Y-bearing unit data


HousingsBearings
Dimension
standards
Boundary dimensions in accordance with:
  • ISO 3228:2013
    • SY .. M series
    • SY .. U series, except of the centre height H1 for SY 514 U
    • SYH series, except for the centre height H1, which is lower than the standard
    • SYK series
    • P series, except for the centre height H1, which deviates slightly
    • SYWK .. Y series
    • SYWR series
  • JIS B 1559:2009
    • SYJ series
    • SYWK .. L
  •  no standard (neither national nor international), but common in the marketplace
    • SYM series
    • SYF series
    • SYFJ series
    • SYFWK series
    • SYFWR series
Bearing data
Tolerances

Cast, composite and stainless steel housings

Shaft centre height H1 (fig. 1):

  • d ≤ 40 mm
    → ±0,25 mm
  • d > 40 mm
    → ±0,30 mm

The outside diameter of the bearing is matched to it's seat in the housing so that the outer ring is prevented from turning, but still able to compensate for misalignment.

Bearing data
Radial internal clearanceBearing data
Materials

Cast iron

  • SY(J), SYH, SYM and SYF(J) series
    • grey cast iron EN-GJL-HB235 in accordance with EN 1561:2011

Composite

  • SYK series
    • glass fibre reinforced PA6
    • "moulded in" steel coil reinforcement

Pressed steel

  • P series
    • cold-rolled sheet steel, chromium6+ free zinc-coated

Composite for SKF Food Line

  • SYWK .. Y series
    • glass fibre reinforced PA6
    • "moulded in" steel coil reinforcement
  • SYWK .. L and SYFWK series
    • glass fibre reinforced PBT

Stainless steel

  • SYWR and SYFWR series
    • cast austenitic stainless steel (AISI 300 series)
Materials for rolling bearings
MisalignmentBearing data
SKF logo