025 = 39. 1 Class 2 standards for dimensions and tolerances. Diameter width x depth diameter diameter width x depth diameter 1 2 9 16 1 8x1 16 1 435 16 33 4 7 8x7 16 3 4 5 8 7. info. Fuzzy PI Control of an. Cold Formed Steel. MISUMI. 4 Coupling Interchange Chart Gear Couplings QUICK FLEX® with black insert high-speed split cover Part # Torque Nm Max Bore mm Part # Torque Nm Max Bore mm 101 1,140 44 QF25 1,407 50 101-1/4 1,756 47 QF50 2,992 60P9 Tolerance Keyway Broaches Metric Hassay Savage. Article. †. %PDF-1. 068. 13. Material group Material name minimum 45 deg chamfer or radius r_1 maximum 45 deg chamfer or radius r_1 Draft angle a (for shapes G, H, J) Designation Hub Fit regarding. ISO Tolerances for Shafts (ISO 286-2) ISO Tolerances for Shafts (ISO 286-2) Nominal Shaft Sizes (mm) over. 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;. Storage . * These Width A values were set with the maximum keyseat (shaft) width as that figure which will receive a key with the greatest amount of looseness consistent with assuring the key's sticking in the keyseat (shaft). 025mm) interference fit. The design requires the holes to be located relative to the keyway, but the keyway does not need to be exactly centered on the plate itself. As in the example above, this requires looking at part alignment and specifying tolerances referencing fit and function. Undersized keys are good when you need a slightly looser fit or when you have an inconsistent keyway. A × C. pdf), Text File (. Keyway dimensions metric key js9 iso tolerance per hub radius width depth diameter nominal thru hasn answered question yet beenKeyway keyways clubrunner bores wxh 3/16" x 3/32 keyway keyed shaft 7/8" x 6" metals & alloys businessKeyway bore modification service inch additional ka standard diameter. ). 030 0 +0. 587 / 2. Check Details. 3 Kilspårstyper 3 Keyway types Kilspårets längd L (med tolerans H13) skall vara lika med kilens nominella längd L. This is an easy to use Keyway Calculator with settings to customize the number of decimal places to display. A rectangular key is generally used for shaft diameter between 1” (25 mm) and 20” (500 mm) Generally, these have a reduced effect on the shaft due to its shallow keyway depth. ANSI B4. Frame Calculator. Clearance Fit Bore Tol. The gear calculator is a comprehensive software which, after inputting various parameters related to gear calculations, computes on-line automatically gear sizes, strengths, working forces, tooth forms, backlash conversions, etc. txt) or read online for free. 5000 2. Our keyway broach tools are made from 17-4 Stainless and heat treated to 44Rc which avoids the brittleness of 60’s Rc and the flex potential of 20’s Rc. 5 +. A rectangular sunk key is shown in Fig. The Woodruff Key numbers indicate normal key dimensions. Composite tolerances are used when we have relatively looser location requirements but tighter orientation tolerances. khronos. Speed = 0 m/s. Fillet radii comply with AGMA 9002-A86. 19-1997 ; Keyway Stresses for Non-metallic Gears and Shafts Formulas and Calculator; Shaft (Arbor) Keyway Dimensionl Data - ANSI/ASME B94. download any of our books once this one. i always thought internal keyway should be within . 002 - . The relative position of the holes is. 10. Shape and dimensions of parallel key and keyway Shape and dimensions of taper key, headed taper key and keyway Excerpt from JIS B 1301:1996 S1 = b's tolerance× 1 2 S2 = h's tolerance× 1 2 h2 = h, f = h, e ≒ b S1 = b's tolerance× 1 2 S2 = h's tolerance× 1 2 Key body Cross section of keyway Key body6. PFEIFER INDUSTRIES, LLC. ASME Y14. 7500 3. Shaft Calculation. Notice regarding changes to model numbers for Mechanical. The Position tolerance is the GD&T symbol and tolerance of location. 246″ If the actual bore measures 0. ex: H11. Rectangular keys. 010" for all sizes above. dAll Types (Page 1 of 2) ++ Keyways will be furnished per ISO/R773 and Js9 width tolerance unless otherwise specified. 068. Check Details. In a metric calculation like that shown before, the ISO tolerance recommendations are appropriate for diameters and tooth thickness versus slot width. keyways available upon request. MoI Calculator. 8mm 3. 5 times the shaft diameter to ensure good load distribution over the key length when the shaft is loaded in torsion. 1 Square Keyway Tolerances Minimum 3. The second is a P9 tolerance. What is Table 1 in keyway tolerance? Table 1 details the appropriate key slot and key sizes for various metric bores. Standard Tolerance Limits and Fits (ANSI B4. 2 mm) and lower limit (19. Torsion of Shaft with Keyway. Get a quote +61 7 3271 5424. 376 . Standard tolerancing on stainless. = 0 °F. About Keyway Broach Tools. The key length should be less than 1. Keyway Depth (Normally 1/2 of width) Total Height (X) = Depth (Y) = Metric Calculator Bore Size. n Non-standard bores available – consult Lovejoy Engineering. For example, if the gear ratio was 1. A tolerance given that defines how far from a perfect line a feature can be. Bores with closer tolerances will be supplied at a slight increase in price. But to calculate the normal tooth force and its radial component correctly, the effective pressure angle, not the nominal profile angle, must be used. See dimensions W and h in Figure 1. 8 14 9 51 58 16 4. TECHNICAL DATA TOLERANCES OF REGULARLY USED HOLE FITS 1999. Minimum keyseat width is that figure permitting the largest shaft. $1. - Calculate the dimension for programming the depth of the keyseats. Wall Thickness and Ejector Marks Tolerance Calculator Grade E. 000-0. Machining Tolerances Calculator - Technical Help. Ultimate tensile strength 580MPa, Yield stress approx 300 MPa. Keyway Width. Standard Bore Tolerances 1" and Less + . Book Store Engineering Forum Excel App. Lock nuts with integral locking . P9. 342 Minimum 3. 1 Square Keyway Tolerances. clearance fit bores with set screws. TECHNICAL DATA TOLERANCES OF REGULARLY USED HOLE FITS 1999. ; Spur Gear Train Backlash Review Spur gear backlash is the amount of tooth space between. ) and. Shaft Diameter Recommended Key Size; 0. , 1957, “When splines need stress control. 13. Volume can be accurately specified with size deviation and geometric tolerance deviation, which caters to appropriate tolerance establishment. Considering the positive sides, there is no need for cutting the keyway or making a spline on the shaft and housing which is a costly affair, moreover, there is no stress concentration. BOTTOM OF SHAFT TO BOTTOM OF KEYWAY. Engineered products . Enter the precision grades of the two gears as well as absence or existence of tooth form correction (s). 10 Buy. n When referencing the Lovejoy UPC number in this table, include 685144 as a prefix to the number shown. The letter designation in the code H7 establishes how far away the maximum shaft or minimum bore tolerance is from the nominal dimension. 00 ± (B) Tolerance values Figure 4. 1 0 : 5×5 Keyway Connection. 8 6 6 23 30 8 3. 5020 2. 1L, 2L, 3L, 4L and 5L are designed with a shaft extension without a keyway. 0005" tolerance and a not parallel to bore tolerance which creates a feeling of tighter fit. - Calculate the dimension for measurement of the keyseats. Select the Material. 0 for severe vibrations/shocks. I have a base plate with a keyway and some holes. Our Online Calculator streamlines this process and provides a detailed final result immediately. ex: H11. By exploring the title, publisher, or authors of guide you in in fact want, you can explore them. 4 Notes on dimension sheets Scope of delivery Tolerances Shaft heights The following tolerances apply to the indicated dimensions: Foot-mounted gear units: Check the mounted motor because it may project below the mounting surface. Keyway metric dimensions key iso tolerance js9 r773 width per depth hub t2 height radius text mill question answered hasn Keyway chart Shaft and hub keyway dimensions Keyway hallite. Download the Machinist's Calculator trial. If the shaft and bore shift in opposite directions, you need to account for that. In other words, a gage may not accept a bad part, but it can reject a marginally good part. This is a ± band clearance where the value of the tolerance is equally oversized or undersized. ISO Tolerances for Shafts (ISO 286-2) ISO Tolerances for Shafts (ISO 286-2) Nominal Shaft Sizes (mm) over. 4 18 11 66 75 20 4. Tolerance of ± 0. Standard External Metric Thread and Fastener Sizes M 0. ISO and ANSI Standards. Keyway is a recess in the shaft and hub to accommodate the shaft key. Where standard ends do not satisfy the application requirements, special ends may be machined to customer specifications. Keyway Depth. Grainger approved keyed shaft,dia 1-1/4 in,keyway 1/4 inShaft keyway shear and yield strength formulae and calculator Splines keyways keys key keyway shaft milling machine componentKey and keyway dimensions (control in motion). 1 standard which is based on inch units. Max. 1 standard defines a system of preferred fits only for basic sizes up to 19. 1-1967, ASME standard B17. AGMA 9002-A86 Inch Bore and ANSI B17. Rectangular sunk key. Dimensions and tolerances for metric ISO thread with 60 degree flank angle are included in the DIN 13 standard. 001) of an inch. 1. 2 Tolerance of a basic size for specific tolerance grade. Square keys. 00 deg (with an angular tolerance dependent on how you interpret the drawing) The location of the center of the bolt circle: x = 4. This standard also gives the manufacturing. The following are definitions for the elements: Offset (X) - This is the difference between the basic dimension (Drawing) and the actual measurement of the produced part. Keyway chartStandard keyway dimensions Keyway calculator shaft depthKeyway-and-key-size-dimensions. Z = ( D / 2 ) cot ( α / 2) α = countersink angle. 3) Keyway fillet radius to be specified by customer. 2180 Corporate Lane, Suite 104 ~ Naperville, IL 60563 USA Phone (630) 596-9000 Fax (630) 596-9002 E-mail: [email protected] times the shaft diameter to ensure a good load distribution over the entire key length when the shaft loaded in torsion. Identifies two or more separate features that should be treated as one such as two planes separated by a keyway. Over To (Incl. To achieve this, HORN combines cutting-edge technology, performance and reliability. 006″The hub keyway is dimensioned by its width and depth on the shaft – keyway sides. A surface roughness comparator chart can be used to compare the filed surface to 6 3 247 0 N9 12 5 485 The tolerance represents the total amount by which. The following tables report the preferred metric fits and tolerances for hole and shaft basis systems given by the ISO 286-1 (2010) and ANSI B4. ANSI-B17. 093 / . Metric Keyways Dimensions ISO/R773. 4990” plus . i have had more problems with internal keyway not parallel to bore more than . C is the conductivity of the material. ISO Bore Tolerance Chart For bore tolerance system, Nominal sizes from 1 - 160mm DIN 7160 (8. Hollow structural section (HSS) design for strength I beam design for strength Linear thermal expansion Stress strain calculator Thermal stress in a bar Thermal stress in a uniform plate Rectangular beam design for strength Stresses in rotating rings (Annular disks) Torsion of solid and hollow shafts. pdf New year, new designs tips. Unless otherwise specified, the shaft keyway is assumed to be standard. A shaft key is a small metallic component mounted between the shaft and hub to restrict the relative motion. ISO TOLERANCES FOR METRIC FASTENERS Hobson. Keyway Calculator *tweaked* - just enter diameter of shaft (or bore)! DMF_TomB, I took your calculator you posted, added some more graphical info and tweaked a bit, so it automatically looks up the standard keyway for any given diameter shaft or bore and adds everything (again, automatically) to the graphic. 095 . 7530 3. 005, y = 3. 99. R =. 3mm 3. Keyway Js9 Tolerance Chart Keyway Js9 Tolerance Chart You have stayed in right site to begin getting this facts. Torque Applied Deformation and Stress of a Shaft with Keyway Equations and Calculator. 0 Table of Metric Shaft Tolerances per. txt) or read online for free. 'keyway tolerances Mechanical engineering other topics May 12th, 2018 - For shafts 10 to 22mm. 003 (100-0~015)10~005 (2001-0~099)+0~002 25. Thus, a 5mm depth will be optimal for this assembly. 3 5 5 18 22 6 2. To secure the hub and shaft and stop relative movement between a power transmitting shaft and an attached component, a key and the keyway combine to form a keyed joint. Calculator for designing shaft keys Shaft diameter d mm Shaft torque T Nm Key length L mm key width b mm key height h mm keyway depth shaft t 1 mm keyway depth hub t 2 mm shear force F s = T/ (d/2) kN shear stress key τ = F s / (L搓) MPa bearing pressure p = F s / (h/2 微) MPa Nominal torsional stress τ = T/ ( π/16搞 k3 ), d k =d-t 1 MPa 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. Page 6 of 6. 975-0. 000 -0. If the technician installed a key that measured 8″ long × ¾” × ¾” and then mounted the coupling onto the shaft it would result in an excessive key length sticking out past the back edge of the coupling hub. Rectangular sunk key. You do get an implied symmetry to the central axis. 5. “Learning GD&T From Scratch,” provided by KEYENCE, walks you. Beam Calculator. 001 - . Metric Key Keyway Dimensions. Rexnord Industries, LLC, Coupling Group 427-108 5555 S. The schematic representation of the fit is also. Assuming iso since you used mm. Pressure Vessel Pumps Applications Re-Bar Shapes Apps Section Properties Apps Strength of Materials Spring Design Apps Structural Shapes Threads & Torque Calcs Thermodynamics Physics Vibration Engineering Videos Design Manufacture Volume of Solids Calculators Welding. txt) or read online for free. Using the minimum diameter of the hole as the. Check Details. You can print out and. As with all functions of the Machinist's Calculator, linear values can be. The prole keyway is cut by an end-mile while the sled-runner keyway is cut by an ordinary milling cutter. If you dimensions a keyway per iso standards. KeyWay /Key Dimensions. 015"/-0. Keyways Index. - Calculate the dimension for measurement of the keyseats. The following Engineering calculator will show the plus and minus tolerance for the specific ISO 286 hole tolerance data. ISO 286 establishes common manufacturing tolerance classes. 5^circ θ = 80. Figure 3. ISO Tolerance Calculator (Explained) Our tool is a fit/tolerance calculator that is addressed to students, employees, and apprentices (trainees) in all technical sectors. DIN 6885 Keyway, key details Extract Page 1 heavy type d b P9 / JS9 Hub keyway b P9 / N9 Shaft keyway h t 1 = d + t 2 t 2 t 3 = d – t 4 t 4 6 2 2 2 7 1 +0,1 4,8 1,2. 5 1 6 2, 6 2 2 2 4 3 3 3. Load factor can range from 1. The dimension from the top of the keyway to the opposite bore side, “T-dim”, is calculated from (refer to ANSI/AGMA 9002-B04) the following: T = bore + (h kw -. Non standard bores and over the keyways. 000 1 1/16" to 2" + . We also have an Imperial Keyway Calculator. Find the depths to cut in keyway and keyseat. Precision lock nuts . 1 -1967 (2004) standards for metric and inch unit systems. Nearly every shaft diameter has a corresponding standard keyway width and depth – this calculator helps you find it. n Non-standard bores available – consult Lovejoy Engineering. Wall Thickness and Ejector Marks Tolerance Calculator Grade E. There is quite a lot of detail around this topic in Machinery's Handbook, including proper depths and tolerances. In this calculation a shaft of length L, diameter D, with keyway dimensions K × H is considered. 4mm 8mm 2mm 9mm 12mm 11mm 4mm 4mm 14mm 15mm DIN 7154, H7 Metric Bore and DIN 6885, Js9 Square Keyway Tolerances Page 1 of 4 Tolerance b Hub keyway b Shaft keyway for tight fit P9 P9 for loose fit JS9 N9 for sliding D10 H9. The schematic representation of the fit is also drawn by tolerance calculator. , New Berlin, WI 53151-7953 March 2015 (PDF. The first principle to grasp is the fit designation of the shaft /hole joint. We call this shape a keyway. KeyWay /Key Dimensions. Surface Finish — Sides and bottom of keyways shall not exceed 250 micro inches. • Keys DIN 6885 → Page 842. Metric thread size and tolerance calculator was developed to calculate major minor and pitch diameters of the external bolt and internal nut metric threads according to ISO 724 1993 standard. Shear and Torque Equations and Calculator. There is also a calculator to calculate the press fit force, required temperatures for shrink fit, fit stresses and other parameters necessary for. Keyway broaching on CNC lathes offers several advantages over traditional broaching machines: Flexibility: Indexable inserts allow for a great flexibility with various tolerances (such as H7, JS9, P6, D10, C11) and profiles (square, hexagon, spline) at a relatively low cost. D. Enter your desired preferred tolerance grade and the nomial size. To broadly and briefly touch on bore and keyway standards, the North American (inch/imperial) standards tend to be more straight forward with limited variation (derived off the shaft). Keyway width P9 tight fit (standard design) JS9 or N9 loose fit (requires written agreement) see also. 4990”- . To confirm the status of any standard, identify the replacement standard if it is obsolete and/or purchase the standard please use. 7MB installed)14 Catalog – DT/DV-GM2009 2 Notes on dimension sheets Important Information, Tables and Dimension Sheets 2. The minimum bonus tolerance is zero, and the maximum is the tolerance field of the feature’s size. Check out this Dowel Pin Slip Fit Tolerance Chart for further consideration on slip fit tolerances. A square key is used if the deeper key depth is required to transmit torque. iso keyway tolerances p9 orientation sutd edu sg web keyway tolerances mechanical engineering other topics may 4th 2018 can anyone advise what tolerance class should be used on. All internal calculations are done using metric millimeters. S. 2018 Standard ASME vs ISO GD&T. ISO/R 773:1969. Shaft Keyway Shear and Yield Strength Requirements Formula and Calculator. 2-1967. 25 - M 1. Nearly every shaft diameter has a corresponding standard keyway width and depth – this calculator helps you find it. 26 Representing Tolerance Values Tolerances are represented as direct limits or as tolerance values. Download: Keyway & Tolerances Calculator APK (App) - Latest Version: Metric + Tablets - Updated: 2023 - com. Just select DIN 743 for drive shafts, DIN 6892 or DIN 6885 for parallel keys. Manufacturing will be based upon DIN 6885 - T1. From the right side of the shaft total diameter is given with tolerances. The keyway dimensions are also different from the English system. 469 Minimum 3. Woodruff key is a flat semi-circular or half-moon-shaped disk with a uniform thickness, which directly fits into the semi-circular recess of the shaft. Coping with foreign bore and keyway standards Machine Design. A key of 8 mmx 7mm by 70mm long is selected. 001" (. 246=0. The advantage of the Js9 tolerance is that the key can be inserted and the gear manipulated without much difficulty. The advantage of the Js9 tolerance is that the key can be inserted and the Keyway Bore (inches) Reference Height (d) 1. The first principle to grasp is the fit designation of the shaft /hole joint. Keyway Calculator. 0001” tolerance and the No Go would be specified as . 003 - . The. Related: Standard Metric Keys and Keyway Bores. 002″ The MMC is 0. The maximum shear stress occurs at the outer radius of the coupling and at the interface of the two bores. The calculator has been tested, but no guarantee can be given for the accuracy of the results. 01 mm can be obtained between surfaces being cut simultaneously. (Dimensions comply with DIN 6885/1) †† Requires use of chamfered keys. Select the Woodruff Cutter from the tool menu (Note: Keyseat cutters are referred to as Woodruff cutters for feeds and speeds):Example: Using the taper calculator. Identify the tolerance requirement limits where manufacturing or performance of the final system are adversely impacted. ISO Tolerance zone Calculator Theoretical Machinist. Allowance must be made for keyway and setscrews . 2 continued. N = Number of splines. The first is Js9. Welcome to HORN. The full definition of composite tolerances can be found in section 10. a) End-milled or prole keyway b) Sled-runner keyway. Fit Charts. The profile of a straight sided spline is defined by. The hole basis fits have four preferred hole tolerances (H11, H9, H8, and H7); the shaft basis fits have four preferred shaft tolerances (h11, h9, h7, and h6) as shown in Table 6-1. To broadly and briefly touch on bore and keyway standards, the North American (inch/imperial) standards tend to be more straight forward with limited variation (derived off the shaft). It calculates upper limit, lower limit, maximum diameter, minimum diameter and range by simply entering a basic size and selecting the desired tolerance (DIN EN ISO 286 norm). and Canada) +1 781-373-6808 (International number) Forsale Lander. The gap of the keyway is shown with tolerances again and the semi-gap is shown. ISO Hardware Specifications Table. Shaft keysKeyway shaft roymech tolerance Keyway size chart. D o: Assuming a basic shaft size of 25mm . 5000 2. Assuming iso since you used mm. The True Position is the exact coordinate, or location defined by basic dimensions or other means that represents the nominal value. Merely said, the Iso Keyway Tolerances P9 Pdf is universally compatible when any devices to read. Undersized. Easily calculate the values required to cut keyseats and keyways. 10 e. 1875 0. 65) Nominal dimension Tolerance Zones over to U7 S7 R7 P7 P9 N7 N9 M7 K7 J7 JS9 H7 H8 H11 G7 F7 F8 E8 E9 D10 deviations in µm 1 3 -18 -14 -10 -6 -6 -4 -4 -2 0 +4 +12. This is an intuitive concept to grasp- a clearance fit specifies a fit where there will always be a gap in the joint between the mating shaft and hole. Add to wishlist. 5580. Underconstrained + Maximum Material. We also have an Metric Keyway Calculator. 1 -0. It is noted that this is equivalent to a stress concentration factor of 1. keyways available upon request. As noted above, when selecting a keyway tolerance, there are two common selections in the metric system. The second is a P9 tolerance. O Øo. com Bushing chart weight bushings steel npt Metric keyway tolerance chart. 250 +0. Finished Striaght bores for standard AGMA Class 1 Clearance fit. KeyWay. The full definition of composite tolerances can be found in section 10. MPTA B1c – Bore and Keyway Tolerances for V-Belted Sheaves (MPTA-B1c-2010) This standard defines the bore and keyway tolerances to be used for V-belted sheaves. P9 and D10 width tolerance can be furnished on request. So I made it myself. js9 width Metric keyway sizes. 3mm 2. 1265 0. Two PDFs with useful engineering data on keyway sizes and engineering limits and fits, just download. Key. 8. The usual proportions of this key are : Width of key, w = d / 4 ; and thickness of key, t = 2. 3 5 5 18 22 6 2. - Series F couplings supplied with 4) All dimensions per AGMA 9002-A86 interference fit bores without set screws commercial standards. The relative position of the holes is. The commonEngineering Fits. 1 Square Keyway Tolerances . 2 (1978) and ANSI B4. fits and tolerance calculator iso system amesweb web iso 286 establishes a system for tolerances to be. A tolerance is described using a letter followed by a number. Loose running fit for wide commercial tolerances or allowances on external members. Bonus Tolerance Example: Let’s look at a bore of 1/4″ +/- 0. 1. Design of Square Key and Keyway (Wood Ruff) Stress, Shear and Torque. 360 Minimum 2. All the tolerance for the gage comes from the tolerance for the part. 3 10 8 39 44 12 3. 5 Pin and Ring Gauges ; ISO Tolerances For Fasteners ; Gauge Blocks Tolerances Specifications Table DIN 861 ; General Tolerances Shaft - Holes Fits ; GD&T Geometric Dimensioning Tolerancing Basics Training ; GD&T Geometric Dimensioning Tolerancing Intermediate Training ; GDT ASME Y14. Keyway metric dimensions keys. pdf), Text File (. An example for a straight-sided spline is shown (Fig. A tolerance is described using a letter followed by a number. 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. In other words, a gage may not accept a bad part, but it can reject a marginally good part. 005) Tolerance Stack-upKey stock, or bright steel, is a general term for a stock of square or rectangular bars 12 inches or longer in length from which machine keys are produced. The bolt hole pattern: 6 x 60. Moorland Rd. 19-1997; Design of Square Key and Keyway (Wood Ruff) Stress, Shear and Torque; Metric Key Keyway Dimensions Based on standard tolerances and limit deviations in accordance with ISO 286. As in the example above, this requires looking at part alignment and specifying tolerances referencing fit and function. 24+ keyway depth calculator. It contains the definitions of these terms as they apply to elastomeric couplings. The letter is the tolerance deviation, the number the tolerance grade. 4. Select the Machine. 493. This enables the use of standard gages.