Shaftless Spirals

The heart of any conveying system is the shaftless spiral. Without a properly designed and manufactured spiral, the remainder of the fabricated pieces can be compromised. ML offers the strongest and most robust alloy steel spirals manufactured from high tensile alloy steels, cold formed in a multitude of close tolerance diameters and pitches, up to 762 mm (30 inch) in diameter, and greater, and in a variety of bar sizes as large as 120 x 30 mm (4.8 inches x 1.2 inches).

  • Availability of various Brinnell hardness (BHN ) spirals for special applications
  • Availability of various stainless steels (SS) for food and other hygienic applications
  • Engineering support for horizontal, inclined and vertical conveying, as well as storage, un-loading and loading applications.
  • Spiral application technology supported by US and European patents
  • Original design replacement and spare parts for Conveyor systems manufactured by Spaans Babcock, Spaans Bulk Handling Systems, Asdor, US Filter, Siemens as well as other shaftless and shafted Conveyor manufacturers.
  • Replacement spirals, liners and other parts for any conveyor manufacturer. ML offers the largest range of screw diameters available.
  • Mill certificates are mandatory for all alloy steel spiral orders. ML spirals are manufactured from special micro-alloyed Swedish steels.

Our two stage forming process ensures desired diameter, pitch and tolerances between 1%. Each formed subsection of a spiral is factory welded into the required length. All ML spirals are beveled on both ends to ensure proper welded connections. The benefits of the ML alloy steel are greater torque resistance, greater tensile strength, better resistance to twisting and superior wear characteristics resulting in longer spiral life. The close manufacturing tolerances result in fewer wear points on a liner.


Single Spiral

A single spiral (without insert) is described with the following criteria:

  • The outside diameter (OD)
  • The pitch (distance between adjacent flights). Many Many manufacturers only offer pitch equal to diameter.
  • Bar size, if known. Bar size determines inside diameter.

Spirals are usually manufactured in right hand configuration, but can be made left handed. Spirals may be utilized in pushing, pulling or reversing manner. Spirals can be made with or without an insert (second spiral) depending on the design application.


Double Spiral

A single spiral with insert (double) is described with the following criteria:

  • The outside diameter (OD)
  • The pitch (linear distance between two flights)
  • Bar Sizes, if known.

Spirals are usually manufactured in right hand configuration, but can be made left handed. Spirals may be utilized in pushing, pulling or reversing manner. Spirals can be made with or without an insert (second spiral) depending on the design application.

A triple spiral configuration is also available.



  •  BioMass / BioFuels