At 20x52x15 mm and a unit weight of 0.14 kg, the installation envelope is fixed; further technical details are held in the specification table. Where the no-load torque is measured and checked against a limit, the scatter of the clearance is one of the few quantities the design can fix at all. In this version the two features complement one another in a way that shows up in the frictional torque.
The non-contact seal follows the contour of the inner ring with an elastomeric sealing body down to a narrow distance without touching it; this removes the contribution that dominates breakaway and no-load torque in a contact version — and removes its scatter with it, since a lip is subject to manufacturing tolerances of its contact pressure and to a wear that changes over the operating period.
What then remains are the grease charge and the load distribution in the rolling contact, and the load distribution is a direct consequence of the residual clearance: it determines how many balls carry at the same time and how the outer ring settles relative to the inner ring under load. Normal radial clearance with narrowed tolerances reduces the scatter of that quantity within the normal class without shifting the range, so that no-load torque, radial stiffness and vibration behaviour lie closer together across a production series.
Applications in which this counts check those values on the finished product and can no longer adjust them after joining. The choice of class is not replaced by it: interference fit and temperature gradient still consume the same share as under the undivided normal clearance, and where that share is large, a wider class remains the applicable answer.
The gap of the seal does not permanently hold back liquid and very fine dust; the grease charge is enclosed and dimensioned for the service life. Through-hardened standard bearing steel supplies the hardness and dimensional accuracy on which a narrow distribution can rest.
ManufacturerNACHI
Bearing typeDeep-groove ball bearings
Bore d20 mm
Outer Ø D52 mm
Width B15 mm
Dyn. load C15.9 kN(Catalogue value, not verified)
Stat. load C₀7.9 kN(Catalogue value, not verified)
Reference speed14,000 min⁻¹(Catalogue value, not verified)
Weight0.14 kg
Sealsnon-contact 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
€4.13/ 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€4.13—
5 – 9€4.00−3 %
10 – 24€3.92−5 %
25 – 49€3.79−8 %
50 – 99€3.71−10 %
4 more for −3% volume discount
From 100 pcs: price and lead time on request – subject to review.
Total (1 pc)€4.13
NACHI 6304-2NKE9CM Kugellager (20x52x15)
— 20 x 52 x 15 mm
Response within 4 business hours
✓Free shipping over €100 · 14-day returns
✓Purchase on invoice – first order paid before dispatch, then 14-day terms for approved business customers
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.
