Screw flight glossary.

The vocabulary of screw flights is not standardised across languages or industries. This is what we mean by the terms — and what we need from you when you send an enquiry.

The six numbers we need

• Outside diameter (OD) — the diameter of the finished flight, 40 to 3000 mm.
• Inside diameter (ID) — the bore that sits on the shaft or tube, from 20 mm.
• Pitch — the axial advance of one full turn. Our manufacturing limits: pitch ≥ 30 mm, and pitch divided by inside diameter ≤ 6.
• Plate thickness — 2 to 60 mm, constant across the blade on a pressed flight.
• Hand — right hand or left hand. Look along the axis: a right-hand flight advances clockwise away from you.
• Material — the steel grade. If you do not know it, tell us the conveyed product instead.

Terms you will meet

• Sectional flight — one pressed segment, a single turn or a part of one. Constant thickness.
• Helicoid flighting — a continuous helix cold-rolled from strip. Thins towards the outer edge.
• Starts — the number of parallel helices on one shaft. Single start is the norm; multi-start raises throughput at the same pitch.
• Opening angle — the angular extent of a partial segment, when a full turn is not wanted.
• Ribbon flight — a flight carried on standoffs with an open core, for sticky material.
• Profile gauge — the fixture every flight is checked against before dispatch. Pitch and seating, one hundred per cent.
• DIN 15261 — the German standard for screw conveyor flight tolerances. Our pressed segments hold it.

Steel grades in plain words

• S235 / S355 mild steel — the default. Cheap, weldable, wears fast under abrasion.
• Stainless 1.4301 / 1.4571, duplex — food, chemicals, corrosion.
• Hardox 400 / 450 / 500 — abrasion resistance through the section.
• Creusabro — work-hardens in service; tolerant of impact.
• X120Mn12 (1.3401) — manganese steel. Soft until it is struck, then hard.