What are the dimensions of a 6811 bearing?

Answer 55 × 72 × 9 mm

The 6811 is a deep-groove ball bearing: 55 mm bore, 72 mm outside diameter, 9 mm wide.

Change the numbers →

How it is worked out

Type6 → deep-groove ball bearing
Series68 → series 68 · ultra-thin · dimension series 18
Bore code11 → 11 × 5 = 55 mm

d = bore code × 5 mm (04+) · 00 = 10 · 01 = 12 · 02 = 15 · 03 = 17 mm

Worth knowing

In inches: 2.165 × 2.835 × 0.354 in. A metric bearing: inch-series bearings (R8, 1600…) do not fit the same shaft.
2RS · 2RS1 · 2RSH · DDU · LLU: Rubber seal on both sides, greased for life. Best against dirt and water, slightly more drag. The same bearing by brand: SKF 6811-2RSH or -2RS1, FAG 6811-2RSR, NSK 6811DDU, NTN 6811LLU.
ZZ · 2Z · 2ZR: Metal shield on both sides. Less friction and more speed than a seal, but not watertight. SKF 6811-2Z, FAG 6811-2ZR, NSK and NTN 6811ZZ.
RS · Z: Seal (RS) or shield (Z) on one side only, the other side open: for bearings fed oil or grease by the machine.
C3: Internal clearance larger than normal. Standard on electric motors and wherever the shaft runs hot or the fit is tight. Replace a C3 with a C3.
Interchangeable?: Yes. ISO 15 fixes the bore, outside diameter and width, so a 6811 from any maker fits the same shaft and housing. Seals, cage, clearance and quality are what differ.

Other bores in the 68 series

680010 × 19 × 5 mm 680112 × 21 × 5 mm 680215 × 24 × 5 mm 680317 × 26 × 5 mm 680420 × 32 × 7 mm 680525 × 37 × 7 mm 680630 × 42 × 7 mm 680735 × 47 × 7 mm 680840 × 52 × 7 mm 680945 × 58 × 7 mm 681050 × 65 × 7 mm 681260 × 78 × 10 mm

Same 55 mm bore, other series

601155 × 90 × 18 mm 621155 × 100 × 21 mm 631155 × 120 × 29 mm

Do it with your own numbers

Got a number off a bearing with suffixes on it? Paste it into the bearing number decoder: it reads the whole designation, seals and clearance included.

Keep it on the wall

This answer is one row of the printable bearing size chart — one A4 or Letter page, free, no sign-up.