Sectional flighting is manufactured from steel plate, cut as donut blanks and pressed into a helix with uniform thickness from inner to outer edge, then butt-welded one rotation at a time to a center pipe [S2][S3]. Helicoid flighting is cold-rolled as a single continuous helix from a flat steel strip, a process that work-hardens the surface and leaves the flight thicker at the root and tapered toward the tip [S1][S2][S5].
These two manufacturing routes produce flights with different gauges, different cost structures, and different material options, which is why almost every screw conveyor spec question eventually lands on the same decision: pick the cold-rolled helix for volume and economy, or pick the welded plate helix for thickness, abrasion resistance, and alloy flexibility [S1][S5][S7].
How Each Flighting Is Actually Built
Helicoid flighting is produced on rolling machines with cone-shaped dies that deform a continuous steel strip into a single helix; the compression work-hardens the OD surface, controls diameter, pitch, and thickness closely, and yields a one-piece flight with minimal scrap [S1][S3][S5]. The finished helix is mounted on a center pipe and fastened with intermittent skip welds, with internal collars plug-welded at each end to take a coupling shaft [S1].
Sectional flighting starts as plate steel: a CNC plasma or cut table burns donut blanks to the specified ID and OD, a press forms each blank into one pitch of helix, and the individual flights are fitted and butt-welded to the center pipe one rotation at a time [S2][S3][S5]. Because each flight is a separate piece, plate thickness, alloy, and pitch can be varied flight-by-flight, which is how sectional screws end up in mining, quarry, and heavy industrial service [S1][S4][S5].
Gauge, Tolerance, and Stock Size Reality
Sectional flighting is available in heavier thicknesses than helicoid flighting, and that is the single most cited engineering reason to specify it [S1]. KWS Manufacturing's published stock tables show helicoid flight thicknesses ranging from 3/16 in. on a 4-in. diameter screw up to 7/16 in. on a 16-in. diameter screw, while the equivalent sectional line starts at 12 gauge (about 0.105 in.) on a 6-in. screw and scales upward [S1]. Helicoid flights also use a tapered profile because the rolling process thins the OD, whereas sectional flights hold uniform thickness from ID to OD [S2][S3][S5].
Dimensional tolerance differs in kind, not just degree: helicoid screws benefit from closely controlled diameter, pitch, and thickness on a continuous process [S1]; sectional screws rely on accurate blank cutting plus press setup, and suppliers such as Bega explicitly state their tolerance margins exceed the CEMA standard [S4]. For standard horizontal conveyors, a sectional flight with pitch equal to diameter is the conventional default [S4].
Material Options and Wear Behaviour
Helicoid flighting is constrained to the steels that can be cold-rolled, predominantly carbon and stainless strip, with limited ability to swap alloys mid-run [S2][S3][S5]. Sectional flighting can be cut and formed from mild steel, abrasion-resistant plate (commonly AR200, AR400, AR500), galvanized steel, stainless steel, aluminum, Hastelloy, Monel, and Inconel, which makes it the only realistic option for highly abrasive or corrosive service [S2][S5].
Because sectional flights can be produced from hardened AR plate and accept much heavier gauges than helicoid, they dominate heavy-duty and abrasive applications even at higher unit cost [S1][S2][S5]. For a broader carbon-steel-versus-stainless-versus-AR400 selection view on the same equipment class, see Screw Conveyor Materials: Carbon Steel vs Stainless vs AR400. Helicoid's work-hardened surface and smooth OD help it handle fine or sticky materials with less carry-back, which is why grain, ice, pellet, and similar light-duty services still specify helicoid [S1][S2][S3].
Cost, Labour, and Lead-Time Trade-Off
Helicoid flighting is more cost-effective than sectional because the rolling process requires minimal labour once the machine is set, generates very little scrap, and produces a one-piece flight with few potential failure points [S3][S5][S7]. Sectional flighting is more expensive in labour terms: every flight is handled, fitted, and welded individually, and the welds at each joint are the visible aesthetic and inspection penalty [S2][S5].
That cost gap is the reason most general-purpose horizontal conveyors with diameters from 4 in. through 16 in. and standard CEMA pitches are still quoted as helicoid unless the material is known to be abrasive [S1][S2][S7]. Where abrasion is a factor, the higher sectional cost is normally written off against longer flight life and easier in-situ repair, since a single worn sectional flight can be cut out and re-welded without scrapping the whole screw. For a related decision lens on conveyor equipment selection criteria, see Screw Conveyor for the broader component and drive context.
Decision Matrix: Helicoid vs Sectional
Putting the two side by side on the criteria that actually drive a screw conveyor RFQ: (1) Thickness range, helicoid typically tops out near 7/16 in. at 16-in. diameter while sectional scales from 12 gauge up to AR500 plate and beyond, so sectional wins abrasive service [S1][S2][S5]; (2) Profile uniformity, sectional is constant ID-to-OD, helicoid tapers thinner at the OD, so sectional wins predictable wear [S2][S3][S5]; (3) Cost and lead time, helicoid is cheaper and faster because rolling is continuous and low-skill, sectional adds plate cutting, pressing, and per-flight welding [S3][S5][S7]; (4) Material flexibility, sectional accepts AR plate, stainless, and high-nickel alloys, helicoid is effectively limited to cold-rollable carbon and stainless strip [S2][S3][S5]; (5) Suitability for fine or sticky material, helicoid's smooth work-hardened surface reduces carry-back, so helicoid wins grain, pellet, and similar light-duty service [S1][S2][S3].
Use sectional when the material is abrasive, the duty is heavy, or a non-standard alloy is required, and use helicoid when the service is light-to-moderate, the material is fine or sticky, and standard CEMA sizing is acceptable [S1][S2][S3][S5][S7]. For related bulk-handling equipment geometry, see Belt Conveyor and Chain Conveyor for how the same abrasive-duty logic carries over to other conveyor classes.
Limitations and Failure Modes to Plan For
Helicoid flighting is limited to standard CEMA sizes, and thickness and pitch are constrained by the rolling machine's geometry, so non-standard diameters or pitches are not practical on helicoid [S2][S3][S5]. Customization on helicoid is effectively impossible without a dedicated rolling setup, which is why specialty services tend to drift to sectional [S2][S5].
Sectional flights carry more potential failure points because every joint is a weld, and weld quality controls fatigue life on heavy-duty units [S5]. Tapered or variable-pitch sectional screws can leave residual material in the trough if the casing is not also tapered to match, which is a documented operational limitation rather than a defect [S4]. Shaftless and heavy-mineral designs that share the same flight-versus-shaft logic are covered separately under Screw Pump and the related Lead Screw geometry, where the same thickness-versus-cost logic applies to the screw element rather than the flight.
Trackable Signals for the Next Build
Two signals are worth tracking on the next screw conveyor RFQ: confirm whether the supplier can cut sectional flights from AR400 or AR500 plate at the specific ID/OD required, since plate availability often gates lead time more than flight-forming capacity [S2][S5]; and verify the CEMA diameter, pitch, and gauge tables against the published KWS-style stock list before releasing a purchase order, because helicoid thickness is hard-capped by the rolling process while sectional thickness is gated only by plate availability [S1].