C344/U-D Rotor Complete
General-purpose rotor complete for medium to coarse counts (Ne 10–30) on the Rieter R923 and R35 semi-automatic platform. Diamond top layer on the prepared substrate. 73-1-69 bearing rated to 80,000 rpm with a recommended ceiling of ≤ 72,000 rpm — dimensionally identical to the original, at 40–60% below OEM price.
C344/U-D — Complete Specifications
All measurements in millimetres. Every rotor complete assembly is 100% dynamically balanced on our own balancing line before shipment.
Why U Groove for General-Purpose Spinning
U is the flexible profile. Its wider zone covers the Ne 10–30 band, so one rotor keeps working when the count schedule shifts and fewer change-overs are needed. The model is selected on the application, so the bearing fit and the count window are confirmed together.
U Groove — Applicable Yarn Count Range
Covers a wide band around Ne 10–30. Above Ne 30 the narrow T family takes over. Groove and cup size are confirmed together when the order is placed.
U Groove — Flexibility Across the Schedule
General-purpose geometry is about tolerance. The U groove holds fibre collection steady across mixed fibre lots and a range of medium-to-coarse counts, keeping yarn strength consistent between deliveries and holding rotor swaps down. Mills that run several counts per machine usually standardise on this profile.
One Rotor, Several Orders
Mixed-order mills can keep the same rotor in place as the schedule moves inside the band.
Straightforward Economics
A flexible rotor that reduces both change-out labour and the number of lines carried as spares.
Wide Count Window (Ne 10–30)
A broad operating band means fewer rotor changes when the count schedule shifts, cutting machine downtime.
Stable Fibre Collection
The wider deposition zone holds collection steady across mixed fibre lots, keeping yarn strength consistent between deliveries.
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. The D in the code is the diamond top layer — the face that takes the fibre and grit contact. On the -BD- models that same layer sits on a boronized base. Every assembly is 100% dynamically balanced before it leaves the balancing line.
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 C344/U-D?
The 73-1-69 bearing fixes this rotor to the Rieter R923 and R35 semi-automatic platform. It is one of 6 rotor models sharing that bearing group.
What to Spin with C344/U-D
Typical operating profile for the U groove on the Rieter R923 and R35 semi-automatic platform, at speeds up to 80,000 rpm.
✓ Mills wanting a simple, low-inventory spare-parts line
✓ General-purpose profile, medium to coarse yarns
✓ Medium–coarse counts, Ne 10–30
◇ Abrasive or recycled fibre — DN diamond coating
◇ Strictly single-count fine spinning — XTC extra-narrow
◇ Fine yarns Ne 30–40 — T narrow family
→ T: Narrow (Ne 16–40)
→ TT: Extra narrow (Ne 16–40)
→ S: Special (Ne 16–40)
→ U: General purpose (Ne 10–30) — this model
→ GL: Large (Ne 3–16)
→ See all 6 Rieter R923 and R35 rotor models →
C344/U-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 C344/U-D compatible with my Rieter R923 and R35 machine?
What does the model code C344/U-D mean?
What yarn counts does the U groove suit?
What do the letters BD mean in the model code C344/U-D?
How much does an OEM-equivalent rotor save versus the original?
Can I order the rotor spindle or rotor cup separately?
Order C344/U-D Rotors
Pre-filled: C344/U-D · Rieter R923 / R35 · diamond coating
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