One of the most common questions when replacing a cutting disc on a grinder (grinder): which side should I put the disc on - with the metal ring facing the clamping nut or the support flange? A mistake here affects not only the quality of the cut, but also safety.
Short answer from NovoAbrasive: the metal cutting disc (type 41) is installed with the metal ring facing outwards - from the side of the clamping nut. The smooth abrasive side is adjacent to the wide support flange.
In the new guide, we have examined in detail:
- why is a metal ring needed and what four functions does it perform;
- why is the disc placed with the ring facing the nut and what will happen if you do it the other way around;
- step-by-step instructions for installing the disk and starting it up;
- What is more important - the side of the ring or the direction of rotation arrow?
👉 Read the full guide: Which side to install the cutting disc on a grinder
Frequently asked questions
Which way round should a cutting disc go on an angle grinder?
A type 41 metal cutting disc is fitted with the metal ring facing outwards — towards the clamping nut. The flat abrasive side then sits against the wide backing flange.
What is the metal ring on a cutting disc for?
The ring reinforces the bore, spreads the clamping load, stops the nut pressing into the abrasive and carries the marking — which is why it must stay on the nut side.
Should you run the grinder without load after changing a disc?
Yes. After fitting, run the tool briefly with no load and check there is no wobble, vibration or unusual noise.
