
The component that supports the compressor and connects it to the engine is our focus we’ll call it the “compressor base”. Figure 1 shows a vehicle engine with a compressor for AC. In order to understand the content of this standard and its parts, it’s best to use a real engineering example. Such instances are normal, and not uncommon, so you should always check the drawing title block for general tolerance requirements and note any special part specifications or project requirements.
ISO 2768 MK TOLERANCE CHART PDF ISO
The standard is made of general rules because there are exceptions when a dimension on a part needs a tighter tolerance than those set by ISO 2768. By including the ISO 2768 specification, you are simplifying your drawing, and avoiding writing tolerances for every dimension and feature.

The bars also vary in length and when you take a closer look, you realize they are not perfectly circular.Ĭan you still use them? If not, can you reject them and demand that the vendor redo them at no cost? How close to the Ø50mm should you really be? ISO 2768: An International Standard You place an order to fabricate 200 of these Ø50mm rounds bars and when you receive and measure them, you get values like Ø53mm, Ø47mm, Ø51mm, Ø49mm, with a lot of variation. In other words, it’s a controlled margin of error.įor example, let’s say you specify a round solid bar of 100mm length with Ø50mm that will fit inside of a hole in another component. These tolerances represent the variations between nominal dimensions (the original intention of the design) and the maximum and minimum values of a dimension that still guarantees a fit.

In manufacturing, this range of acceptance is defined by tolerance limits. That said, you can decide how much a fabricated product can deviate from the original intention in order to be accepted. Even if you’re able to get an instance comparable to your design intention, it’s nearly impossible to achieve the same exact dimensions in a batch process. Fabricating a product without deviations from the original design is extremely complicated.
