FIG 20 Imperial Series

A flange profile outer and a geared inner ring separated by a 3/4" ball set; a constant section height of 2.025" and a standard range of external diameters ranging from 20.39" to 47.17" matching American dimension, gearing and bolt patterns

All QCB® slewing rings are manufactured to the highest possible quality levels in ISO certified factories. A QCB® Quality Standard defines all aspects of their dimensions and tolerances as well as all aspects of manufacturing from materials properties, all stages of production, as well as packing and labelling.

Whilst the data on the site is updated regularly, we reserve the right to implement subtle changes to these standards in our quest for continual product improvement.


  • Industrial positioners (e.g. welding assemblies and jigs)
  • Ship or truck loading chutes and swivels
  • Stretch wrapping machines
  • Conveyors and other materials handling equipment
  • Simple amusement rides

If the IMPERIAL sizes and bolt patterns are not quite right, consider the FIG20 Metric series.

Need help?

Our technical team have many years of experience and are happy to assist with selection. Call or e-mail them for fast, efficient and professional advice.

The Design Form will assist you in defining your application details.


QCB referenceOutline dimensions & weight



FIG 518 20 61 AA LM20.39012.85017.87016.22016.1401 65
FIG 648 20 61 AA LM25.51017.60022.99021.34021.2602 90
FIG 748 20 61 AA LM29.45021.60026.93025.28025.2003 106
FIG 848 20 61 AA LM33.39025.60030.87029.22029.1404 121
FIG 948 20 61 AA LM37.32029.13334.80033.15033.0705 148
FIG 1048 20 61 AA LM41.26033.13338.74037.09037.0106 165
FIG 1198 20 61 AA LM47.17039.13344.65043.00042.9207 188
QCB referenceOuter holesInner holes20o spur gear
LanaLiniPDPzFz MAX
in lb.f
FIG 518 20 61 AA LM19.250814.8801213.2504537883
FIG 648 20 61 AA LM24.3801019.6301518.0004727883
FIG 748 20 61 AA LM28.3801223.6301822.0004887883
FIG 848 20 61 AA LM32.2501527.6301826.00041047883
FIG 948 20 61 AA LM36.2501831.5001829.66738910500
FIG 1048 20 61 AA LM40.1301835.5002033.667310110500
FIG 1198 20 61 AA LM46.0001841.5002439.667311910500
Standard grease fitting# at least 2x 1/4"-28 UNF 2B on outer ring

Interchange information

The FIG20 Imperial Series is interchangeable with bearings from other manufacturers such as Rotek, Kaydon, AVON, Silverthin . However there may be variations to this rule (e.g. OEM variants) and we invite you to refer to our technical staff for assistance.

FIG 518 20 61 AA LMRK6-16N1ZL6-16N9ZSK6 16 NZ716 MB1
FIG 648 20 61 AA LMRK6-22N1ZL6-22N9ZSK6 22 NZ721 MB1
FIG 748 20 61 AA LMRK6-25N1ZL6-25N9ZSK6 25 NZ725 MB1
FIG 848 20 61 AA LMRK6-29N1ZL6-29N9ZSK6 29 NZ729 MB1
FIG 948 20 61 AA LMRK6-33N1ZL6-33N9ZSK6 33 NZ733 MB1
FIG 1048 20 61 AA LMRK6-37N1ZL6-37N9ZSK6 37 NZ737 MB1
FIG 1198 20 61 AA LMRK6-43N1ZL6-43N9ZSK6 43 NZ742 MB1

Custom designs

  • Double drilled or custom drilling patterns
  • Higher precision bearings with location diameters
  • Reduced internal clearance (Class 5 & Class 6)
  • Black oxide or zinc plating for enhanced corrosion protection
  • Epoxy paint or even Nylon coated units to special order
  • Stainless steel or aluminium versions


All geared slewing rings are manufactured in 42CrMo4 V steel to offer superior gear strength over some other brands.

Internal construction

Standard FIG20 Imperial Series bearings incorporate plastic spacers, but ball spacers, steel or brass spacers, or even full complement and caged designs can be supplied for specific applications.


A land riding NBR (nitrile rubber) seal strip is standard. VITON seals can be supplied to order.


The FIG20 Imperial Series has a standard 20° pressure angle, uncorrected spur gear cut into the inner ring.


QCB® Slewing rings are assembled with a small quantity of Lithium EP2 grease. It is important that all slewing rings are greased during installation and prior to operation. FIG20 Imperial Series slewing rings will usually have 4 or 6 grease nipples DIN 71412 M8x1 on the radial face of each ring. Sufficient grease nipples for all holes as well as Nylon plugs (to insert if a grease nipple is not required) are supplied with each ring.

Special greases can be supplied on demand as can GreaseMax Automatic Lubricators and Accessories.

Load & Bolt limit curves

If both a radial and an axial load act on the bearing these must be combines into a single equivalent load to enable basic selection from the load curves. The raceway limit is illustrated by the blue line, the red line illustrates the limit for the specified number of Grade 10.9 bolts.The load point should be well under the relevant load curve for long life.

Grade 8.8 bolts can be used but only after approval by our technical team.

Similarly if the load is suspended or the axis of rotation is not vertical please refer the application details to us and take advantage of our decades of experience!

QCB referencePDF printCAD.dwgMODEL.STP
FEG 518 20 61 AA LMFIG 518 20 61.pdfFIG 518 20 61.dwgFIG 518 20 61.STP
FIG 648 20 61 AA LMFIG 648 20 61.pdfFIG 648 20 61.dwgFIG 648 20 61.STP
FIG 748 20 61 AA LMFIG 748 20 61.pdfFIG 748 20 61.dwgFIG 748 20 61.STP
FIG 848 20 61 AA LMFIG 848 20 61.pdfFIG 848 20 61.dwgFIG 848 20 61.STP
FIG 948 20 61 AA LMFIG 948 20 61.pdfFIG 948 20 61.dwgFIG 948 20 61.STP
FIG 1048 20 61 AA LMFIG 1048 20 61.pdfFIG 1048 20 61.dwgFIG 1048 20 61.STP
FIG 1198 20 61 AA LMFIG 1198 20 61.pdfFIG 1198 20 61.dwgFIG 1198 20 61.STP

Associated Products

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