Indexable insert grade for turning ISO-P steels

Inserts with wear detection means you can recognize insert wear before it fails

Due to the variety of material types classified in the ISO-P range, choosing the right insert to machine this material can be challenging. To make machining one of the most common material groups in the industry easier to navigate, we have rethought everything about the insert; the substrate, geometries, and coatings. Because of its optimized coating structure that increases the tool life, The Dragonskin coating is critical to the success of our inserts. 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 legacy grades, the new CTCP135-P, CTCP125-P, and CTCP115-P achieve up to twenty percent longer tool life.

Learn how Dragonskin coating is part of 100 years of Cutting Tool Progress.

As inserts wear and approach the end of their tool life, there can be a drop in performance. If pushed too far, there can be a catastrophic failure, which could negatively impact other parts of the machining 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 reliable processes.

At-a-glance: Advantages of the steel turning grade
  • Three grades for machining ISO-P steels
  • Indicator layer makes tool wear visible
  • Up to twenty-percent-longer tool lives in comparison with previous grade generations
  • Special Dragonskin coating with optimized structure increases tool life and reduces machining time
  • CTCP115-P (ISO P15) is ideal for finishing and also for use in smooth, continuous cuts in stable cutting conditions
  • CTCP125-P (ISO P25)  offers a wider application range for turning operations from finishing to rough machining
  • CTCP135-P (ISO P35) is for interrupted cuts in unstable and difficult conditions

Due to the CVD multilayer coating with 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

The wear detection capability means wear on the cutting edges is easier to see and easier for the machine operator to identify. That way, operators are fully aware when a tool change is needed and the multi-edged indexable insert is fully utilized. 

→ 10 cuts

→ 1 cut

In Folge 7 von THE CUT sprechen Gastgeber Brian Lorenzen, Produktmanager Stefan Karl und Innovationsmanagerin Kathtrin Weirather über die Herausforderungen beim Drehen von Stahl, die neuesten Entwicklungen beim Drehen und unsere neuen ISO-P-Sorten mit Indikationsschicht - die perfekte Lösung für das Drehen von Stahl. 

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

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