Indexable insert grade for turning ISO-P steels

Tool change before tool breakage: indexable insert "predicts" its demise

Due to the vast range, machining ISO-P steels is anything but simple. To make machining the biggest material group in metal machining easier for machine operators, we have rethought everything from the substrate to the geometries, right through to the coating – for optimal breakage resistance and hardness of cutting edges. The Dragonskin coating makes a decisive contribution here. Its optimised structure is designed specifically to increase tool life and reduce machining time. Mechanical post-treatment enables us to achieve the layer surface's unique state of residual stress, which pays off in terms of increased process security, especially in large-scale production. In comparison with our predecessors, the indexable inserts for grades CTCP135-P, CTCP125-P and CTCP115-P achieve up to twenty-percent-longer service lives.

Once it reaches the end of its life cycle, every cutting insert experiences a drop in performance. If pushed to its limit, it can even break – and endanger the entire process. However, if the user identifies the wear using the new indexable insert indicator layer, they can replace it in a timely manner. At the request of our customers, we have incorporated this feature into the latest generation of the steel turning grade in the form of the special Dragonskin coating – for stable and conflict-free processes!

All the advantages of the turning grade at a glance:
  • Three grades for machining ISO-P steels
  • Indicator layer makes tool wear visible
  • Up to twenty-percent-longer service lives in comparison with predecessors
  • Special Dragonskin coating with optimised structure increases tool life and reduces machining time
  • CTCP115-P (ISO P15) specially for smooth cuts with stable cutting conditions and continuous cuts
  • CTCP125-P (ISO P25) for turning operations from finishing to rough machining
  • CTCP135-P (ISO P35) for interrupted cuts in unstable and difficult conditions

Thanks to the CVD multilayer coating with the Dragonskin coating technology, the indexable inserts are ideally suited to versatile steel machining. In combination with a balanced carbide base substrate, the new grades in the ISO-P category boast a wide application area with improved wear resistance.

Depending on the cutting conditions, the perfect cutting material can be selected from three grades:


  • ISO-P15
  • Wear-resistant grade with high degree of elevated-temperature resistance for steel machining with optimum tool life
  • High cutting speeds
  • Maximum productivity
  • For a smooth cut


  • ISO-P25
  • Universal carbide grade for steel machining
  • Excellent balance between toughness and elevated-temperature resistance
  • High level of reliability for machining general steel
  • Excellent for fluctuating cutting conditions, from finishing to roughing


  • ISO-P35
  • Tough carbide grade for interrupted cuts
  • Guaranteed process security for low cutting speeds and unstable conditions

Test report for the old and new indexable insert

Indexable insert: CNMG 120408EN-M50
Material: 1.2343 – X37CrMoV 5-1 44 HRC
Cutting data: vc 70-130 m/min | f 0.35 mm/U | ap 2 mm

Performance increase of the new grades:

Cutting speed vc Increase in %
70 m/min 20
100 m/min 44
130 m/min 45

Result: Depending on the cutting speed, an increase in performance of up to 45% can be achieved with the CTCP115-P grade.

Wear detection comparison between CTCP115 & CTCP115-P

Wear detection means that optimum utilisation of the multi-edged indexable insert can be identified with a quick glance at the cutting edges. Wear on the cutting edges is also easier to see and easier for the machine operator to identify.

→ 10 cuts

→ 1 cut

In episode 7 of THE CUT, host Brian Lorenzen, Product Manager Stefan Karl and Innovation Managerin Kathtrin Weirather are talking about the challenges of turning steel, the latest developments in turning and our new ISO-P grades with indication layer - the perfect fit for turning steel. 

Buy negative insert grade CTCP115-P | CTCP125-P | CTCP135-P now

Buy positive insert grade CTCP115-P | CTCP125-P | CTCP135-P now