Designation system

The designations of Y-bearing units are made up of
  • a prefix for the type and material of the housing
  • a size identification
  • a suffix identifying the incorporated bearing
  • other suffixes identifying other features.
Y-bearing unit designation examples are shown in fig 1. The meaning of the various letters and numbers are explained in the order in which they appear.

Unit and housing prefixes

These prefixes comprise from one to six letters. The following list of prefixes which appear in the product tables is given in alphabetical order.
FYFlanged Y-bearing unit/housing, cast iron, square flange, four bolt holes
FYCFlanged Y-bearing unit/housing, cast iron, round flange, four bolt holes
FYJFlanged Y-bearing unit/housing, cast iron, square flange, four bolt holes, to JIS standard
FYKFlanged Y-TECH bearing unit/housing, composite, black coloured, square flange, four bolt holes
FYKCFlanged Y-TECH bearing unit/housing, composite, white coloured, square flange, four bolt holes
FYTFlanged Y-bearing unit/housing, cast iron, oval flange, two bolt holes, cannot be relubricated
FYTBFlanged Y-bearing unit/housing, cast iron, oval flange, two bolt holes
FYTBKFlanged Y-TECH bearing unit/housing, composite, black coloured, oval flange, two bolt holes
FYTBKCFlanged Y-TECH bearing unit/housing, composite, white coloured, oval flange, two bolt holes, with grease nipple
FYTFFlanged Y-bearing unit/housing, cast iron, oval flange, two bolt holes, cannot be relubricated
FYTJFlanged Y-bearing unit/housing, cast iron, oval flange, two bolt holes, to JIS standard
PY-bearing plummer block unit/housing, pressed steel
PFY-bearing flanged unit/housing, pressed steel, round flange, three or four bolt holes
PFDY-bearing flanged unit/housing, pressed steel, triangular flange, three bolt holes
PFTY-bearing flanged unit/housing, pressed steel, oval flange, two bolt holes
SYY-bearing plummer block unit/housing, cast iron
SYFY-bearing plummer block unit/housing, cast iron, short base
SYFJY-bearing plummer block unit/housing, cast iron, short base, to JIS standard
SYJY-bearing plummer block unit/housing, cast iron, to JIS standard
SYKY-bearing plummer block unit/housing, composite, black coloured
SYKCY-bearing plummer block unit/housing, composite, white coloured, with grease nipple
TUY-bearing take-up unit/housing, cast iron
TUJY-bearing take-up unit/housing, cast iron, to JIS standard

Size identification

The size identification for Y-bearing units is the bore diameter of the incorporated Y-bearing
  • for metric shafts in millimetres uncoded, e.g. SY 25 TF;
  • for inch shafts in inches uncoded, e.g. SY 1.1/2 TF.
For the housings, the 2 of the bearing series designation is replaced by 5 followed by the size identification of the incorporated bearing, e.g. SYJ 508 is intended for a bearing with a 40 mm bore (and its inch-size variants).
Pressed steel housings have the outside diameter of the bearing for which they are designed in millimetres uncoded e.g. PF 52.

Identification of Y-bearing incorporated in unit

This identification takes the form of suffixes comprising two or three letters and describes the bearing incorporated in the unit.
FMY-bearing of series YET 2 (inner ring extended at one side, eccentric locking collar), standard seal without flinger at each side
KFY-bearing of series YSA 2-2FK (inner ring extended at both sides, tapered bore), standard seal + plain flinger at each side
KR
Y-bearing of series YSA 2-2RFK (inner ring extended at both sides, tapered bore), standard seal + rubberized flinger at each side
NTHY-bearing of series YAR 2-2RF/HV (inner ring extended at both sides, grub screw locking), standard seal + rubberized flinger at each side, stainless steel bearing
NTRY-bearing of series YAR 2-2RFG/VE495 (inner ring extended at both sides, grub screw locking), bearing outer ring with lubrication groove, standard seal + rubberized flinger at each side, bearing rings zinc coated, non-toxic grease fill
PFY-bearing of series YSP 2-2F (SKF ConCentra stepped sleeve), standard seal + plain flinger at each side
RMY-bearing of series YAT 2 (inner ring extended at one side, grub screw locking), standard seal without flinger at each side
TF
Y-bearing of series YAR 2-2F (inner ring extended at both sides, grub screw locking), standard seal + plain flinger at each side
TR
Y-bearing of series YAR 2-2RF (inner ring extended at both sides, grub screw locking), standard seal + rubberized flinger at each side
WFY-bearing of series YEL 2-2F (inner ring extended at both sides, eccentric locking collar), standard seal + plain flinger at each side
WRY-bearing of series YEL 2-2RF (inner ring extended at both sides, eccentric locking collar), standard seal + rubberized flinger at each side

Identification of other features

So-called V-numbers are used to identify other features which differ from the standard design and for which other standard suffixes are not available, or where several standard suffixes would otherwise be needed to describe the features. Those used for Y-bearings and Y-bearing units include
AHAnti-rotation pin, solid feet and loose alignment torque
VA201Y-bearing/unit for extreme temperatures (–40 to +250 °C) with pressed steel cage and lubricant paste
VA228Y-bearing/unit for extreme temperatures (–150 to +350 °C) with special "coronet" cage of graphite
VE495Y-bearing with zinc coated bearing rings and special non-toxic grease
VL065Y-bearing with zinc coated inner ring
VL086Y-bearing with zinc coated bearing rings and zinc coated locking collar