grinding wheel type
The type of the wheel is marked as an ISO number and signifies the wheel’s shape. For example, ISO Type 52 is a spindle-mounted wheel.
The size of the grinding wheel is marked as dimensions in mm. For example, 100x6x16mm. This
represents the wheel’s diameter x thickness x hole size
The specification of the grinding wheel is marked as a series of letters and numbers. For example, WA 60 K 7 V. This represents the type of abrasive material, the grit size, the grade, the structure, and the bond type. A general guide to specification marking can be seen in the table here:
The range of material markings, grit sizes, grades, structures and bonds depends on the product and the manufacturer, but the table above gives a general outline of common markings seen on abrasive wheels.
The maximum operating speed grinding wheel
is marked on every large grinding wheel (above 80mm in diameter) in two ways:
- The peripheral surface speed, given in metres per second. For example, 80m/s.
- The rotational speed, given in revolutions per minute. For example, 8500rpm.
For smaller grinding wheels (below 80mm in diameter), the maximum operating speed is provided on a separate notice which must be stored alongside the wheel.
For high speeds, colour-coded stripes are also marked across the centre of the wheel. The colours are:
- 50m/s – Blue
- 60m/s – Yellow
- 80m/s – Red
- 100m/s – Green
- 125m/s – Blue/Yellow
The restrictions for use are marked on the grinding wheel using a code and, in some cases, a corresponding graphic. The markings used to show restrictions are as follows:
- The manufacturer’s trademark/name.
- The test record number, indicates it meets the standards for safety.
- The expiry date if it’s an organic bonded wheel (this will be 3 years from the date of manufacture).
- A traceable code number, indicates the source and manufacturing details of the wheel.
- A mounting arrow, indicating the heaviest point of the wheel. The arrow should point downwards when the wheel is mounted.