JSM rotor 33 XT BD AE open-end spinning rotor
Rieter R40 · Fully Automatic · R40-AE Bearing

33-XT-BD-AE Rotor Complete

33-XT-BD-AE XT · Narrow · Fine

Narrow T-profile rotor complete for the fine end of the count range (Ne 16–40) on the Rieter R40 fully automatic platform. BD two-layer build: hardened substrate, diamond face. Dimensionally identical to the original part and supplied at 40–60% below OEM price, with balancing verified on our own line.

Groove Type XT — Narrow
Rotor Cup Diameter Ø 33 mm
Coating boronized base + diamond coating
Bearing R40-AE · Rieter R40
Technical Data

33-XT-BD-AE — Complete Specifications

All measurements in millimetres. Every rotor complete assembly is 100% dynamically balanced on our own balancing line before shipment.

Model Number33-XT-BD-AE
Rotor Cup DiameterØ 33 mm
Groove TypeXT — narrow profile for fine and medium-fine counts
CoatingBD — B: boronized (boron-steel) substrate · D: diamond top layer (HV 1000-1200, friction coefficient 0.05–0.1)
Bearing TypeR40-AE — bearing standard for the Rieter R40 platform
Compatible MachinesRieter R40 (fully automatic rotor spinning)
Suitable Yarn CountNe 16–40 — fine and medium-fine counts
Fibre TypeCotton (carded and combed) · viscose · modal · fine-count blends
Balancing Standard100% dynamic-balanced · vibration-checked before packing
OEM CompatibilityDimensionally identical to the original Rieter part — direct drop-in replacement
Price Advantage40–60% below the OEM original part price at equivalent dimensional accuracy
Rotor GroupOne of 9 rotor models in the R40-AE group (31–41 mm diameter range)
Minimum OrderFlexible — sample orders accepted for quality verification
Lead TimeStandard 7–15 days · urgent orders available on request
Groove Engineering

Why XT Groove for Fine Yarn

T-profile rotors run a narrow groove for a reason: at fine counts the fibre ribbon is thin, and a tighter deposition zone keeps it under control through twist insertion. The group is stocked across several cup sizes, which lets a mill shift counts without changing the spinning-box setup.

XT Groove — Applicable Yarn Count Range

Best kept inside Ne 16–40. If the schedule runs coarser than Ne 16, the U or GL groove will run more comfortably. Coating grade and count band are confirmed with the quotation for this rotor.

XT groove · Ne 16–40
Ne 3Ne 10Ne 16Ne 24Ne 30Ne 40Ne 60+
XT groove coverage (Ne 16–40)
Coarse 3–16 Ne  ·  Medium 16–30 Ne  ·  Fine 30–40 Ne
XT

XT Groove — Where Fine Counts Are Decided

At fine counts every extra millimetre of groove width costs yarn quality. The narrow T profile keeps the fibre ribbon tight against the groove wall, giving uniform twist propagation and a smoother yarn surface. Evenness, not operating width, is what a narrow profile is bought for.

≈

Smooth Yarn Surface

Even fibre distribution at insertion gives a smoother yarn face — the property that decides how fine knits look and feel.

↗

Tuned to Ne 16–40

A narrow zone matched to thin fibre ribbons keeps collection stable across the whole fine-count band.

≡

Better Evenness at Fine Counts

Tighter deposition control is what holds thin and thick places down when the yarn gets fine — the effect buyers notice first.

↓

Lower Break Rate

Smoother twist propagation at fine counts cuts the tension peaks that break ends at high rotor speeds.

Surface Engineering

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. B and D do different jobs — B hardens the base, D takes the wear. Tell us your fibre and the speed you run and we confirm both before a bulk order. Ordering rotors, bearings and opening rollers together keeps freight and coating consistent across the spin box.

B — Boronized base
In this code · Substrate layer
Substrate hardening
Boronized / boron steel Supports the D layer Fibre impact

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 coating
In this code · Working surface
HV 1000-1200
CVD diamond film Friction 0.05–0.1 Anti-stick

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.

Compatibility

Which Rieter Machines Use 33-XT-BD-AE?

R40-AE is the bearing standard for this rotor on the Rieter R40 spinning box. A rotor from another group will not seat correctly.

✓ Rieter R40 — R40-AE bearing
Fully automatic platform. 33-XT-BD-AE is one of 9 rotor models in the R40-AE group (31–41 mm diameter range).
✗ R40-EC — the second R40 rotor group
Same R40 machine, different bearing: see the R40-EC models such as 31-XG-BD-EC and 46-XTC-BD-EC.
✗ R60-AE1 / R60-EC1 — newer generation
The R60 rotor groups use their own bearings and rotor sizes (28–40 mm) and do not interchange with R40 rotors.
✗ Rieter R923 / R35 / R36 / R37
Semi-automatic platforms running T013 or 73-1-69 bearings with C-series and S-series rotor codes.
Application Guide

What to Spin with 33-XT-BD-AE

How this rotor is normally applied on Rieter R40 machines, with the XT groove’s published count window where the catalogue documents one.

Where This Rotor Wins
✓ Fully automatic platforms running fine-count delivery
✓ Fine and medium-fine counts, Ne 16–40
✓ Cotton, viscose and modal at the fine end
✓ Fine knitting and shirting-type yarns
Consider Another Groove For
◇ Blends and speciality fibres — S groove
◇ Coarse counts Ne 3–16 — GL groove
◇ Extremely fine compact counts — XTC extra-narrow groove
◇ Abrasive or recycled fibre — DN diamond coating
Groove Options in This Catalogue
→ U: General purpose (Ne 10–30)
→ GL: Large (Ne 3–16)
→ G: Standard (Ne 16–40)
→ T: Narrow (Ne 16–40) — this model
→ TT: Extra narrow (Ne 16–40)
→ S: Special (Ne 16–40)
→ See all 9 Rieter R40 rotor models →
FAQ

33-XT-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 33-XT-BD-AE compatible with my Rieter R40 machine?
33-XT-BD-AE uses the R40-AE bearing, which is the rotor standard for the Rieter R40 platform. It is one of 9 rotor models in the R40-AE group (31–41 mm diameter range). If your spinning box runs a different bearing series the rotor will not interchange — send us your machine model and current rotor code and we confirm within 24 hours.
What does the model code 33-XT-BD-AE mean?
33 is the rotor cup diameter in millimetres — Ø33 mm. XT is the groove, a narrow profile for fine and medium-fine counts. In the code, B is the boronized (boron-steel) substrate and D the diamond top layer. The code ends with the bearing identifier: the R40-AE bearing for the Rieter R40 platform.
What yarn counts does the XT groove suit?
The XT profile covers Ne 16–40, fine and medium-fine counts. Outside that band, ask us — a different groove family is usually the cheaper answer than running this one off its design point.
What do the letters BD mean in the model code 33-XT-BD-AE?
Read the two letters separately. B describes the base: a boronized or boron-steel substrate — a hardening step, not a coating. D describes the working surface: a diamond film (HV 1000-1200) with a friction coefficient of 0.05–0.1, grown on the prepared substrate. B protects the film, D takes the wear. Which one your code carries tells you whether the substrate hardening is present (BD) or whether the rotor runs the diamond layer alone (D).
How much does an OEM-equivalent rotor save versus the original?
Our rotor complete assemblies are supplied at 40–60% below the OEM original and balanced to the same dimensional specification. Standard lead time is 7–15 days; ask for freight options with the quotation.
Can I order the rotor spindle or rotor cup separately?
Cup, spindle and bearing are all available separately. Tell us the rotor code on the machine and which part is worn, and we quote the most economical replacement.
Get a Quote

Order 33-XT-BD-AE Rotors

Pre-filled: 33-XT-BD-AE · Rieter R40 · boronized base + diamond coating

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