most Current Currently Viewing. Created Date: 1/23/2014 8:35:20 AM. Rather than enjoying a fine PDF later a cup of coffee in the. *1 BSW (British Whitworth) threads are completely interchangeable with ANSI (American Standard Unified) except not in the case of 1/2". 4375 PageRoyMech Resources Keyways Woodruff Metric key and Keyway Dimensions These Pages include various standards. 332 Maximum 3. Lag Screw Metric Size and Dimensions per. 5M is the standard for dimensioning practice in the USA. special bore / keyway dimensions). keyways /keys dimension in accordance with BS 4235-1:1972: Specification for metric keys and keyways - Parallel and taper. 3. 3) Keyway fillet radius to be specified by customer. 0 Cart. Keyway Width Measurement. dimensions contained in ANSI/AGMA 9002--A86 represented the dimensions and. The keys and keyways followed the recommendations of ISO R773:1969 and shaft tolerances followed ISO R775:1969. 238 0. 69 inch. ANSI-AGMA 9002 defines standard bore and keyway dimensions for shafts dimensioned in inch units, and ANSI-AGMA 9112 defines standard bore and keyway dimensions for shafts dimensioned in metric units. Axial run-out locating face/thread: 0,06 to 0,16 mm max. Hub keyway depth is one-half the nominal height of the key and measured from the side corner. While a designer is free to specify any keyway they wish, straying from the standard option is likely to increase the cost, time, and complexity of the part. g. 4235 : PART 1 : 1972. From the right side of the shaft total diameter is given with tolerances. ANSI-B17. Stock lengths from 3 feet to 24 feet. Caliper Diameter Bore Pitch Dia. ANSI/AGMA 9112-B14 describes sizes and tolerancesSlightly larger than the size listed, these oversized keys offer a tight fit in worn keyways. - Series EL couplings supplied with Nominal key size b × h Applied shaft diameter d Key size Keyway size; b h c or r Standard size of b1 and b2 b1Tolerance （h9） b2 tolerance （E9） r1 and r2 t1 t2; Standard size Tolerance（h8） Standard size Tolerance(h10) Standard size Tolerance Standard size Tolerance; 4×4: 10 or more and 13 or below: 4: 0 -0. Looking for additional engineering information about our tools? Here you can find the dimensions, torque ratings, and more for our products. 068. ) max. 8. 000 + 0. (ANSI/AGMA 9002-B4) Nominal Shaft Diameter ( A ) Bottom of Keyway to Bottom of. The inch and metric dimensions here correspond to common values. Set Screw Type E. Most likely you have knowledge that, people have see numerous time for their favorite books taking into consideration this Ansi Standard Keyway Sizes Pdf, but end in the works in harmful downloads. Most manufacturers of sprockets conform to the ANSI (American Standards Institute). 1-1943 Standard. The intent of this document is to offer designers and users of flexible couplings preferred dimensions, tolerances and fits for metric bores and keyways. Each tooth’s cutting edge is a few thousandths of an inch larger than the one before. A Hole Callout is inserted and the Dimension PropertyManager appears. 1 Keyway Dimensions - Lowell CorporationAGMA 9002-A86 Inch Bore and ANSI B17. Sign-In Create Account. 4. BSR/ASHRAE Addendum a to ANSI/ASHRAE STANDARD 140-2001 1 (Note: Additions are shown in this addendum by underlining and deletions are shown by strikethrough except when an informative note makes it clear that the entire material that follows is to be added or deleted as a whole. Our 120 roller chain sprockets are supplied with hardened teeth as a standard for tooth counts 30 and below, are made from a high-strength steel, and are typically black oxided for. com Web site: This standard presents metric dimensions, tolerances, sizes and fits for straight bores, tapered bores, keys and keyways for unmounted industrial flexible couplings. The following is summarized from the American National Standard Keys and Keyways for Milling Cutters and Arbors ANSI/ASME B94. 0625 0. ANSI B4. Go to: SAE Two Bolt Mounting Flange . ) CONTENTS [Informative Note: Revise the table of contents as. It’s the same shape and position as the right Alt key, so we’ve. Ansi B17 1 Standard Keyway Dimensions Lowellcorp Recognizing the showing off ways to get this ebook Ansi B17 1 Standard Keyway Dimensions Lowellcorp is additionally useful. More corrosion resistant than 18-8 stainless steel set screws, these have excellent resistance to chemicals and salt water. you to acquire the most less latency epoch to download any of our books subsequently this one. Standards such as BS 46, ANSI B17. Metric keyways are dimensioned by width and depth as measured from the radius of the. 7530 3. Nominal Dia. Minimum keyseat width is that figure. Nonetheless below, when you visit this web page, it will be properly no question easy to get as without difficulty as fetch tutorial Imperial Woodruff Key Keyway Dimensions . S. Install in a keyway to transmit torque from shafts to gears and other components. 1 Keyseat Alignment Tolerances: A tolerance of. 88 4 2-6 XX Model Special designation only (e. Related terms:. 8mm 3. Failure to do soKeyway broach 1/16 to 1-1/2 inch, 2. Shaft (Arbor) Keyway Dimensionl Data - ANSI/ASME B94. 314 Maximum 3. Related: Shaft Arbor and Keyseat Dimensional Data American National Standard Keys and Keyways; Standard Metric Keys Keyways for Metric Bores with One Key; Keyway Cutter Hole Keyway Dimensional Data for MIlling Centers and Arbors - ANSI/ASME B94. Bores and Keyways for Flexible Couplings, Inch Series. b x h width x thck. ANSI/AGMA 9002--B04 supersedes the information from ANSI/AGMA 9002--A86, Bores and Keyways for Flexible Couplings (Inch Series) . 2 Axial run-out locating face/thread: 0,05 to 0,30 mm (0. 001) of an inch. Their extra depth in shaft reduces the overturning tendency in its keyway. The following tables show standard dimensions for keys and their grooves. 003, -. BS 4235-2:1977, ISO 3912-1977: Specification for metric keys and keyways - Woodruff keys and keyways. sites. 30 3. Mount them onto your shaft and secure with a set screw— no machining necessary. ISO R 773 and. Standard Design Fits for Parallel and Taper Keys per. A sprocket with an internal parallel keyway. Dimensions in engineering drawings are shown in units of length and angle. Machine keys – also called shaft keys or key seats - are removable machine elements installed between shaft key seats and hub keyways to transmit torque in power transmission assemblies. Max. Link. DIN or ANSI keyway optional Ø D 2 H7 1 Ø B C C A Ø B S G H E ISO 4762 F MODEL EK2 SIZE 20 60 150 300 450 800 Type (Elastomer insert) A B C A B C A B C A B C A B C A B C Rated torque (Nm) T KN 17 21 6 60 75 20 160 200 42 325 405 84 530 660 95 950 1100 240 Max. 8mm 2. ForHigh-Security Key-Actuated Light Switches. standards/Din 8187/Din 8188; Iso R 606;ANSI 29. The keys and keyways followed the recommendations of ISO R773:1969 and shaft tolerances followed ISO R775:1969. Size, bxh 1 1/4. The gap of the keyway is shown with tolerances again and the semi-gap is shown. Undersized Machine Key Assortments Since they fit more loosely than standard keys, these undersized keys are best for uneven keyways or when you need to disassemble parts frequently, such as during maintenance or prototyping. Key Size. Metric keyways are dimensioned by width and depth as measured from the. The tolerance zone for shaft keyway width b with normal fit is ISO N9 and with close fit ISO P9. Keyway metric pdf edge. 442 2-5/16. ). Consent to Cookies & Data processing. 201 202 1/16 x 1/4 0. 016 1/64Use them to connect gears and other components with tapered keyways to shafts. Related: Shaft Arbor and Keyseat Dimensional Data American National Standard Keys and Keyways; Standard Metric Keys Keyways for Metric Bores with One Key; Keyway. 1. ANSI Keyway Dimensions Dimensions Info. A common key for all three levels of security enhances key control and simplifies administrative procedures. ANSI/AGMA 9112-B14 describes sizes and tolerances Slightly larger than the size listed, these oversized keys offer a tight fit in worn keyways. Undersized Key Stock Assortments. Dimensioning and Tolerancing Engineering Product Definition and Related Documentation Practices AN INTERNATIONAL STANDARD ASME Y14. Ansi B17 1 Standard Keyway Dimensions Lowellcorp Author: blogs. 30 2. 010 / -. din68851967-Drive Type Fastenings without Taper Action; Parallel Keys, Keyways, Deep Pattern for Machine Tools, Dimensions and Application (Foreign Standard)- Customer Service: 212 642 4980could enjoy now is imperial woodruff key keyway dimensions below. Socket Set Screws Mechanical Properties ASME B18. Designation - designated as: A parallel key of Type A, width 12 mm, height 8 mm and length 50 mm shall be Parallel Key A 12 x 8 x 50 4. It is vital to have the correct fit between the shaft keyway, key and hub keyway. Standard External Metric Thread and Fastener Sizes M 0. Information and documents presented . The ANSI B4. Nominal Bore Diameter 3/8 7/16 1/2 9/16 5/8 11/16 3/4 13/16 7/8 15/16 1-1/16 1-1/8 1-3/16 1-1/4 1-5/16 1. The pitch diameter is calculated like for a standard spur gear by multiplying the module with the number of teeth: d. More corrosion resistant than 18-8 stainless steel set screws, these have excellent resistance to chemicals and salt water. The following is listing of those standards: Standard Description BS4235 P Woodruff keys and keyways – same as ISO 391 BS46P1 Specifications, Keys and Keyways – obsoleteansi-b17-1-standard-keyway-dimensions-lowellcorp 1/1 Downloaded from coe. Bore and Keyway dimensions comply with ANSI/AGMA 9002-B04 Standard. ANSI B17. /Rect. 0625 0. 002 to 0. 004, -. ANSI Approved: No DoD Adopted: No Document History: ISO 2491 (Complete Document ) Not Active Currently Viewing. 3-2003. Keyseat Alignment Tolerances: A tolerance of 0. 1 - 2,800 Nm A/A F L/L F R Ø O 1 h7 Ø E Ø O h7 H I depth J K actuation distance see table pin hole for torque adjustment wrench Ø B/B F Ø D H7. stock image. 80. The last two digits give the nominal diameter B in eighths of an inch and the digits preceding the last two give the nominal width W in thirty. Finished bore sprockets are commonly referred to as a "type B" or "type BS" sprocket. Box 12086 Omaha, NE 68112-2086 Gear Products and Suppliers | Gear Knowledge Menu. 750. AGMA 9002-A86 Inch Bore and ANSI B17. DIN-Keys & Keyways to ISO Diameter d in accordance to DIN 6885/1 in accordance to DIN 6885/3 above to Width b 1) Depth h Shaft Keyway Depth t₁ Hub Keyway Depth d = t₂ Width b 2) Depth h Shaft Keyway Depth t₁ Hub Keyway Depth d = t₂ mm mm mm mm mm mm mm. O. scope: This standard establishes a uniform relationship between shaft size and key size for parallel and taper keys retaining similar basic sizing as found in the withdrawn B17. Schlage - L460P Cylinder x Thumbturn. Metric External Table Chart Thread Designations Sizes M 1. ANSI is the American National Standards Institute's standard keyboard layout that America, Australia, Canada and also many Middle-Eastern and Asian countries use. Consult Options and Accessories section for other available strikes, sizes and configurations. This key stock is undersized, so keys will fit slightly more loosely than standard keys and are best for inconsistent keyways. Without Keyway. In ANSI keyboards, the left shift key is one large wide rectangular key. Are there any standards for Metric bores and / or keyways? There many standards that cover the topics of metric bore tolerances, fits and keyway sizes. keyways available upon request. 5 - 10 Standard with clamping collar STANDARD DESIGN | SIZE 15 - 2,500 Standard with conical clamping bushing WITH CONICAL CLAMP 0. ANSI-B17. Here we can calculate rigid connections, namely the pinned, keyed, splined and flanged ones. The intent of this document is to offer designers and users of flexible couplings preferred dimensions, tolerances and fits for metric bores and keyways. Mon - Fri: 8:30 am - 6 pm EST. PFEIFER INDUSTRIES, LLC. It proved useful in establishing dimensions and tolerances for custom engineered coupling products. ANSI Standard Woodruff Keys ANSI B17 2 1967 R1998. 25 - M 1. Woodruff Metric key and Keyway Dimensions. 7500 3. Customers may specify a key size that is one size larger or smaller than the standard size specified by the ANSI-AGMA specifications. The height of metric keys decreases by 1 mm for every 100 mm of length. fsu. ANSI woodruff size charts express measurements in inches and nominal key sizes with higher numbers corresponding to bigger keys. ANSI/AGMA 1010-F14. Undersized Machine Key Assortments. 000 +. Customer Service: 212 642 4980. 324 Minimum 3. Recommended uniform relationship between shaft diameter and key sizes for parallel and taper keys. Fully threaded, headless screw with a hexagonal drive at one end and a cup-shaped indentation at the other. The first is Js9. ICZW Keyway Broach Set HSS Keyway Cutting Tool for Lathe Metric Size Broaches with Bushings and Shims (22 pcs) 2 offers. Motor Mass Torque Equation and Calculator. Woodruff Keys Non Rok Hi Pro Metric. 2 standards for dimensions and tolerances. 010Bore Diameter Size Bore. Keyway width (wky) is measured by one of the following: (1) Go and no. Max. Schlage C Keyway, Schlage E Keyway, Schlage S123 Keyway. 2. 1, the Metric key size is W x T. 4" ANSI strike with curved lip to meet ANSI A115. get the Ansi B17 1 Standard Keyway Dimensions Lowellcorp associate that we find the money for. Page 7/11Ansi B17 1 Standard Keyway Dimensions LowellcorpAs this ansi b17 1 standard keyway dimensions lowellcorp, it ends upTo get a quote on #60 roller chain sprockets or if you have any questions please contact us and we will be happy to assist you! Phone: (407) 347-3519. This standard presents inch dimensions, tolerances, and sizes for straight bores, tapered bores, single keys and keyways for unmounted. DIN 6885-1:2021 Drive type fastenings without taper action, parallel keys, keyways - Deep pattern - Part 1: Dimensions, tolerances, mass. Please note that the key sizes in parentheses are older sizes that are no longer commonly used. ANSI Standard Woodruff Key Size Table Chart ANSI B17. Keys and keyways. Created Date:Keystock - 1/8" x 1/8" x 3 Ft - 316 Stainless Steel - Plain - Undersize - ASTM A484 - Pkg Qty 2#120 Roller Chain Sprockets 120 sprockets are manufactured for 1. 0005-. 396 Maximum 3. Key Type. An ISO keyboard layout follows the standards set by the International Organization for Standardization and most obviously differs from an ANSI layout by its upside-down L-shaped Enter key that sits. 1 Keys and Keyseats, based on current industry practice, was approved in 1967, and reaffirmed in 1989. Joined: Jun 2009 Posts: 978When installed, these keys fill oval keyways completely, reducing stress on the key and shaft. 30 3. 1 Square Keyway Tolerances Minimum 3. SCOPE. To ensure the correct fitting the width and height dimensions of standard key and keyseats must be held to recommended tolerances. In order to transmit rotation from the shaft to the hub of gear wheels, pulleys, sprockets, couplings, flanges and other coaxial parts, rigid and frictional joints of various types are used. 0000 0. Min. 000 -0. This Standard covers the size, type and tolerances of parallel and taper keys and keyseats, and their relationship to shaft diameters and bore diameters. For technical drawings and 3-D models, click on. ASTM Book of Standards. Shaft Keyway Shear and Yield Strength Formulae and Calculator. Typed-in dimensions are bad practice in CAD, especially 3D CAD like SolidWorks. 00075-0. Keyways, Dimensions and Application . Keys different istock onlyStandard and metric keyway broaches Chart and key. H is the key height. Standard External Metric Thread and Fastener Sizes M 0. Max. Standard. The keyway dimensions are also different from the English. As noted above, when selecting a keyway tolerance, there are two common selections in the metric system. ANSI B18. 1 Square Keyway Tolerances - Free download as PDF File (. *Hub size may require smaller setscrews in some instances. 1. 1 Wrench Openings; Ratchet Arm Attachment; Lowell Design Guides; Enter your email below for a FREE copy of our Official Engineering Whitepaper:Benefits of Standard Keyway Sizes Nearly every shaft diameter has a corresponding standard keyway width and depth. In stock and ready to ship. DIN or ANSI keyway optional MATERIAL Clutch system: hardened steel Clamping collar: up to size 500 aluminum, size 800 and up steel DESIGN With clamping ring and one clamping screw. English Dimensions: Keyway: W x T Key: W x T. 010 Height (d) (t) - DIM Keyway Width (w) AGMA 9002-A86 Inch Bore and ANSI B17. Transeals keyway chartKeyway chart pdf Standard woodruff keysWoodruff keys dimensions standard table inches key ansi. 8mm 2. h. 0000 4. Shaft keys are important machine components designed to. 19-1997; Design of Square Key and Keyway (Wood Ruff) Stress, Shear. Link to this Webpage: Copy Text to clipboard. 12. 1 - 2,800 Nm Ø G pin hole for torque adjustment wrench DIN or ANSI keyway optional N ISO 4762 P Ø F ±0,2 Ø E h7 Ø O 1 Ø O 2 h7 Ø D H7 Ø O Ø B/B F R I L/LF C A/A F H J K M. Publisher Collections; Standards Connect; Standards Packages;ANSI-B17. txt) or read online for free. If there is a fourth symbol on the key, this is accessed by pressing Shift and Alt Gr. The keys are square or rectangular. Description Keyway 100 KN11 XX How to Order Example security leg® The Yale® KeyMark® keyway has three distinct components: an upper portion or blade, a middle ledge, and a unique, lower angled portion or leg which exits the plug at an angle. Types are plate type, simplex, duplex & triplex body with plain bore or. M10 x 1. Durable. We stock pre keyed shafting in many diameters, including metric diameters, with standard keyways. Metric keyways are dimensioned by width and depth as measured from the radius of the shaft to the center of the keyway. E-mail: info@pfeiferindustries. 49 4 M i4 Ms ai l gn lm m e Mn t4 FMm u Mdm Um 49 4 M i4 Ms ai l gn lm m e Mn t4 FMm u Mdm Um 450 630-852-0500 Safety Warning ED-2 When using Lovejoy products, you must follow these instructions and take the following precautions. Fit Range a. The keys and keyways followed the recommendations of ISO R773:1969 and shaft tolerances followed ISO R775:1969. The keyway is a longitudinal slot in both the shaft and mating part. , depending on the lock nut size: ANSI/ABMA Std. 010 Height (d) (t). 3mm 3. In drawing practice, the preferred SI unit of length is the. 3750 7/16 . Publisher Collections; Standards Connect; Standards Packages;. 1; Keyway Cutter Hole Keyway Dimensional Data - ANSI/ASME B94. 2180 Corporate Lane, Suite 104 ~ Naperville, IL 60563 USA Phone (630) 596-9000 Fax (630)2 Ansi B17 1 Standard Keyway Dimensions Lowellcorp 2023-04-07 tolerance of 0. 625 +0. 250 0. DRILLING. Unless otherwise specified, the shaft keyway is assumed to be standard. Merely said, the Ansi Standard Keyway Sizes Pdf is universally compatible with any devices to read keyway chart hallite web keyway chart the following tables show standard dimensions for keys and their grooves metric rectangular b s 4235 part 1 1972 imperial rectangular b s 46 part 1The hub keyway is dimensioned by its width and depth on the shaft – keyway sides. 1st Edition, August 15, 1974. In stock and ready to ship. 1 - Keyway_Dimensions For Later. imperial woodruff key eBay. Keyway toleranceKeyway-and-key-size-dimensions. ANSI/AGMA 9112-B15 describes sizes and tolerances Key Dimensions. Documents sold on the ANSI Webstore are in electronic Adobe Acrobat PDF format,. ANSI H7 ISO H7 0. Check Details. The interference fit standard for most couplings made of medium-carbon steel are 0. As an example, for a one inch treadedAGMA is happy to announce the publication of a new standard: ANSI/AGMA 1012-H23, Gear Nomenclature, Definition of Terms with Symbols, written by the AGMA Nomenclature Committee. S. 5 - 10 Standard with keyway mounting STANDARD DESIGN | SIZE 15 - 2,500 Standard with keyway mounting WITH KEYWAY CONNECTION 0. Woodruff key is essential for operating high speed. Keyway Bore Diameter Size Bore Reference -0. Product data for lock nuts requiring a keyway. ANSI/AGMA 9112-B15 describes sizes and tolerancesKey Dimensions. 1, the Metric key size is W x T. 00050-0. AGMA ASA Keyway and Bores Design Data including dimension and tolerances. Roller Chain Sprockets - A. Keyway chart. One set screw is centered on the keyway and the other at 90 degrees. 004 - 0. ja 10 – 24 60 sh, sds, sd 1/2 – 20 108 sk 5/16 – 18 180 sf 3/8 – 16 360 e 1/2 – 13 720 f 9/16 – 12 900 j 5/8 – 11 1620 m 3/4 – 10 2700 n 7/8 – 9 3600 p 1 – 8 5400 w 1 1/8 – 7 7200 s 1 1/2 – 7 9000 warning: use of anti-seize lubricant on tapered cone surface or on bolt threads whenRe-design the shaft shown below to be a uniform,Standard keyway dimensions Woodruff ansi keyway fasteners nominalKeyway shaft coupling hole service modification additional tapered parallel couplings. Key Dimensions. Keyway (Hub) Radius r. Steel keys offer good strength. Thank you extremely much for downloading Ansi Standard Keyway Sizes Pdf. 9. 1 - 2,800 Nm Ø G pin hole for torque adjustment wrench DIN or ANSI keyway optional N ISO 4762 P Ø F ±0,2 Ø E h7 Ø O 1 Ø O 2 h7 Ø D H7 Ø O Ø B/B F R I L/LF C A/A F H J K M. 1875 0. 19. Depth Tolerance. Larger diameters must be selected in order to ensure that the shaft will be able to withstand the full torque of the application. sometimes referred to as a keyway. Exceeds 400,000 ANSI cycles Medium traffic ANSI/BHMA certified A156. special bore / keyway. +40 0. Point. 120. 376 . Check Details. Set Screw Type G. 0015 0. ship between shaft size and key size for parallel. 093 / . Keyseat Cutter Hole. 3/8 . Regardless of which unit of length you're using, you'll need to measure the following: width, height, and length. The differences are highlighted in red in the images below. Specify size, product name, part name, material and flange accommodation when ordering spare parts. marketplace position in the global economy while helping to assure. 104 0. Rather than enjoying a good book with a cup of coffee in the afternoon, insteadDIN or ANSI keyway shown displaced C 1 C DIN or ANSI 2 keyway DIN 916 FIXED DISENGAGEMENT TORQUE The ESL coupling is unlike other R+W safety couplings in that the disengagement torque is permanently set and tamper proof. Standard Key and Keyway Sizing. Typical steels for. In some cases, you likewise realize not. 1; Hardware Design Information Misc. 3. Keyway Dimensions Armstrong Metalcrafts. 4mm 1mm 1. Use them to connect gears and other components with tapered keyways to shafts. I would be curious about how your depth value got there. 2 Size Description The need for interchangeability of parts is the basis for modern dimensioning (see ANSI / ASME Y14. Therefore, the majority of factories in North America are likely to have. 1-1967 (R1998) ANSI B17 1 PDF - C-4-C Feather Keys | McMaster-Carr Ansi B17 1 Standard Keyway Dimensions Lowellcorp ANSI-B17. 0005 / -. Placement of all text to be read from the bottom of the drawing is called unidirectional dimensioning. Imperial machine have dimensions listed in imperial units also referred to as the imperial system and are listed as ANSI - ASME standard machine keys. ) max. This standard describes sizes and tolerances for straight and tapered bores and the associated keys and keyways, as furnished in flexible couplings.