What are the dimensions of a 6318 bearing?
Answer
The 6318 is a deep-groove ball bearing: 90 mm bore, 190 mm outside diameter, 43 mm wide.
How it is worked out
- Type
6 → deep-groove ball bearing - Series
63 → series 63 · medium · dimension series 03 - Bore code
18 → 18 × 5 = 90 mm
d = bore code × 5 mm (04+) · 00 = 10 · 01 = 12 · 02 = 15 · 03 = 17 mm
Worth knowing
- In inches
- 3.543 × 7.480 × 1.693 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 6318-2RSH or -2RS1, FAG 6318-2RSR, NSK 6318DDU, NTN 6318LLU.
- ZZ · 2Z · 2ZR
- Metal shield on both sides. Less friction and more speed than a seal, but not watertight. SKF 6318-2Z, FAG 6318-2ZR, NSK and NTN 6318ZZ.
- 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 6318 from any maker fits the same shaft and housing. Seals, cage, clearance and quality are what differ.
Other bores in the 63 series
630010 × 35 × 11 mm630112 × 37 × 12 mm630215 × 42 × 13 mm630317 × 47 × 14 mm630420 × 52 × 15 mm630525 × 62 × 17 mm630630 × 72 × 19 mm630735 × 80 × 21 mm630840 × 90 × 23 mm630945 × 100 × 25 mm631050 × 110 × 27 mm631155 × 120 × 29 mm631260 × 130 × 31 mm631365 × 140 × 33 mm631470 × 150 × 35 mm631575 × 160 × 37 mm631680 × 170 × 39 mm631785 × 180 × 41 mm631995 × 200 × 45 mm6320100 × 215 × 47 mm
Same 90 mm bore, other series
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