C340/S-D Rotor Complete
S-groove rotor complete for mixed and non-cotton fibres (Ne 16–40) on the Rieter R923 and R35 semi-automatic platform. Diamond top layer on the prepared substrate. T013 bearing rated to 110,000 rpm with a recommended ceiling of ≤ 90,000 rpm — dimensionally identical to the original, at 40–60% below OEM price.
C340/S-D — Complete Specifications
All measurements in millimetres. Every rotor complete assembly is 100% dynamically balanced on our own balancing line before shipment.
Why S Groove for Blends and Speciality Fibres
The S groove is the speciality profile for blends and non-cotton fibres — a groove shaped for fibre mixes that behave differently from straight cotton in the Ne 16–40 band. Because the count band is not published, the selection is checked against your fibre and target count before quoting.
S Groove — Applicable Yarn Count Range
Aimed at mixed fibre. For 100% cotton at the same counts the G or T groove is the simpler choice. Mills usually run a sample first to verify the groove on the machine before a bulk order.
S Groove — Shaped for Blends and Speciality Fibres
In a blend, fibres of different length and friction travel the groove together. The S profile is shaped so the mixed ribbon stays under control through deposition and twist insertion, which keeps yarn strength and appearance consistent when the blend ratio or the fibre supplier changes. Mills running several fibre types often keep an S-profile rotor alongside their standard cotton rotors.
Tolerant of Lot Variation
Designed to absorb the variation that comes with buying speciality fibre lot by lot.
Right Tool for Speciality Work
Rather than forcing a cotton groove, the S profile is matched to the fibre mix.
Built for Mixed Fibres
Groove geometry adapted to blends, where fibre length and friction differ inside the same ribbon.
Consistent Blend Yarn
Keeps yarn strength and appearance steady when the blend ratio or the fibre supplier changes.
What D Means: Base and Working Surface
The trailing letters of the model code are two independent codes, not one word: B is the substrate, D is the working surface. Diamond top layer (HV 1000-1200) with a friction coefficient of 0.05–0.1, which reduces fibre damage at the groove face. Standard lead time on coated rotors is 7–15 days, with urgent orders on request.
B = boronized (boron-steel) substrate. A diamond film is only microns thick, so the steel underneath decides whether it survives: a soft substrate deforms under fibre and grit impact and the film cracks and spalls off. The boronized base is the hardening step that keeps the diamond layer intact. This code does not carry the B step; it is the -BD- variant that pairs the diamond layer with the boronized base.
D = diamond top layer, grown on the prepared substrate as a micron-scale film. It takes the fibre and grit contact directly, which is where the wear resistance, the friction coefficient of 0.05–0.1 and the anti-stick behaviour come from that hold the groove profile over long runs. Diamond coating technology of US origin, applied on JSM’s own treatment line.
Which Rieter Machines Use C340/S-D?
This rotor runs the T013 bearing, shared by the Rieter R923 and R35 semi-automatic machines. Models in the group differ by groove and rotor size, not by bearing fit.
What to Spin with C340/S-D
How this rotor is applied on Rieter R923 and R35 machines, with the S groove’s count window where one is published.
✓ Applications a straight cotton groove handles poorly
✓ Blends and speciality fibres in the Ne 16–40 band
✓ Viscose, modal and other man-made fibre mixes
◇ 100% commodity cotton — G standard groove
◇ Fine single-fibre counts — T narrow family
◇ Medium–coarse counts Ne 10–30 — U groove
→ TT: Extra narrow (Ne 16–40)
→ S: Special (Ne 16–40) — this model
→ U: General purpose (Ne 10–30)
→ GL: Large (Ne 3–16)
→ G: Standard (Ne 16–40)
→ See all 9 Rieter R923 and R35 rotor models →
C340/S-D — Frequently Asked Questions
Answers to the questions buyers ask most often about this rotor. If yours is not listed, send it with your machine model and current rotor code — we reply within 24 hours.
Is C340/S-D compatible with my Rieter R923 and R35 machine?
What does the model code C340/S-D mean?
What yarn counts does the S groove suit?
What do the letters BD mean in the model code C340/S-D?
How much does an OEM-equivalent rotor save versus the original?
Can I order the rotor spindle or rotor cup separately?
Order C340/S-D Rotors
Pre-filled: C340/S-D · Rieter R923 / R35 · diamond coating
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