Knowledge · Problems and wear

Blade not cutting? Core bit jamming?The cause is almost always the selection.

The most common problems with diamond tools have four causes: a bond not matched to the material (glazing or too fast wear), overheating without cooling (lost segments), wrong operating parameters (feed pressure, speed) and a damaged core (run-out, vibration). The look of a worn segment reveals the cause.

Updated: Prepared by: OnlyTools technology departmentReviewed by: Zbyszek Zięba5 answers · 5 articles coming soon

The key points in 30 seconds

  • Smooth, shiny segment = glazing → the bond is too hard for the material.
  • Segment worn very fast = the bond is too soft for an abrasive material.
  • Broken segments = impact on rebar, overheating or dry cutting. Diagnosis by segment appearance.
  • Oval wire beads = the wire is not rotating – twist it by about 1–2 turns per metre.

Why does a diamond blade stop cutting?

Usually it is glazing: the bond is too hard for the material, the diamonds go blunt and do not expose new ones. Cutting an abrasive material helps in the short term; a blade with a softer bond is the lasting fix. How to recognise bond hardness on a blade datasheet: guide to segment specification. The most common case in concrete: granite or basalt aggregate.

Why does a blade run out of true and vibrate?

A bent or overheated core, the wrong rotational speed, worn machine bearings or a dirty flange. Run-out must be measured before further work.

Why does a core bit jam?

Debris not flushed out, too little side clearance on the segments, a tilted core drill or the element shifting during drilling.

How do you tell normal wear from faulty wear?

Normally the segments wear evenly over their height, with the grit visible. Uneven wear, a shiny surface, cracks or breakouts point to a selection or parameter error.

Articles in “Problems and wear”

  • Coming soon

    Why a diamond blade stops cutting (glazing)

    How to recognise it and how to dress the segments.

  • Coming soon

    Lost segments – 5 causes and how to prevent them

    Overheating, undercutting, impact, joint.

  • Coming soon

    Blade run-out – diagnosis before retipping

    When a core is fit for further work.

  • Coming soon

    Core bit jamming in reinforced concrete

    Water, side clearance and drilling square.

  • Coming soon

    Segment wear atlas – photos and causes

    Diagnosis by segment appearance.

Online tools and related pages

Prepared by

OnlyTools technology department

This content is written by technologists who formulate bonds and press segments in our plant in Zagórze Śląskie, Poland. The figures are indicative – a technical advisor confirms the right selection.

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