ISO 286 Tolerance Bands (IT Grades 1–14) – 1 to 315 mm

This table gives the ISO tolerance band width T for IT Grades 1 to 14 over nominal sizes from 1 mm to 315 mm. The values are given in micrometres (µm), where 1 µm = 0.001 mm.

The IT grade determines the width of the permitted tolerance zone. A lower IT grade number represents a smaller tolerance band and therefore greater dimensional accuracy. The value T is the total width of the tolerance zone; its position relative to the basic size is determined separately by the fundamental deviation for the selected hole or shaft designation.

How to Read the Tolerance Band Table

For example, for a nominal diameter of 40 mm and IT Grade 7, use the size range over 30 mm up to and including 50 mm. The table gives a tolerance band width of 25 µm, equivalent to 0.025 mm.

This value defines the width of the tolerance zone only. The appropriate hole or shaft fundamental deviation must also be obtained to determine the actual upper and lower dimensional limits.

Need help using this table? See How to Use ISO 286 Tolerance and Fit Tables for worked examples showing how IT grades are combined with fundamental deviations to calculate hole and shaft limits.

Related ISO Tolerance Tables

• ISO Shaft limit nearest Zero
  (3-500mm shaft size)
• ISO Hole Nearest limit nearest Zero
  (0-500mm hole size)
• ISO Tolerance Band T
  (315-3150mm size)
• ISO Shaft limit nearest Zero
  (500-3150mm shaft size)
• ISO Hole Nearest limit nearest Zero
  (500-3150mm hole size)
• ISO Hole Limits (3-400mm Hole Size)
• ISO Shaft Tolerance(3-400mm Hole Size)
• ISO Hole Limits (400-3150mm Hole Size)
• ISO Shaft Tolerance(400-3150 mm Hole Size)