Manufacturing – Screws

Parallel Twin Screws

MAGOG design, manufacture and supply a wide range of extrusion screws for Plastic, Rubber, Food and Speciality applications.

When considering new screws our aim is to satisfy 2 criteria.

  1. Improvements in your processing and production
  2. Optimised service life of the screw

Maximising your processing and production is often a combination between screw design and specification.

We help you achieve this through our Process Knowledge and Manufacturing Expertise.

Screw Design Knowledge

Drawing on experience across a wide range of industries and material applications, along with an in depth knowledge and understanding of extruder screw design, our process engineers through consultation with your own process and production specialist will offer screws designs aimed at providing:

Improved Processing

  • Melt Quality
  • Homogeneity
  • Reaction Extrusion Stability

Improved Production

  • Optimum output
  • Efficient power consumption

MAGOG provide screw designs and processing technologies from single start compression screws through to a range of mixing elements for optimised distributive and dispersive mixing.

We are specialists in Parallel and Conical Twin Screws offering a range of designs specifically suitable for Pipe, Profile, Sheet and Compounding applications.

Manufacturing Expertise

Most screws are manufactured from high quality EN41B steel which is a chromium-aluminium-molybdenum nitriding steel.

Conical ScrewsNitriding is a heat treating process that diffuses nitrogen into the surface of the screw, to produce a hard surface on the component. Depending on the size of the screw either a gas or plasma nitride process is used to give an even depth of hardness across the screw profile.

After Nitriding, a minimum surface hardness of 950 Vickers (VPN), equivalent to 68 Rockwell is achieved with a hardness a depth of between 0.4 – 0.6 mm.

Nitrided screws provide a good general purpose component that can be refurbished by MAGOG to standard at a later date.

For more demanding high wear or corrosion applications, in addition to the normal nitriding process, screws can be supplied with additional surface treatments including hard facing on the flight lands or coated to provide the optimum resistance.

Magog offers a number of Hard Facings applied though plasma transferred arc (PTA) or tungsten inert gas (TIG) welding processes.

Weld applied Hard facing grades include:

  • Cobalt- Base Hard-surfacing Alloy
  • Nickel-Base Hard-Surfacing Alloy with Chromium Boride
  • Specialist High Speed Tool Steel

Further coatings can be provided including:

  • Stainless Steel inlays
  • Tungsten Carbide
  • Chromium Carbide
  • Chrome plating with addition of Ceramic coating



Process Knowledge ~ Manufacturing Expertise ~ Engineering Excellence