Upcoming events
The K Show at Stand A03 in Hall 10- Dusseldorf, Germany — October 08 - 15, 2025
[ 01 ]
Cost saving

Refurbishing can generate 30% or more costsaving aginst new parts.

[ 02 ]
Shorter delivery time

Repair is mostly faster than new so in critical situations reduce downtime of the machine if something is broken and not available on stock

[ 03 ]
Choice of different welding materials

Material weld can be adjusted to current needs.

Cylinder Repair through larger a larger inner diameter

A worn cylinder, bimetallic or nitrided, can be repaired by honing the inner diameter to a larger diameter. In case of nitrided cilinders a new nitriding treatment shall be made with a depth of 0,4 ÷ 0,5 mm to ensure the necessary hardness. A honing operation must follow so that all dimensions are within the new oversized tolerances. In case of a bimetallic cylinder only the boring needs to be honed. No renitriding and honing is necessary. Of course the outer diameter of the screw, valve and eventually end cap inner diameter must be adjusted to the new (larger) dimension of the cylinder. This is a cheap but effective solution but has one disadvantage: the repaired cylinder and screw become non standard equipment and dedicate spare components shall be stored.

Repair with bushing

In special cases Injection cylinders can be repaired by reline the worn area with a liner which shall be longer as the screw stroke (5D) so the valve operate at the original nominal diameter. The liner can be made of nitrided steel, hardened steel but also of bimetallic alloy.

Repair old worn screws by welding the flights

For screws with diameters larger than 60 mm, depending on the type of wear, it is possible to repair them by welding new material on the top of worn flights. This procedure can be applied only if there is no wear on the screw core or front-back flight radius, Important to mention is that a repaired screw will not last as long a new one. For further information about the welding alloys, please refer to the table below.

Welding materials for the screw flights

For larger screw sizes we often use nitrided materials with the flighttips welded welded with different materials options. This creates wear/corrosion protection or improves friction/lubrication.

  • MM CODE
    FLIGHT ARMORING
    TECHNOLOGY
    ABRASIVE WEAR RESISTANCE
    CORROSIVE WEAR RESISTANCE
  • MM120
    Cobalt Base Alloy
    PTA
    +++
    +++
  • MM50
    Iron Base Alloy
    TIG
    ++++
    ++
  • MM560
    Nickel Base Alloy
    PTA
    ++++
    ++++
  • MM570
    Nickel Base Alloy
    PTA
    ++++++
    +++++
  • MM830
    Nickel Base Alloy
    PTA
    +++++
    +++++
  • MM4900
    Molybdenum
    HVOF
    +++++
    ++++
  • MM6000
    Tungsten Carbide
    HVOF
    ++++++
    ++++++
MM120
  • MM CODE
    MM120
  • FLIGHT ARMORING
    Cobalt Base Alloy
  • TECHNOLOGY
    PTA
  • ABRASIVE WEAR RESISTANCE
    +
    +
    +
  • CORROSIVE WEAR RESISTANCE
    +
    +
    +
MM50
  • MM CODE
    MM50
  • FLIGHT ARMORING
    Iron Base Alloy
  • TECHNOLOGY
    TIG
  • ABRASIVE WEAR RESISTANCE
    +
    +
    +
    +
  • CORROSIVE WEAR RESISTANCE
    +
    +
MM560
  • MM CODE
    MM560
  • FLIGHT ARMORING
    Nickel Base Alloy
  • TECHNOLOGY
    PTA
  • ABRASIVE WEAR RESISTANCE
    +
    +
    +
    +
  • CORROSIVE WEAR RESISTANCE
    +
    +
    +
    +
MM570
  • MM CODE
    MM570
  • FLIGHT ARMORING
    Nickel Base Alloy
  • TECHNOLOGY
    PTA
  • ABRASIVE WEAR RESISTANCE
    +
    +
    +
    +
    +
    +
  • CORROSIVE WEAR RESISTANCE
    +
    +
    +
    +
    +
MM830
  • MM CODE
    MM830
  • FLIGHT ARMORING
    Nickel Base Alloy
  • TECHNOLOGY
    PTA
  • ABRASIVE WEAR RESISTANCE
    +
    +
    +
    +
    +
  • CORROSIVE WEAR RESISTANCE
    +
    +
    +
    +
    +
MM4900
  • MM CODE
    MM4900
  • FLIGHT ARMORING
    Molybdenum
  • TECHNOLOGY
    HVOF
  • ABRASIVE WEAR RESISTANCE
    +
    +
    +
    +
    +
  • CORROSIVE WEAR RESISTANCE
    +
    +
    +
    +
MM6000
  • MM CODE
    MM6000
  • FLIGHT ARMORING
    Tungsten Carbide
  • TECHNOLOGY
    HVOF
  • ABRASIVE WEAR RESISTANCE
    +
    +
    +
    +
    +
    +
  • CORROSIVE WEAR RESISTANCE
    +
    +
    +
    +
    +
    +

Repair old worn twin cylinders

Partial reline of single screw cylinders is mostly not cost effective on the contrary to twin cylinders which based on the added value for the customer related to costs an interesting service is.

Repair examples

Honing cylinder oversize
Broken screw repaired temporary
Bad worn cylinder section repaired with new front section.
[ Connect with us ]

Contact Us