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Slewing rings

For over 25 years, Rima slewing rings have proven their worth in the most varied areas of application: from earthmoving machinery to lifting equipment and renewable energy production.

For every field of application we have the right option in our catalogue. We manufacture four-point contact slewing rings single or double row, ungeared, inner geared or outer geared, and bearings with or without a flange.

Each slewing ring can also be customised in diameter and dimensions, drilling pattern, gear and heat treatments.


Design and production flexibility is the guiding key with which we work alongside customers in the sector to identify innovative and effective solutions.

We communicate with our customers daily, understanding their needs, and offering expert advice for tailor made solutions.

It is possible to customise the slewing rings in every detail, from material characteristics to the definition of loads, dimensions, diameters, from the type of toothing to the definition of the number of teeth, from lubrication points to drilling patterns and even heat and surface treatments.

Characteristics and loads
Diameter and number of teeth
Lubrication points
Drilling Patterns
Heat treatments

Slewing ring loads

The slewing rings can be subjected simultaneously to radiai and axial forces together with a tilting moment.The slewing rings internal shape, the fastening system and the rings materiai are choosen based on the loads and the product application

Our Technical Department has developed a calculation program that works on 5 grades of freedom for applied forces: an axial force, two radiai forces and two tilting moments.

The internal shape of slewing rings is achieved in order to avoid non hertzian contacts in presence of static and dynamic loads.

Construction materials

Rings composition

C45 (normalised, hardened and tempered)

Correspondence chart between Italian, European and non-european regulations
UNI 7845/78 7874/79 EURONORM 83/70 DIN AFNOR A 35 551 A BS 970-1/72 970-2/70 AISI – SAE
STANDARD 17200/69 W Nr
C 45 2C45 Ck45 1191 XC48 080M46 1045

42 CrMo4 (normalised, hardened and tempered)

Correspondence chart between Italian, European and non-european regulations
UNI 7845/78 7874/79 EURONORM 83/70 DIN AFNOR A 35 551 A BS 970-1/72 970-2/70 AISI – SAE
STANDARD 17200/69 W Nr
42 CrMo4 42 CrMo4 42 CrMo4 7225 42CD4 708A42 En 19c 4140
Rolling elements 100Cr6 HRC 63 ± 3

Rolling elements

100Cr6 HRC 63 ± 3



The most common grease used is lithium based (Ep) and corresponds to the standard: DIN 51825 K2K – 20 ed ISO L-X-BCHA2.

It is also possible to use equivalent grases. The operating temperatures are between -20° C and +120° C. For low temperature applications, special greases must be used. The greasing must be completed as per the slewing rings application. Listed below are some of the equivalent greases recommended:


Beacon EP2


Mobilux EP2




Calithia EP2

Heat treatments

The rotating ring ofthe slewing ring spreads the loads to the raceway; this is calculated and verified based on the Hertz Theory and the modem system of plasticity. The hardening treatment is applied based on our calculation facts and the specifics of slewing ring application.

Hardening treatment on gear is possible when this is necessary or strictly required by the customer.

Teeth side hardening

Raceway hardening

Specialisation and expertise

Synergy is our strength. Interaction between mechanics and hydraulics, between innovation and experience, different sectors and skills allow us to create solutions for different markets.

From small gardening machinery to large construction machinery. We design and manufacture ballbearing turntables and slewing rings for renowned names in agriculture, construction, green economy, forestry, logistics and lifting markets.


Industrial trailers

Logistics trailers

Know how and production technologies

Sirca Sa is one of Gruppo Rima production site and is located in Pietra Neamt, Romania. Sirca manages all the processing phases of the ballbearing turntables and slewing rings, from raw materials quality check to the painting.

The continuous improvement of the systems and their customization with flexible technologies combined with a deep engineering knowledge, allow us to build complex and extremely specific components with maximum reactivity and adaptability to the needs and standards of the market.

Ballbearing turntables

Are you looking for a light-duty slewing ring? See the page dedicated to our ballbering turntables.

The advanced technology used in production and the certification of the manufacturing process make GRUPPO RIMA product’s exceptionally reliable in terms of construction and performance and appreciated in the trailer market due to their precision and reliability.

Hundreds of customers (both OEM market leaders as well as end users) have chosen to equip their machines throughout the years with GRUPPO RIMA products entrusting their trailers to their high standard quality and durability.

Our I90-Series and I90/2-Series are our ball bearing turntables for industrial applications, operating at speeds exceeding 60 km/h. We have two lines with one or two rows, both with a 90 mm high profile and with a diameter from 900 to 1300 mm.

Industrial ballbearings

We design and manufacture Z-profile ballbearing turntables with a diameter between 400 and 1100 mm and with a profile of 52 or 60 mm high. Each ballbearing turntable can be customised on request with specific diameters, profile, holes, greases and materials.


We design and manufacture ballbearing turntables for light applications with a diameter between 300 and 1200 mm and with a profile from 55 to 90 mm high. Each ballbearing turntable can be customised on request with specific diameters, profile, holes, greases and materials.

For agriculture

Are you looking for a custom designed product?

We have always differentiated ourselves for the very high customization in small and large lots

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