What are the dimensions of a 6909 bearing?
Answer
The 6909 is a deep-groove ball bearing: 45 mm bore, 68 mm outside diameter, 12 mm wide.
How it is worked out
- Type
6 → deep-groove ball bearing - Series
69 → series 69 · thin-section · dimension series 19 - Bore code
09 → 09 × 5 = 45 mm
d = bore code × 5 mm (04+) · 00 = 10 · 01 = 12 · 02 = 15 · 03 = 17 mm
Worth knowing
- In inches
- 1.772 × 2.677 × 0.472 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 6909-2RSH or -2RS1, FAG 6909-2RSR, NSK 6909DDU, NTN 6909LLU.
- ZZ · 2Z · 2ZR
- Metal shield on both sides. Less friction and more speed than a seal, but not watertight. SKF 6909-2Z, FAG 6909-2ZR, NSK and NTN 6909ZZ.
- 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 6909 from any maker fits the same shaft and housing. Seals, cage, clearance and quality are what differ.
Other bores in the 69 series
Same 45 mm bore, other series
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.
Get the next chart before it's on the site
The Shop Sheet, once a month: one new printable chart, and one standards gotcha that catches people out — the kind of wrong number a forum thread or an AI answer gives with total confidence. No sales emails.