![]() a tolerance, this being the variation in size acceptable in manufacture while ensuring the functional fit requirements of the product. In order that the fit function could be satisfied, it was found sufficient to manufacture a given workpiece so that its size lay within two permissible limits, i.e. The need for limits and fits for machined workpieces was brought about mainly by the requirement for interchangeability between mass-produced parts and the inherent inaccuracy of manufacturing methods coupled with the fact that”exactness “of size was found to be unnecessary for most workpiece features. This part of ISO 286 is a geometrical product specification(GPS)standard and is to be regarded as a general GPS standard (see ISO/TR 14638 ).It influences chain links 1 and 2 of the chain of standards on size in the general GPS matrix.įor more detailed information on the relationship of this part of ISO 286 to the GPS matrix model, see Annex B. Permanent couplings of gears with shafts, flanges.ISO 286-2:2010 pdf free download.Geometrical product specifications (GPS) - ISO code system for tolerances on linear sizes - Part 2: Tables of standard tolerance classes and limit deviations for holes and shafts. Assembly using pressing and great forces under different temperatures of the parts. Permanent coupling of gears with shafts, bearing bushings. Assembly using cold pressing only with use of large forces. Assembly of the parts can be carried out using cold pressing. Pressed fits with guaranteed interference. ![]() Mounting of fits using pressing and light force.įixed plugs, driven bushings, armatures of electric motors on shafts, gear rims, flushed bolts. H8/p7, H8/m7, H8/n7, H7/m6, H7/n6, M8/h6, N8/h7, N7/h6įixed fits with negligible clearances or small interferences. The parts can be assembled or disassembled without great force using a rubber mallet.ĭemountable fits of hubs of gears and pulleys, manual wheels, clutches, brake disks. Similar fits with small clearances or small interferences. The parts can be assembled or disassembled manually.Įasily dismountable fits of hubs of gears, pulleys and bushings, retaining rings, frequently removed bearing bushings. ![]() Tight fits with small clearances or negligible interference. Precise guiding of machines and preparations, exchangeable wheels, roller guides. Mounting by sliding on without use of any great force, after lubrication the parts can be turned and slid by hand. Sliding fits with very small clearances for precise guiding and centring of parts. The parts can easily be slid one into the other and turn.Įasily demountable parts, distance rings, parts of machines fixed to shafts using pins, bolts, rivets or welds. Slipping fits of parts with great tolerances. Parts of machine tools, sliding gears and clutch disks, crankshaft journals, pistons of hydraulic machines, rods sliding in bearings, grinding machine spindles. Without any noticeable clearance after assembly. Running fits with very small clearances for accurate guiding of shafts. General fits of shafts, regulator bearings, machine tool spindles, sliding rods. Running fits with smaller clearances with general requirements for fit accuracy. in agricultural machines, bearings of pumps, fans and piston machines. Running fits with greater clearances without any special requirements for fit accuracy.įits of long shafts, e.g. Multiple fits of shafts of production and piston machines, parts rotating very rarely or only swinging. Running fits with greater clearances without any special requirements for accuracy of guiding shafts. Pivots, latches, fits of parts exposed to corrosive effects, contamination with dust and thermal or mechanical deformations. Calculate upper and lower limits for shafts and holes (bores).
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