31-XGM-BD-AE Rotor Complete
Standard-profile rotor complete for everyday cotton counts (Ne 16–40) on the Rieter R40 fully automatic platform. BD build — boronized base under a diamond top layer. 100% dynamically balanced and dimensionally identical to the original — at 40–60% below OEM price.
31-XGM-BD-AE — Complete Specifications
All measurements in millimetres. Every rotor complete assembly is 100% dynamically balanced on our own balancing line before shipment.
Why XGM Groove for Everyday Cotton Spinning
The G standard groove is the workhorse geometry for cotton counts in the Ne 16–40 band — a balanced deposition zone that keeps medium and medium-fine yarns running evenly, shift after shift. Rotors in this group share that groove and differ by cup diameter, so the groove can stay constant while the count moves.
XGM Groove — Applicable Yarn Count Range
Sits in the middle of the Ne 16–40 band. For the finest counts move to the narrow T family; for coarse counts (Ne 3–16) the GL groove is the match. Mills usually run a sample first to verify the groove on the machine before a bulk order.
XGM Groove — The Balanced Standard Profile
The G profile spreads fibre deposition across a medium-width groove, which is what keeps medium counts predictable when the raw-material lot changes. Rotors in this group differ mainly by cup diameter, so a mill can hold the groove constant while moving up or down the count range. Rotors in this family differ mainly by cup diameter, so the groove can stay the same while the count moves.
Matched to Ne 16–40
The groove volume is sized for the fibre mass of 16–40 Ne cotton, so fibre collection stays in the stable part of the curve across the whole band.
Even Yarn, Run to Run
A medium-width deposition zone holds the fibre ring steady between doffs, which is what keeps count and appearance consistent in routine production.
Fewer End Breaks
Twist propagation through a standard-profile groove avoids the tension spikes that appear when a rotor is pushed outside its count band.
Clean-Running Profile
The groove cross-section resists micro-dust build-up, reducing the periodic faults that otherwise show up after long continuous runs.
What BD 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. This code is a two-layer build: B puts a boronized (boron-steel) substrate under the film, D is the diamond top layer. The base is what stops fibre impact from deforming the rotor and cracking the coating. 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.
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 31-XGM-BD-AE?
The R40-AE bearing locks this rotor to the Rieter R40 platform. Rotors from a different bearing group will not interchange, however similar the cup looks.
What to Spin with 31-XGM-BD-AE
Typical operating profile for the XGM groove on the Rieter R40 fully automatic platform. Groove count windows follow the catalogue data.
✓ Ne 16–40 — the mainstream of a cotton spinning schedule
✓ Carded and combed cotton on fully automatic platforms
✓ Viscose and modal blends inside the same count band
◇ Medium–coarse counts Ne 10–30 — U groove
◇ Coarse counts Ne 3–16 — GL groove, large-diameter rotors
◇ Abrasive or high-impurity fibre — specify DN diamond coating
→ T: Narrow (Ne 16–40)
→ TT: Extra narrow (Ne 16–40)
→ S: Special (Ne 16–40)
→ U: General purpose (Ne 10–30)
→ GL: Large (Ne 3–16)
→ See all 9 Rieter R40 rotor models →
31-XGM-BD-AE — 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 31-XGM-BD-AE compatible with my Rieter R40 machine?
What does the model code 31-XGM-BD-AE mean?
What yarn counts does the XGM groove suit?
What do the letters BD mean in the model code 31-XGM-BD-AE?
How much does an OEM-equivalent rotor save versus the original?
Can I order the rotor spindle or rotor cup separately?
Order 31-XGM-BD-AE Rotors
Pre-filled: 31-XGM-BD-AE · Rieter R40 · boronized base + diamond coating
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