Trust the Expert: S2S Industries

+1 (514) 228 - 1660


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Shaftless Screw (Spiral)

We supply all industry standards of shaftless spirals as well as made to order screws that can be used for your new projects, or as replacement parts for existing shaftless screw conveyors, sludge conveyors, screw feeders, screw presses, inclined shaftless screw conveyors, vertical shaftless screw conveyors or any other equipment using shaftless screws. Our machine is capable of rolling the thickest and tightest flights.

shafltess screw for conveyor compactor or augermultiple shaftless screws  shaftless screw w/ brush

To get a quick history of the shaftless screw conveyor, you can read our article Origin of the Shaftless screw.

Shaftless spirals are normally used to convey sticky materials in centreless screw conveyors. The spiral lays on liners and is driven at one end by a gear box. A shaftless spiral will allow the movement of more materials than a shafted of the same size.

As there is no shaft or hanger bearings, the material runs free without the problems of sticking to, or wrapping around the shaft. The shaftless conveyor can be up to 90 meters and can run in either direction. Vertical, Inclined, Horizontal, Pushing, Pulling, are being used in all kinds of applications: municipal waste, sludge screw, sand screw, screenings, pulp and paper, breweries, and many others. With a wear liner of UHMW giving smooth running, little or no noise, making for a quiet safe working environment.




Procedure to order a shaftless spiral


Right hand/Left hand, Push or Pull

Your spiral can either be a right hand or a left hand.

Your spiral can be pushing, pulling or both, A pushing spiral is conveying material away from the gear box. A pulling spiral is conveying material toward the gear box.

When ordering a spiral, we need to know if your spiral is a "Right hand (RH) pushing", "RH pulling", "LH pushing" or "LH pulling".

 drawing push or pull screw for conveyor


The material for your spiral can be stainless steel (300 series and duplex), Mild steel (coated, plated or not), harder steel, or any special request (including Swedish steel) (all special request proposed by our clients are evaluated on the specific needs of the client).


The total length for the shaftless spiral can be given to S2S Industries. We deliver "per section" of 4 meters in average (to be welded or bolted together by the client.) We can possibly deliver in smaller sections (more welds for the client) or longer sections upon special inquiries.

Single flights

A single flight spiral is characterized with the following dimensions:

  •  The outside diameter (OD)
  •  The pitch (linear distance between two flights)
  •  The section of the ribbon: height (A) and thickness (B) 

single flight left hand right hand screw for conveyor

Multiple flights

dual bar stainless steel shaftless screw dual bar stainless steel shaftless screw dual bar stainless steel shaftless screw welding close up dual bar stainless steel shaftless screw

A double (or multiple) flight is characterized with the following dimensions:

  •  The outside diameters (OD)
  •  The pitch (linear distance between two flights)
  •  The type of multiple spiral
  •  The section of the base ribbon: height (A) and thickness (B)
  •  The section of the tip/insert/reinforcement ribbon: height (C) and thickness (D)

multiple flights drawing screw conveyor

Coupling discs

Your spiral is coupled to the drive shaft with a coupling disc (or End plate.) S2S Industries always includes "torsion bars" at the connection between the spiral and the coupling disc. A coupling disc is characterized with the following dimensions:

  •  The outside diameter (OD) (usually the same as the spiral OD)
  •  The thickness
  •  The center hole diameter (drive shaft diameter)
  •  The number of bolt holes
  •  The bolt holes diameter
  •  The distance from bolt holes to disc center hole


Questions? Want a quotation? Feel free to contact us, we will be pleased to help you!