Tolerance Fit Calculator

"Tolerance Fit Calculator" is a professional tool app designed for mechanical engineers, machining technicians, and mechanical engineering students. Based on the ISO 286 standard, simply enter the nominal diameter and calculate limit deviations, fit type, maximum clearance/interference with one tap. Provides smart fit recommendations, 3D visualization, thread calculations, material weight calculation, and other practical features. Fully offline, no internet required, carry it with you anytime, anywhere. Core Features Tolerance Fit Calculation Supports nominal diameters from 0 to 3150 mm, all tolerance zones for holes A～ZC, all tolerance zones for shafts a～zc, all tolerance grades IT1～IT18 Automatically identifies clearance fit, transition fit, and interference fit Smart fit recommendation engine: automatically recommends the optimal tolerance combination based on fit requirements 3D Visualization 2D tolerance zone diagram: intuitively shows the relative positions of hole and shaft deviation ranges 3D model assembly: dynamically demonstrates the looseness/tightness under maximum clearance/maximum interference conditions, supports gesture rotation and zoom Practical Tool Set (7 Tools) Thread & fastener calculation: thread tapping hole diameter, bolt tightening torque Material weight calculation: 10+ materials (steel, aluminum, copper, etc.), 5 shapes (round bar, square bar, plate, etc.) Cutting parameter calculation: spindle speed (RPM), feed rate, cutting speed, supports turning/milling/drilling Tolerance dictionary & GD&T knowledge base History and favorites Target Users Mechanical design engineers: quickly verify the rationality of tolerance fits in designs Machining/CNC operators: look up tolerances and cutting parameters on-site Quality inspection and process personnel: quickly obtain limit deviation values during inspection and acceptance Mechanical engineering students: learn tolerance fit knowledge, deep dive with GD&T knowledge base Tolerance Fit Calculator is an offline tool developed for mechanical design, machining, and inspection personnel. Based on the ISO 286 standard, simply enter the nominal diameter, select the tolerance zones and tolerance grades for the hole and shaft, and quickly obtain: Limit deviations of hole and shaft (upper deviation / lower deviation) Fit type (clearance fit / transition fit / interference fit) Maximum clearance and minimum clearance (clearance shown as "+", interference shown as "－") Input Range & Limits Diameter range: 0.001 mm ~ 3150 mm Input digit limit: up to 6 significant digits Supported Tolerance Zones Type Tolerance Symbols Hole tolerances A, B, C, CD, D, E, EF, F, FG, G, H, JS, J, K, M, N, P, R, S, T, U, V, X, Y, Z, ZA, ZB, ZC Shaft tolerances a, b, c, cd, d, e, ef, f, fg, g, h, js, j, k, m, n, p, r, s, t, u, v, x, y, z, za, zb, zc Supported Tolerance Grades All grades IT1 ~ IT18 Special Rules Description (Strictly following ISO 286) The app has built-in the following standard special rules to ensure accurate and compliant calculations: Holes A and B are not applicable to nominal sizes of 1 mm or less Shafts a and b are not applicable to nominal sizes of 1 mm or less JS 7～JS 11: truncate the decimal part of IT/2 to make it an integer in micrometers (round down) js 7～js 11: similarly round IT/2 down to an integer in micrometers Hole J is only supported for grades IT6～IT8 Shaft j is only supported for grades IT5～IT8 Tolerance grades IT14～IT18 are not applicable to nominal sizes of 1 mm or less For nominal sizes larger than 500 mm, the tolerance values for IT1～IT5 are temporary experimental values (the app will give a prompt) Core Workflow Enter the nominal diameter (up to 6 digits) Tap the tolerance zone buttons to select the hole tolerance (e.g., H) and shaft tolerance (e.g., h) Download now to make tolerance calculation more efficient and reliable!