Bearing Inserts

Single row ball bearings with a convex spherical outer diameter generally used with pressed steel or cast iron housings commonly referred to by their registered trade names of SKF "Y-bearings" or RHP "Self Lubes".

  • Imperial or metric shaft sizes
  • Grub screw locking, single or double row eccentric locking or taper sleeve designs
  • Tri-lip seal designs available for wet and dirty environments
  • Stainless steel inserts to match our Thermoplastic and Stainless steel housings

Features of bearing inserts

  • Ball bearing with spherical outside diameter
  • A wide range or inch or metric bores locked onto the shaft by means of setscrews, eccentric locking collars or taper bush adapters
  • Contact seals, flinger seals or triple lip seal configurations
  • Considered sealed for life in many applications

Allowable running speeds

The allowable speed for bearing inserts is defined by the quality of support offered by the shaft.

shaft d (mm)200 Series300 Series
Shaft toleranceShaft tolerance
j7 (h9/IT5)h7h8h9j7 (h9/IT5)h7h8h9
126700530038001400----
156700530038001400----
176700530038001400----
206000480034001200----
255600400030001000500036002600900
30450034002400850430030002200800
35400030002000750380028002000700
40360026001900670340024001700630
45320024001700600300022001500560
50300022001600560260020001400500
55260020001400500240018001300450
60240018001200450220017001100430
65220017001100430200015001100400
70220016001100400190014001000360
7520001500100038018001300900340
801900140095034017001200850320
851800130090032016001100800300
901700120080030015001100750280
95----14001000700260
100----1300950670240
105----1200900630220
110----1200800600200
120----1100750530190
130----1000670480180
140----900600430160

Shaft tolerances

Setscrew inserts are generally mounted with a loose fit for easy installation. For most normal industrial applications the shaft tolerances below should suffice.

Shaft d Allowable deviation in shaft diameter (µm)
low speed low-medium speed medium-high speed highest speed
mm h9 h8 h7 j6 h6
over incl. max/min max/min max/min max/min max/min
10 18 0 / -43 0 / -27 0 / -18 +8 / -3 0 / -11
18 30 0 / -52 0 / -33 0 / -21 +9 / -4 0 / -13
30 50 0 / -62 0 / -39 0 / -25 +11 / -5 0 / -16
50 80 0 / -74 0 / -46 0 / -30 +12 / -7 0 / -19
80 120 0 / -87 0 / -54 0 / -35 +13 / -9 0 / -22

At high speeds or under heavy load, setscrew inserts should be fitted with a tight fit with shaft tolerances indicated below

Shaft dAllowable deviation in shaft diameter (µm)
medium-high speedmedium-heavy loadhigh speedheavy load
mmm6m7n6n7
overincl.max/minmax/minmax/minmax/min
1018+18 / +7+25 / +7+23 / +12+30 / +12
1830+21 / +8+29 / +8+28 / +15+36 / +15
3050+25 / +9+34 / +9+33 / +17+42 / +42
5080+30 / +11+41 / +11+39 / +20+50 / +20
80120+35 / +13+48 / +13+45 / +23+58 / +23

For bearings with an adapter sleeve an h9 or even h10 shaft tolerance can be used.


Bore tolerance

The insert bore tolerance of inserts is tabulated below

d Δ dmp Kia Δ Bs
mm μm μm μm
over incl. high low max high low
10 18 +18 0 12 0 -120
18 30 +21 0 15 0 -120
30 50 +25 0 1 0 -120
50 80 +30 0 22 0 -150
80 120 +35 0 28 0 -200
120 180 +40 0 35 0 -250

d - Nominal bore diameter

Δdmp - The deviation of a single plane mean bore diameter of the inner rings

Kia - The radial runout of the assembled bearings inner ring

ΔBs - The deviation of a single width of inner ring


Setscrew tightening torque

The recommended setscrew torques are listed below

Setscrew sizeTightening torque
mminchNmibf.in
M5x0.8No10-32 UNF3.1628
M6x11/4-28 UNF34 - 430 - 35.4
M8x15/16-24 UNF7.8 - 8.369 - 73.5
M10x1.253/8-24 UNF16.3 - 17.2144 - 152
M12x1.257/16-20 UNF26.5 - 27.4235 - 243
M14x1.51/2-20 UNF33.4 - 34.3296 - 304
M16x1.55/8-18 UNF54 - 54.9478 - 486

Overtightening is a common cause of "failure"


Adapter sleeve inserts

After installing the insert, adapter sleeve with locking washer and nut on the shaft , it is usually sufficient to tighten the insert by hand, and then an extra 2/5 - 3/5 of a revolution.

If the insert does not clamp down on the shaft, ensure the adapter size matches the nominal shaft diameter.


Eccentric locking collar inserts

When locked to the shaft in the direction of rotation, the collar will automatically tighten further by the action of the working radial loads. The setscrews are then tightened.

In applications with reversing shafts, a double eccentric locking collar will be required.


High axial load applications

The axial load carrying capacity of the insert will be limited by the quality of fit between insert and shaft.

If a high axial load is to be supported a shoulder should be machine into the shaft against which the insert is fitted. Drilling into the shaft to improve setscrew performance may add unwanted stress multipliers.

In such applications, check the housing is capable of carrying the load in the direction required. The housing tear out strength is not necessarily equal to the carrying capacity of the bearing insert.


Lubrication

Standard bearing inserts are factory filled with a lithium EP2 grease and have an operating temperature range of -20 to +120 °C. In many applications they can be considered "sealed for life".

However, in some applications relubrication is advisable. A guide is tabulated below

dn valueEnvironmentTemp CRelube interval
< 40 000Clean-15 to +656 - 12 months
+65 to +1002 - 6 months
<70 000Clean-15 to +652 - 6 months
+65 to +1001 month
AnyDirty< 651 week - 1 month
> 651 day - 2 weeks
Very dirtyAny1 day - 1 week
Water splashAnyDaily/ Constant

Any good quality lithium or lithium/calcium EP2 grease can be used, and better performance will be achieved with a more modern grease such as a Calcium-sulphonate grease in extremely wet applications.

Associated Products


LUBRICANTS

Ensure an adequate supply of the correct grease to prolong slewring ring life

Lubricants

GreaseMax Auto Lubricators

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