The mounting dimensions are 17x40x12 mm and the weight is 0.07 kg; technical details beyond these are shown in the specification table. This variant features a contact seal. Where an assembly is not opened again after joining, the mounted state is the final result — and its scatter decides how uniform a production series turns out. This version combines two features that concern different properties, and it is worth keeping them apart.
The contact seal on both sides determines what enters the rolling chamber and what leaves it: it keeps moisture and fine dust away, holds the grease charge dimensioned for the service life inside the bearing, and in return produces a load-independent frictional torque and limits the permissible speed. Normal radial clearance with narrowed tolerances, by contrast, determines none of that; it reduces the scatter of the clearance within the normal class and thereby acts on the properties that depend on the residual clearance — radial stiffness, axial mobility under load, vibration behaviour and the size of the load zone in the mounted state.
The frictional torque of this version is dominated by the lip and changes only slightly through the narrower clearance distribution; anyone seeking a reproducible breakaway force will find it here not in the clearance class but in the design of the seal. The combination makes sense where a closed, maintenance-free position is assembled in series and its mounted state can no longer be adjusted: the seal secures the ambient conditions, the narrowed tolerance secures the sameness of the units.
The choice of class itself is not replaced by it — interference fit, frictional heat of the seal and external temperature gradient still consume the same share as under the undivided normal clearance, and where that share is large, a wider clearance class remains the applicable answer. Through-hardened standard bearing steel supplies the hardness and dimensional accuracy on which a narrow distribution can rest at all; the temperature limit of the sealing material is to be taken from the designation.
ManufacturerNACHI
Bearing typeDeep-groove ball bearings
Bore d17 mm
Outer Ø D40 mm
Width B12 mm
Dyn. load C9.55 kN(Catalogue value, not verified)
Stat. load C₀4.8 kN(Catalogue value, not verified)
Reference speed18,000 min⁻¹(Catalogue value, not verified)
Weight0.07 kg
Sealscontact seals on both sides
Clearancenormal radial internal clearance, narrowed range
Cagepressed steel cage
Materialstandard bearing steel
Tolerancetolerance class P0/PN (ABEC 1)
Bore typecylindrical bore
€3.39/ pc
incl. VAT, plus shipping · price drops with quantity
In stock
Typically ready to ship in 1–2 days
In stock · ships via DPD, UPS or Deutsche Post
QtyUnit priceDisc.
1 – 4€3.39—
5 – 9€3.29−3 %
10 – 24€3.22−5 %
25 – 49€3.12−8 %
50 – 99€3.05−10 %
4 more for −3% volume discount
From 100 pcs: price and lead time on request – subject to review.
Total (1 pc)€3.39
NACHI 6203-2NSE9CM Kugellager (17x40x12)
— 17 x 40 x 12 mm
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Same dimensions means the same bearing type and matching main dimensions (d × D × B). Sealing, cage, internal clearance and execution (e.g. material, precision, grease fill) are encoded in the suffix and may differ — please check before ordering. Equivalent additionally means the same sealing, internal clearance and tolerance class; the cage and other suffix features (e.g. lubrication groove) may differ.
