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RKB tapered roller bearings, 303 series: dimensions and part numbers

The RKB 303 series of tapered roller bearings brings together 27 part numbers in our catalogue across 27 basic sizes, from 30302 to 30334: bore (d) from 15 to 170 mm and outside diameter (D) from 42 to 280 mm. Every part number in the table links to its own page, where you can request a quote via WhatsApp or email.

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303 series dimension table

RKB tapered roller bearings, 303 series: boundary dimensions in millimetres according to ISO 355 and catalogue part numbers.
Basic designationdDTSame sizeVariants
30302154214.25
30303174715.25
30304205216.25
30305256218.2525x62x18.25
30306307220.7530x72x20.75
30307358022.7535x80x22.75
30308409025.2540x90x25.25
303094510027.2545x100x27.25
303105011029.2550x110x29.25
303115512031.555x120x31.5
303126013033.560x130x33.5
30313651403665x140x36
30314701503870x150x38
30315751604075x160x40
303168017042.580x170x42.5
303178518044.585x180x44.5
303189019046.590x190x46.5
303199520049.595x200x49.5
3032010021551.5
30321105Dimension not validatedDimension not validated
3032211024054.5
3032412026059.5
3032613028063.75130x280x63.75
30328140Dimension not validatedDimension not validated
30330150Dimension not validatedDimension not validated
30332160Dimension not validatedDimension not validated
30334170Dimension not validatedDimension not validated

In 27 of the 27 sizes the basic designation is also listed on its own, without a suffix. To request a quote, send us the full part number marked on the bearing, the box or the drawing.

How to read the part number: 303 gives the bearing type and the dimension series; for the same bore, each series has a different outside diameter and width. What follows is the bore code: from 04 upwards, multiplying by 5 gives the bore in millimetres (in the 30306, 06 × 5 = 30 mm); 00, 01, 02 and 03 stand for 10, 12, 15 and 17 mm.

The table gives the boundary dimensions of each basic designation according to ISO 355, in millimetres: d is the bore, D the outside diameter and T the total width. These are standardised dimensions: the same basic designation has the same dimensions in every brand. Where a dash appears, the dimension has not been validated yet: we confirm it when we quote.

If the part number on the bearing can no longer be read, measure the bore, the outside diameter and the total width, and find the matching row: with that size and the variant you need, we will quote it.

Other RKB tapered roller bearings series

Which RKB 303 series bearing do you need?

Send us the full part number, or the size and the variant, with the quantity: we will quote it via WhatsApp or email.

See all RKB bearings references →

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