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56mm Solid Light Series 20 (Internal gear)

SIG 20 Series (Solid Section Internal Gear)

The SIG 20 Series rings have a constant height of 56mm across the diameter range and the rectangular cross section gives them improved torsional stiffness compared to the flanged bearings, with longer life being the main advantage.

These units are similar to the American KAYDON HS6-N series which feature imperial dimensions and American involute stub gears. 

Within the QCB® range we offer

  • The widest range (metric and inch sizes)
  • Non standard drilling patterns
  • Location diameters as standard
  • Zinc plating, black oxide, painted or nylon coatings for corrosion protection


Full 56SLS20 Series datasheet HERE


             SIG 486 20   SIG 616 20   SIG 716 20   SIG 816 20   SIG 916 20   SIG 1016 20   
             SIG 1166 20


Available on request




From 2014 all QCB®. geared slewing rings are made in 42CrMo4 steel for superior gear strength.

Grease points

Usually supplied with 4 grease points in the outer ring only, DIN 71412A M8x1 equispaced. 

Load and bolt limit curves

Bearings should operate within the prescribed triangular load area at all times. If a combination axial and radial load act on the slewing ring it should be converted to a single equivalent load for graphical analysis.

The bolt limit curve is based on the use of Grade 8.8 bolts. An improvement to this can be achieved by using Grade 10.9 bolts, but only after approval of the NBC Technical Department.

If the load is suspended, or the axis of rotation is not vertical, refer application details to

Units: Y-Axis = moment load in KN.m; X-Axis = Axial load in KN

Interchange information

This information offers generally accepted interchange numbers. However, variations exist and all queries should be referred to our Technical Department for analysis. Dimensional equivalence does not always imply equal performance!


In the quest for continual product improvement this information subject to change without notice. 

Need help?

Contact the NBC Slewing ring experts on +44 (0)1952 222300, by fax on +44 (0)1952 242938 or e-mail

Whilst every effort has been made to ensure the accuracy of the information on this website, if you spot a mistake please inform the Thanks!