How Archimedes Screws Are Manufactured and Why Lead Times Do Not Have to Be Six Weeks
Archimedes screws are one of the oldest machines in engineering, and they're still everywhere. On water treatment sites they lift raw sewage and storm water at inlet works. On energy-from-waste (EfW) plants, screw conveyors move ash, residues and reagents. When one wears out or fails, the process it serves usually stops with it.
The usual answer from manufacturers is a lead time of six weeks or more. For a plant that's already down, or running on a single stream, that's a long time to wait. It doesn't have to be.
How an Archimedes screw is made
Every screw is built from the same core parts: a central tube or shaft, the helical flights welded around it, and stub shafts at each end that sit in the bearings. Manufacture follows a clear sequence.
- Measure and design. We start from the existing screw, a drawing or site measurements. The key dimensions are outside diameter, pitch, flight thickness, centre tube size, overall length and the stub shaft details.
- Cut the flight blanks. Flights begin as flat, ring-shaped blanks profile-cut from plate. Each blank makes one turn of the helix.
- Form the flights. The blanks are pressed or drawn into a helical shape to the correct pitch.
- Fit and weld. The formed flights are positioned along the centre tube, joined to each other and welded to the tube. Getting the pitch consistent along the full length is where experience matters.
- Machine the stub shafts. End shafts are turned, keyed and fitted to suit the existing bearings and drive.
- Check and finish. We check straightness, run-out and dimensions before the screw is painted or coated to suit its duty.
Wear is the main enemy, so material and flight thickness should match the duty. Abrasive grit, ash or residue may justify thicker flights or a wear-resistant edge. A like-for-like copy of a screw that wore out early isn't always the best answer.
Why lead times run to six weeks
Long lead times rarely come from the welding itself. They come from queues: waiting for a production slot, waiting for material, waiting for drawings to be approved, and transport if the screw is built overseas. Each step adds days that have nothing to do with making the part.
How we shorten them
IME Fabrication builds screws in our own workshop in Hutton, Essex. That means:
- One team, one workshop. Cutting, welding and machining happen under one roof, so there's no waiting for subcontractors.
- We work from what you have. If there's no drawing, we can measure the old screw and produce one.
- No overseas shipping. The finished screw travels by road from Essex to your site.
- Engineers who fit as well as fabricate. IME's site teams can remove the old screw and install the new one, so you deal with one contractor from start to finish.
Plan ahead and save even more time
The fastest replacement is the one you ordered before you needed it. If you run screws on a critical duty, ask us to measure and draw them now. With an approved drawing on file, fabrication can start much sooner.
IME works to ISO 9001, ISO 14001 and ISO 45001, and supports EfW and water treatment sites across the UK with a 24/7 call-out service.
Frequently asked questions
What is an Archimedes screw used for?
In water treatment, Archimedes screw pumps lift raw sewage and storm water at inlet works. On EfW plants, screw conveyors move ash, residues and reagents. Both use the same principle: a rotating helix moving material along or up a trough.
Can a worn Archimedes screw be repaired?
Sometimes. Worn flight edges can be built up or replaced in sections if the centre tube is in good condition. If wear is widespread or the tube is distorted, a new screw is usually better value.
Can an Archimedes screw be made without the original drawing?
Yes. A replacement can be reverse engineered by measuring the existing screw and producing a new drawing. Keeping that drawing on file makes any future replacement quicker.
Contact us on 0208 5996570 or team@imegroup.co.uk to talk through your Archimedes screw requirements.