1. Engineers Black Book - Hot Sheet E25. 2-1967. keyways, respectiveiy in the hub and in the shaft. This cylinder has two 3/32” diameter ball bearings on each side of the keyway. Download. C +0. Shaft with Two Keyways Torque Applied Deformation and Stress Equations and Calculator. Durometer 85D. The position of keyways should be specified within inner dimension (L-F-S) of a retaining ring. 4- Some internal Grade values must be rounded down to a precision of 3 decimal metric millimeter precision. LOOSE RUNNING: Fit for wide commercial tolerances. Parallel keysKeyway shaft roymech tolerance Shaft standard key sizes rectangular gates keys diameters most non std readily availableParallel metric keys and keyway dimensions. No external keyStandard Keyway Dimensions Shaft Diameter Set Screw Width Depth Up through 7/16" 8-32 3/32 3/64. BS 46 Part 1 : 1958 Square Keys and keyway Dimensions. 125 32 7,4 125 125 125. 6. Depth values for shaft keyseats - hub keyways Fit tolerances for parallel and taper keys Gib head dimensions for taper keys Key size versus shaft diameter Set screws for use over keys Parallel and taper key dimensions and tolerances Woodruff key sizes and dimensions Woodruff keyeat dimensionsThe following ISO Tolerance Chart for bolts and holes per ISO 286. com ©2004-2021 Kramer Power Equipment Co. 2) Dimension h of the taper key names the largest height of the key, and dimension t z largest depth of the hub keyway. The semi-circular recess or pocket is known as the woodruff keyway. H is the key height. Tolerances and fits peculiar to broach cutting tools require extra thought. ANSI-B17. A key is a machine element used to connect a rotating machine element to a shaft. In order to avoid stress concentration, leave radii on the keyway corners. Over 1000 to 2000 incl. 5 m (500 mm) Lengths (19. A tolerance is described using a letter followed by a number. ISO/TC 14. The 10% Rule is intended to assist in the selection of the tolerance for Go & No-Go gages. 19-1997 ; Keyway Stresses for Non-metallic Gears and Shafts Formulas and Calculator; Shaft (Arbor) Keyway Dimensionl Data - ANSI/ASME B94. Dimensioning and Measurement of a Key Way [ 1] •. 'Keyway Tolerance Chart PDF documents docucu archive com April 21st, 2018 - Keyway tolerance chart PDF results Shaft Do not scale metric din 6885 1 c js9 keyway all dimensions are in mm set screw length øa depth 10 4 11 4 12 8 13''Keyway Dimensions Armstrong MetalcraftsWhen a keyway is damaged, cut a new, wider one. ISO 286The parallel tolerance is tighter than symmetry. Keys and Keyways: Dimension charts for Keys and Keyways: Limits, fits and tolerances calculators: Calculates the limits, fits and tolerances according to ISO 286(2010), ANSI B4. 000 / +. A Keyway is a slot of some kind that is used to align the part on a shaft and prevent the part slipping as the shaft rotates. 1 -0. Unless otherwise specified, the shaft keyway is assumed to be standard. eg. The minimum bonus tolerance is zero, and the maximum is the tolerance field of the feature’s size. English Dimensions: Keyway: W x T Key: W x T Metric Dimensions: Keyway: W x h Key: W x T Common dimension specificationBore tolerances per BS 4500 H7 fit. 25 m (250 mm) Lengths (9. keyways available upon request. 02 0. keyways /keys dimension in accordance with BS 4235-1:1972: Specification for metric keys and keyways - Parallel and taper keys. 5 times the shaft diameter to ensure a good load distribution over the entire key length when the shaft becomes twisted when loaded in torsion. 6 - M 18. Also calculated are the overall measurements for shaft and bore, as well as the chord height. This is an undersized clearance. 7500 3. Preferred tolerance grade ISO 286; International Tolerance GradesFor a solid steel shaft of 18mm diameter, with keyway 6 wide x 32 long by 3. Moorland Rd. Shaft Outer Diameter Width Height Depth. 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. Semi-circular pocket in the shaft directly cut by woodruff key cutter. 438 . Created Date:tolerances, poor installation practices, thermal growth or shrinkage, foundation movement, and/or component wear. Tolerances are used to control the amount of variation inherent in all manufactured parts. ex: H11. Standard. this one. 99. Preferred tolerance grade ISO 286; International Tolerance Grades For a solid steel shaft of 18mm diameter, with keyway 6 wide x 32 long by 3. 001 mm ) d9-20 -45Open ISO 286 Table of Shaft Tolerances Calculator. 8 38. 35 9. 3 10 8 39 44 12 3. DIN 6885/2 Keyways d b P9/JS9 Hub keyway b P9/N9 Shaft keyway h t1 = d + t2 t2 t3 = d - t4 t4 11 4 4 4 12. 469 Minimum 3. DIN 174. As noted above, when selecting a keyway tolerance, there are two common selections in the metric system. A list of standard keyway and corresponding key sizes for English shafts are listed below in Table 1. The True Position is the exact coordinate, or location defined by basic dimensions or other means that represents the nominal value. T Metric trapezoidal thread, 7H: ISO 2903 Axial run-out locating face/thread: 0,06 to 0,16 mm max. This may also be written in this standard are intended for single key appli- a s shaft keyseat or hub keyseat when describing cations only. 8 14 9 51 58 16 4. Each tolerance has a maximum and minimum. 6 or below. ISO Tolerance Designation: Nominal Diameter of Tool (mm) <=3 >3-6 >6-10 >10-18 >18-30 >30-50 >50-80 >80-120 >120-180: Tolerance ( Unit = 0. REFERENCE DEPTH. js9 width Metric keyway sizes. web keyway js9 tolerance chart the keyway broaches made of hss in tolerancejs9 p9 h9 according to din 6885 are furnished with shims and for the use on materials up to hrc30 br285 tolerances h11 h9 h7 and h6 as shown in table 6 1rpm at the motor base speed . Check Details. 1-1943 Standard. 4. 004″ with the below true position callout of 0. Only the range of key lengths and dimensions of keyways differed for machine tool applications. W = d/4[clarification needed] H = 2d/3[clarification needed] where. Keyway chart shaft sizing engineeringKeyway sizing chart Agma keyway bores engineers edge asa data fit llc copyright 2000 2021Keyway dimensions table aii. 039 mm. The fit designation ranges from clearance fits to interference fits. Check hubs, shafts, and keyways for burrs. 000 on the keyway) at the max key and min keyway you have a problem and the components are not going to fit and that is why his proposing 0. Mm Shaft Diameter Groove dimensions for woodruff keys DIN 6888. Subscribe. 625 / . T Metric trapezoidal thread, 7H: ISO 2903 Axial run-out locating face/thread: 0,06 to 0,16 mm max. broached internal keyway possibly has larger than . 1/16" 3/32". Keyway Depth Keyway Radius Hub "T2" Max "R. Shallow keyway depths must exceed 2/3 of the full keyway depth of the square keys shown above. • Describe the profile of a surface tolerance. Shafts outside the listed range may present trouble with installation. Key and keyway dimensions (Control in Motion) Check Details. General tolerances 21Food. manufacturing tolerances, preferred fits and tolerances charts iso, din 6885 stainless steel keys stamel ro, parallel metric keys and keyway dimensions,. Tolerance Rating. 030 0 +0. Standard and metric keyway broachesKeyway sizing chart Standard keyway dimensionsKeyway sizing chart. Table of Metric Shaft Tolerances per. SLIDING FIT: Not intended to run freely, but to move and turn and locate accurately. Since they fit more loosely than standard keys, these undersized keys are best for uneven keyways or when you need to disassemble parts. 0. D. 535. Check Details. Useful Data On Limits & Fits and Keyway Sizes - TNN Engineering. Keyway Cutter Hole Keyway Dimensional Data for MIlling Centers and Arbors - ANSI/ASME B94. 3 6. The shaft keyway and hub keyway dimensions according to ISO 6887 - taper keys with gib head - are equal to those in ISO 6886 used for cutting tools, material stock, gages, etc. 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. Detailed width tolerance information is best drawn from the manufacturer. Oversized. To confirm the status of any standard, identify the replacement standard if it is obsolete and/or purchase the standard please use. The profile of a straight sided spline is defined by. 5 +0. TOLERANCES ISO. 493. 000-0. I -I w*l-8-4 GIB HEAD TAPER Over I I. ). The first set indicates the pitch diameter tolerance, and the second set indicates the major diameter tolerance. Question: Metric Key Keyway Dimensions Per ISO/R773. WIDTH. Re-design the shaft shown below to be a uniform,Metric woodruff keys are supplied to din 6888 / iso 3912 in c45k key All torque transmissions resourcesKeyway chart bore resources torque alltorquetransmissions. 3 Cross section of keyway r2 b2 r2 b1 b2 r1 b1 S2. 000 / +0. Rockwell B87. 0005 / -. 90. The symmetry tolerance does two things to the keyway; sets a tolerance for the keyway to be offcenter as well as tolerancing the width. 625″ OD, For Split Taper Sprockets & Sheaves. RC - Running or Sliding Fits ; LC - Clearance Locational Fits ; LT - Transition Locational Fits ;Along with keyway size tolerances and keyway depth sizes, some standards also provide information on the recommended key size and keyway depth as a function of shaft diameter. Metric External Table Chart Thread Designations Sizes M 1. LOCATION FIT: Snug fit for staitonary parts, can. The hub keyway is dimensioned by its width and depth on the shaft – keyway sides. Add to Cart. The following tables show standard dimensions for keys and their grooves. web keyway js9 tolerance chart the keyway broaches made of hss in tolerancejs9 p9 h9 according to din 6885 are furnished with shims and for the use on24mm Bore, 8mm Keyway Width x 3. 1 Size Shaft Dia. Metric Key & Keyway Dimensions Per. Max. ANSI-B17. Keyseat Alignment Tolerances: A tolerance of 0. Whereas the P9 tolerance is a press fit tolerance. A keyed joint is used to ensure orientation or restrict rotational movement between parts, as in the case of joining a shaft with a coupling. 00 tolerance 2. Straight-sided splines for cylindrical shafts with internal centering — Dimensions, tolerances and verification. Tolerances and resultant fits SKF com. DIN 6887. pdf New year, new designs tips. Type: Refer to page 3 and select the appropriate coupling type . Insert Arrangements Shell Size Designator Insert Arrangement. A Key goes into the Keyway to lock things up. British Standard Metric Keyways for Square and Rectangular Parallel Keys 11 5/16 3/8 7/16 1/2 3/4 3/4 7/8 Nominal Diameter, d 6 1/2 7 1/2 9 Square Keys preferred for shaft diameters above this line: rectangular keys, below Key 3 3/4 4 1/2 5 1/2 Shaft Key Size Versus Shaft Diameter ANSI B17. Keyway key parallel jis sizes tolerances 1301 mm 1996 pulley excerpt unit techKeyway metric Table aii-12. This online message KeywayKey/Keyway Positions Master Keyway 105° 140° 215° 265° 140° 215° 265° 60° 105° Master Polarizing Key Master Keyway 105° 140° 215° 265° 140° 215° 265° 60° 105° Master Polarizing Key Receptacle Plug Note 1: Shielded, not applicable to Series II or hermetic connectors. Another name for a Keyway is a Keyseat, since the Key is seated in the Keyseat. Unless otherwise specified, the shaft keyway is assumed to be standard. If held to these tolerances, cutting tools, material stock, and gages are generally available throughout the world. 4375 1. Each tolerance has a maximum and minimum. . Keyway (Shaft. 44 / ea. Rockwell B85. 093 / . The table, to the best of our knowledge, complies with:. Loose running fit for wide commercial tolerances or allowances on. MIKI PULLEY Clutch and Brake Standard Hole Drilling Standards. 000. Because this tolerance is looser, fabricators can secure it by hand. 2 +0. We additionally allow variant types and in addition. 000 / +0. Use them in light duty applications to connect gears and other components to shafts. Fit Types. 1. Square Keyway Tolerances Page 1 of 4. 1 +0. For example, a gear located on a shaft might require an The attached data sheet of Selected ISO Fits shows the range of fits derived from these tolerances and covers a range, from loose clearance to heavy. 0640 0. MPTA B2c -Standard Practice Sheave / Pulley Balancing (MPTA-B2c-2017). Hole-Drilling , Tolerances , Fitting. 74By correctly interpreting which standard a PT component was made to, you can solve replacement specification problems and eliminate expensive special ordersNumber of keyways are selectable up to 3. Metric bore tolerances conform to ISO 286-2 H7 for clearance fit and P7 for interference fit. radius. The first is Js9. Cut keys to custom lengths. 3. • Explain the circularity tolerance. Undersized keys are good when you need a slightly looser fit or when you have an inconsistent keyway. d. 000/2. It is not economical to “over-tolerance” a feature that does not require it. Standard and metric keyway broachesTable aii-12. 5 +10 +14 +60 +12 +16 +20 +28 +39 +60 Keyway dimensionsKeyway sizing chart Metric stepper motor shafts size data tableMetric key keyway dimensions per iso/rtt3 js9 width. WIDTH. KEY DIMENSIONS AND TOLERANCES ;El PARALLEL t. AA dimensions shown in chart are Baldor typical values meeting or exceeding NEMA. Check Details. Bore Size Identification System. 3mm 3. ISO Tolerances for Shafts (ISO 286-2) Nominal Shaft Sizes (mm) over. Quantity. ISO/TC 14. BS 4235-2:1977, ISO 3912-1977: Specification for metric keys and keyways - Woodruff keys and keyways. Keyway Width "D" Nominal. clearance fit bores with set screws. Ok! You're unsubscribed. js9 width. As with all functions of the Machinist's Calculator, linear values can be. , depending on the lock nut size Mounting slots according to DIN 981 HM/HME and HM . 6 - 8 - 10 - 12 - 14 - 16 - 18 - 20 - 22 - 25 - 28 - 32. The usual proportions of this key are : Width of key, w = d / 4 ; and thickness of key, t = 2. Keyway (Hub) Radius r. AGMA ASA Keyway and Bore Design Data ASA Keyway and Bores Design Data including dimension; Woodruff Keys ANSI B17. The bushing system described in this standard is limited to systems having the following characteristics:. Positional tolerances is used to locate features of size from datum planes such as a hole or keyway and used to locate features coaxial to a datum axis. Recommended ANSI Standard Keys and Keyseats Design per. Only informative sections of standards are publicly available. web keyway js9 tolerance chart the keyway broaches made of hss in tolerancejs9 p9 h9 according to din 6885 are furnished with shims and for the use on materials up to hrc30 br285Metric Keyway Broaches High Speed Steel & TiN Coated Keyway Width (mm) Broach Dimensions (Inch) Standard Keys (mm) No. 10. imperial keyways diameter key size (nominal) shaft hub width depth width depth over incl w h max min max min max min max min 25. Web Price. 4. You can read about them here. Fits and tolerance calculator for shaft and hole tolerance calculation according to ISO 286-1 and ANSI B4. 002" / - 0. dimensions. The hub keyway is dimensioned by its width and depth on the shaft – keyway sides. This page explains the advantages and disadvantages of using these instruments. Width. For Hub Keyway Height. 587 / 2. This is a ± band clearance where the value of the tolerance is equally oversized or undersized. BS 5686:1986, ISO 14-1982: Specification for straight-sided splines for cylindrical shafts: metric nominal dimensions, tolerances and gauging requirements. Page 1420 | Modi˜cation standads 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 +0,1 The hub keyway is dimensioned by its width and depth on the shaft – keyway sides. T = 393. Over 400 to 1000 incl. Design of Square Key and Keyway (Wood Ruff) Stress, Shear and Torque. i always thought internal keyway should be within . We would like to show you a description here but the site won’t allow us. 5 times the shaft diameter to ensure a good load distribution over the entire key length when the shaft becomes twisted when loaded in torsion. Size and tolerance, Radius required in keyway, Location tolerance of keyway respective to bore and other keyways) Types of Interface Information Required for Bolted Joints 1. 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. (1) d b1 b2 b1. The basic size of the feature or fit is the dimension the tolerances will be applied to: The zero line in the calculator. Table 1 details the appropriate key slot and key sizes for various. Durometer 85D. Home. Rockwell B82. - The maximum tolerance describes the. 05 FSO 600/2. 5-2009 standard has defined. 7500 3. Slip fit tolerances are ideal for when the part needs to functionally slide (e. Table 1 details the appropriate key slot and key sizes for various. The upper surface must be located within two parallel planes at a tolerance value of 0. 3/32" 1/8" 3/16" 1/4" 5/16" 3/8" 1/2" For Shaft Keyway Height. Chart shown later in this document gives the number of threads/inch based upon threads series and nominal diameter. The standard tolerance for the hole of grade 8 (IT8)= 25 i= 25 × 0. 2. 40. 99. james. a spline for a 50mm OD spline with say a module of 2mm would have a PCD (D) of 50 - 2 = 48mm. 4235 : PART 1 : 1972Keyway Cutter Hole Keyway Dimensional Data for MIlling Centers and Arbors - ANSI/ASME B94. 90. 3 12 8 45 50 14 3. Shaft Key Seat Depth Control Values S and T for Shaft and Hub ANSI B17. If held to these tolerances, cutting tools, material stock, and gages are generally available throughout the world. 1 Square Keyway Tolerances. If a press fit is necessary, never exceed . 020: 0. ISO Tolerances for Shafts (ISO 286-2) Nominal Shaft Sizes (mm) over. keyway js9 tolerance chart secure4 khronos web may 21 2023 the same and is only listed. 000. Keyway metricStandard and metric keyway broaches Keyway chart pdfKeyway metric dimensions key iso tolerance js9 width r773 engineering depth hub t2 per mechanical height text radius nominal mill. The tolerance band is the region between two parallel planes at a distance of tolerance value t. 1 0 : 5×5 In October’s column, I mentioned the typical tolerance for key- ways. the spline connection, then major diameter transition fit (or interference fit) according to ISO (outside shaft diameter toler-ance H7 and major internal diameter tolerance n7 (or H7/p7These pockets in shafts are directly cut by using woodruff keyway cutters. You can check the tolerance chart below: Table 4 - General Tolerances on Straightness and Flatness Ranges of nominal lengths in mm Tolerance Class H K L up to 10 0. You will also find. Shaft Diameter. All internal calculations are done using metric millimeters. BS 46 Part 1 : 1958 Square Keys and keyway Dimensions. 8. Don’t forget that the world-famous All Torque Transmissions keyway chart is available on our website. clearance. Reference AGMA 9002-B04 IMPERIAL METRIC NOMINAL KEYWAY KEYWAY DEPTH MEASURED AT CENTER Metric Standard Bore and Keyway Info Recommended Bore. 180. 062 0. Width Tolerance Height Tolerance + 0. Subscribe. The first is Js9. 8mm 2. Since they fit more loosely than standard keys, these undersized keys are best for uneven keyways or when you need to disassemble. May 13th, 2019 - Square Keyway Tolerances 3 8 3750 7 16 4375 Page 1 of 6 PFEIFER INDUSTRIES LLC 2180 Corporate Lane Suite 104 Naperville IL 60563 USA Maximum 1 6885 0 3770 1 869. 4235 : PART 1 : 1972 Imperial – Rectangular B. Lovejoy supplies ‘metric’ dimensioned ‘F’ hub straight bores with bore and keyway tolerances conforming to the ISO 286-2 standards for a P7 interference fit unless otherwise specified. The Y14. tolerances. The ball bearings are not spring loaded and are not staked into place in the plug. 9 20 12 76 86. Tolerance is the total amount a dimension may vary and is the difference between the upper (maximum) and lower (minimum) limits. Top. 90 edition Tolerance zones shown forTolerance zones shown for nominal dimension 60 mm ISO abbrev. 062 0. 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. 1-1967 or JIS B 1301-1996 specify sizes and tolerances of the keys and keyways. . Free running fit not for use where accuracy is essential, but good for large. These keys have a rounded shape that makes them easy to remove when parts need to be taken apart frequently. Keys are made of steel. ASME B1. 3) Keyway fillet radius to be specified by customer. Customer Service. 1265 0. 3mm 5mm 5mm 5mm 5mm 6mm 6mm 6mm 8mm 8mm 22mm 24mm 16mm 17mm 19mm 20mm 25mm Keyway Width (w) 10mm 3mm 3mm 1. js9 widthChart keyway sizing engineering Keyway broach tool m4 keywaysMetric keyway sizes. Keyway Connection. tolerances according to ISO 7H (shaft spline) and 7n (internal spline) are recommended. W = d/4[clarification needed] H = 2d/3[clarification needed] where. Minimum Hardness. About Keyway Broach Tools. Bore Size Chart. 095 . Key Dimensions The inch and metric dimensions here correspond to common values. For Hub Keyway Height. H9/e9. Metric module, side fit. 002-0. Depending on the slot width tolerance, the following fit or seating results in combination with the parallel key: Tolerance b Hub keyway b Shaft keyway for tight fit P9 P9Type L-Jaw Coupling Rating Chart; Type L-Jaw Cross Reference Chart; Displays. Key & Keyway Dimensions Millimeters Shaft Diameter. 2 (1978) and ANSI B4. Keyseats and Keyways. The invention belongs to the technical field of measurement of the keyway symmetry degree, and particularly relates to a method for measuring the keyway symmetry degree of a shaft part. 18. Keys and keyways. Bore Tolerances Keyway & Setscrew Sizes. Pivots, latches, fits of parts exposed to corrosive effects, contamination with dust and thermal or mechanical deformations H9/C9, H9/d10,H9/d9, H8/d9, H8/d8,D10/h9, D9/h9, D9/h8 Running fits with greater clearances without any special requirements for accuracy of guiding shafts. This Standard covers the size, type and tolerances of parallel and taper keys and keyseats, and their relationship to shaft diameters and bore diameters. Cross-section of a parallel keyed joint. 5. XXX 0. Shaft Diameter. 0. 0015 0. H7/h6. We use keyed shafts in the gear and shaft assemblies in general. Here we can calculate rigid connections, namely the pinned, keyed, splined and flanged ones. Keyways Index BS 46 Keys and keyway Dimensions-Parallel Rectangular Ref Standard . 000/+. ISO 286 1 2010 Geometrical. ISO Tolerance Zone According To According To According To According To According To According To; h9 h9 h11 min max DIN 6881 DIN 6883 DIN 6884 DIN 6885 DIN 6886 DIN 6887 DIN 6889 (8 x 7)We also have an Metric Keyway Calculator. 314 1. 437 / . Keyway designation Key bow Chain hole Key cuts Keyway milling Serialization code Key blade Key stop tip Series keymark. 002" and causing problems assembling. The advantage of the Js9 tolerance is that the key can be inserted and the gear manipulated without much difficulty. center of the keyway. 3750. This publication is intended to provide dimensions and tolerances, which permit bushings made by one manufacturer to be used to mount sheaves or other products made by. Pivots, latches, fits of parts exposed to corrosive effects, contamination with dust and thermal or mechanical deformations H9/C9, H9/d10,H9/d9, H8/d9, H8/d8,D10/h9, D9/h9, D9/h8 Running fits with greater clearances without any special requirements for accuracy of guiding shafts. With tight tolerances and top-quality materials, our keys and cores set the standard for security and functionality. Metric key keyway dimensions per iso/r773. industry accepted ANSI/AGMA 9002-B04 Standards’ tolerance for common keyways and clearance fit bores unless otherwise specified. 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. 342 Minimum 3. a bolt) or when something else like a keyway will secure it. 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 - Ch) 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 body The second is a P9 tolerance. 2 Tolerance of a basic size for specific tolerance grade. clearance fit bores with set screws. 3. Generally, there are two classes of stock available for sunk keys, mainly parallel keys.