DIMENSIONAL ENGINEERING
Limits & fits
From basic dimensions to a precise fit.
Define the components
Starting points, not application recommendations. Fit type is calculated from the limits.
Bore D
Shaft d
ISO 286 metric tables. Inch dimensions use exactly 25.4 mm per inch.
Calculation results
Clearance fit
Tolerance zones
Common diameter axis; each dashed line marks that component’s basic dimension. Zone widths are to scale.
Dimensions & deviations
Three metric decimals normally; extra digits retain fractional-micron values. Inch values marked ≈ are rounded. Classification uses unrounded values.
Keep this calculation
Saved on this device. Export a backup to move between devices.
Saved calculations
How to read the results
Upper and lower deviations are offsets from each component’s basic dimension. Add the deviations to that basic dimension to obtain maximum and minimum permissible sizes.
Minimum clearance = minimum bore − maximum shaft. Maximum clearance = maximum bore − minimum shaft. Negative clearance means interference. All-positive or zero-to-positive clearance is a clearance fit; all-negative or negative-to-zero clearance is an interference fit. A range crossing zero is a transition fit.
Unequal basic dimensions are evaluated independently, using each component’s own ISO size range. The resulting classification is a size-limit comparison, rather than a conventional shared-size ISO fit designation.
These are dimensional results at the reference temperature of 20 °C. The optional Assembly Method section evaluates a simplified elastic and thermal model for standard cylindrical parts. Bearing scenarios provide guidance only.
Supported data, offline use & privacy
407 tabulated classes; nominal dimensions greater than 0 to 3150 mm where a table entry exists. Some positions and grades have narrower ranges. Unavailable entries are rejected. IT01, IT0 and unlisted class/range combinations are not implemented.
ISO 286-2:2010 numeric limits with the 2013 corrections. The inconsistent za11 entry above 225 to 250 mm is deliberately unavailable. Read calculation assumptions, references and verification notes.
Checking offline availability…
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Specify the known component
Choose the required fit
The opposing component uses the same basic diameter unless you change the advanced settings.
Advanced search & filters
Maximum 101 diameters. Searches start + n × increment, up to the end; an off-grid endpoint is not added.
Optional target limits
The entire signed clearance interval must fall inside these bounds. Negative clearance means interference. Leave blank for no restriction.
Results update as you change inputs. Each candidate uses the existing ISO calculation engine.
Matching combinations
Selection aid based on dimensional limits only. Common status does not establish suitability for a load, material or application.
Compare selected fits
One common diameter axis. Dashed lines mark basic dimensions. Extra metric digits are retained where needed.
How Fit Finder selects and ranks results
Every proposed class and diameter is passed through the same ISO engine as the main calculator. Unsupported entries and non-positive permissible sizes are excluded. Classification uses the unrounded signed clearance interval; letter designations do not determine the result.
Strictly positive minimum clearance means guaranteed positive clearance. A negative maximum clearance means guaranteed interference. A range spanning zero is transition. If exactly one endpoint is zero, the result is labelled clearance or interference with “zero at limit”; it is not labelled guaranteed positive clearance or guaranteed interference.
The “Common combination” badge identifies an explicitly listed pair from a curated subset of MISUMI’s hole- and shaft-basis fit selection tables, and only when the basic dimensions match. Other supported pairs are labelled “Valid custom combination”. This is a recognition list, not an exhaustive list of useful fits or a suitability assessment.
Default ranking places this common set first in a documented display order. Other candidates are ordered by distance from IT6 for shafts or IT7 for bores, then designation and basic diameter. These are browsing preferences, not mechanical recommendations. Numeric sorting applies within common/custom groups while common priority is enabled; disable it for a single numerical sort.
Target limits constrain the complete calculated interval. For positive interference magnitudes: minimum interference = −maximum clearance; maximum interference = −minimum clearance. Setting an interference target excludes candidates with possible positive clearance. Unlocked ranges include only the explicitly requested start/increment grid; no intermediate or off-grid sizes are proposed.
Use This Fit opens the original calculator, where you can change, save, export or print it. Returning here preserves the search criteria and comparison until you close or reload the page. Existing favourites and backup formats are unchanged.