At 17x40x12 mm and a unit weight of 0.064 kg, the installation envelope is fixed; further technical details are held in the specification table. This variant features increased radial clearance (C3). Speed and heat can be treated separately here: the seal design sets no limit on the speed, the clearance class takes from the warming its effect on the rolling contact.
This combination stands out in that its two features act independently of one another, which simplifies the design work. The non-contact seal follows the contour of the inner ring with an elastomeric sealing body down to a narrow distance without touching it: no load-independent frictional torque arises, no heat source at the inner ring and no wearing contact point, so the permissible speed lies close to that of the open form and the barrier effect is retained over the operating period.
Increased clearance (C3) holds an allowance ready for the shares that consume the mounted clearance in service — the interference fit on the shaft and the temperature gradient between a warmer inner ring and an outer ring coupled through the housing. Because the sealing takes no part in that gradient, it originates here in the surroundings of the position: in a hot shaft, an adjacent process or the power lost in a fast-running drive.
That makes the estimate of the residual clearance in the warm running state more direct than in a version sealing by contact, where part of the warming arises inside the bearing itself. It remains to be observed that the gap does not permanently hold back liquid and very fine dust, and that the grease charge is enclosed and dimensioned for the service life, so its ageing at the elevated operating temperature can become the limiting quantity.
At low radial load the wider clearance has to be taken into account, because the load zone turns out narrower. Through-hardened standard bearing steel sets the frame for hardness and dimensional accuracy; the temperature limit of the sealing material is to be taken separately from the designation.
ManufacturerNTN
Bearing typeDeep-groove ball bearings
Bore d17 mm
Outer Ø D40 mm
Width B12 mm
Dyn. load C10.6 kN(Catalogue value, not verified)
Stat. load C₀4.6 kN(Catalogue value, not verified)
Limiting speed21,000 min⁻¹(Catalogue value, not verified)
Reference speed18,000 min⁻¹(Catalogue value, not verified)
Weight0.064 kg
Sealsnon-contact seals on both sides
Clearanceradial internal clearance greater than normal
Cagepressed steel cage
Materialstandard bearing steel
Tolerancetolerance class P0/PN (ABEC 1)
Bore typecylindrical bore
€5.01/ 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€5.01—
5 – 9€4.86−3 %
10 – 24€4.76−5 %
25 – 49€4.61−8 %
50 – 99€4.51−10 %
4 more for −3% volume discount
From 100 pcs: price and lead time on request – subject to review.
Total (1 pc)€5.01
NTN 6203 LLBC3/5K Kugellager (17x40x12)
— 17 x 40 x 12 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.
