IT Grade
Overview
In Werk24, IT Grades (International Tolerance Grades) are used to describe the manufacturing precision of a mechanical component. These grades define the acceptable deviation from a nominal dimension, ensuring consistency and interoperability in machining and engineering processes.
As a software developer integrating Werk24 into your workflow, it is essential to understand how IT Grades impact design, manufacturing, and quality control so you can correctly process and interpret extracted data.
What Are IT Grades?
IT Grades are standardized tolerance levels that indicate how precisely a part must be manufactured. They are defined by ISO 286-1 and ISO 286-2, with the tolerances becoming tighter (more precise) for lower IT numbers and looser (less precise) for higher IT numbers.
- The lower the IT number, the higher the precision (e.g., IT1 is ultra-precise, used in optical instruments).
- The higher the IT number, the looser the tolerance (e.g., IT16 is used for rough, non-critical parts).
- IT Grades apply to both shafts and holes, defining the allowable deviation from the nominal dimension.
IT Grade Table
Below is a simplified reference of IT Grades and their typical applications:
| IT Grade | Description | Typical Application |
|---|---|---|
| IT1 - IT3 | Ultra-high precision | Optical instruments, measurement devices |
| IT4 - IT6 | High precision | Bearings, precision tools, fine machining |
| IT7 - IT9 | General machining tolerances | Standard engineering components, gears |
| IT10 - IT12 | Coarse machining | Bolts, nuts, general manufacturing |
| IT13 - IT16 | Very coarse tolerances | Castings, welded structures, rough parts |