» Pulp, chemical » Wood processing » Knife systems
Changing TurnKnife in a chipper with Dragos
3 TurnKnives from rightChips in hand

Knife systems

The heart of the chipper

The challenge

It is a continual challenge to improve the efficiency and productivity of wood processing operations. One specific challenge is to produce the highest volume of uniform wood chips – increasing accepts and reducing fiber losses – in a safe working environment.

The solution

ANDRITZ Iggesund Tools offers a range of chipping knife systems that help achieve high and uniform production with minimal losses. This range of knife systems ensures a solution that meets the specific requirements and layout of each plant’s chip processing operation.

TurnKnife systems

ANDRITZ Iggesund Tools TurnKnife systems increase the performance and efficiency of all types of chippers and sawmill chipping equipment. The TurnKnife system produces more high quality and uniform chips, with a higher accept fraction.

Produced from the highest quality alloy chromium steel, the knives are specially treated to have a much longer edge life than conventional knives. The TurnKnife has a double-edge, making it reversible to eliminate knife grinding. The patented design ensures precise and consistent knife location to maximize chipping performance.



The longer time between knife changes helps increase the chipping capacity. During operation, the TurnKnife stays sharper longer, which provides a better cut and minimizes small chip fractions (pin chip and fines). These factors ensure better downstream processes while saving money in the wood processing operation.

TurnKnife TK-IV cassette in a chipper disc

TurnKnife TK-IV cassette in a chipper disc

Upgrading a chipper to the TurnKnife system improves chip quality and chipper performance with excellent economics.

TurnKnife features

  • Easy and fast knife changes
  • One man knife changes from the front of the chipper
  • Precise and consistent knife location
  • Longer time between knife changes − fewer chipper shutdowns
  • Higher and more uniform chip quality
  • Improved safety and efficiency with light knives and no knife grinding

TurnKnife TK-IV cassette with knife protracted

TurnKnife TK-IV cassette with knife protracted

ANDRITZ Iggesund Tools offer TurnKnife systems for different applications: large disc chippers, drum chippers, rechippers after chip screens, or different sawmill chipping heads.  All of these can be upgraded to the TurnKnife system.

TurnKnife systems

  • TurnKnife System II (TK-II)
  • TurnKnife System III (TK-III)
  • Super TurnKnife – Next Generation (STK-NG)
  • TurnKnife System IV (TK-IV)

TurnKnife TK-IV is the latest knife system for all kinds of roundwood chipping. It combines a lightweight design with the power and strength to cope with all sorts of wood species. TK-IV has an excellent chipping geometry and extremely long running time between knife changes.

TurnKnife TK-IV knife

TurnKnife TK-IV knife

PartnerChip full service contract

Close customer collaboration is a top priority for ANDRITZ. PartnerChip is a service program for knife systems. We provide the TurnKnife system plus the expertise of our specialists on a fixed-fee basis with the goal of helping you maintain the most efficient and profitable chip production possible.  By including scheduled preventive maintenance, on-call 24-hour service, and technical support, you are assured safe and efficient production of your chipper.

Benefits of the PartnerChip contract

  • Reliable TurnKnife system
  • Scheduled service and on-call 24-hour service
  • No inventory costs − no tied-up capital
  • Technical support and chip quality optimization

Supporting systems

HQ-Plus Quick Clamp system

The HQ-Plus Quick Clamp is a hydraulic clamping system for TurnKnife. The combination of Quick Clamp and TurnKnife allows very fast knife changes and long running time between knife changes.

Dragos knife-changing robot

Dragos is an intelligent knife-changing robotic device that loosens and tightens all the bolts in the TurnKnife cassette in the correct order.  Bolts are tightened to exactly the right torque. Dragos has a joystick so that the operator can easily position the disc to the correct position for knife changing.

Dragos for ANDRITZ HHQ chipper

Dragos for ANDRITZ HHQ chipper


The ScanChip analyzer uses image analysis technology to monitor chip quality in a fast and accurate way. Different chip size distribution methods can be simulated and it also measures the chip dimensions (length, width, and thickness). ScanChip provides the information required to adjust a TurnKnife system in the chipper to produce optimal chip quality.

ScanChip with operator

ScanChip analyzer with operator


ANDRITZ Iggesund Tools AB, Sweden
Phone +46 (650) 291 00

Contact us


ANDRITZ Iggesund Tools Inc., USA

Phone +1 (813) 855 6902

Contact us


ANDRITZ Iggesund Tools Canada Inc., Canada
Phone +1 (450) 973 4343

Contact us

Related links



Sawmill products

Wood processing services

Wood processing technology

Kraft mill services



Helical Face Technology for chipping (HFT)

Upgrade to the TurnKnife system in the chipper

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