Interference Fit Chart

The first principle to grasp is the fit designation of the shaft hole joint.

Interference fit chart. The purpose of the interference fit with a keyed shaft is to axially locate the. 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. Depending on the amount of interference parts may be joined using a tap from a hammer or pressed together using a hydraulic ram. Locational interference fits are used where accuracy of location is of prime importance and for parts requiring rigidity and alignment with no special requirements for bore pressure.

Units given in inches. Fit is defined as the degree of freedom of tightness between the mating parts in an assembly process it is also defined as the relationship between the hole and the shaft during the assembly is called fit in this article we are going to discuss different types of fits in a detailed way. Class i loose fit use for all possible hole shaft applications where function will permit. Select class xx based on required functional fit to access page.

An interference fit also known as a press fit or friction fit is a form of fastening between two tight fitting mating parts that produces a joint which is held together by friction after the parts are pushed together. The various parameters that can be included are maximum interference minimum interference maximum. H9 e9 h8 e8 h7 e7 e9 h9 e8 h8 e8 h7 running fits with greater clearances without any special requirements for fit accuracy main fits of machine tools. H7 n6 h8 n7 h8 p7 h7 m6 h8 m7 m8 h6 n7 h6 n8 h7 location interference.

Some of the selected preferred fits. The size ranges given are for typical size ranges utilized within industry. The interference fit standard for most couplings made of medium carbon steel are 0 00050 0 00075 in in mm mm interference up to 1800 rpm and 0 00075 0 00100 in in mm mm over 1800 rpm. Locational interference fit for parts requiring rigidity and alignment with prime accuracy of location but without special bore pressure requirements.

Medium drive fit for ordinary steel parts or shrink fits on light sections the tightest fit usable with cast iron. Mechanical tolerance standards charts. Clearance to interference fits. Critical components that must not sustain.

For more industry standard tolerance data see. Table ii reflects interference fits used for nema frame size motor shafts. This type of fit where the assembled parts requiring rigidity and great alignment with prime accuracy of location. Graphical representation of ansi b4 1 1967 locational interference fits table locational interference limits and fits for cylindirical parts ansi b4 1 1967 r1987 all limits shown in chart below are in thousandths of an inches.

Multiple fits of shafts of production and piston machines parts rotating very rarely or only swinging. Class v locational interferance fit tolerance chart for holes and bolts per mcdonald douglas design guide machining tolerances.