ITH Roundnuts RMS / RMZ
The stress-optimized design of ITH Roundnuts RMS and RMZ achieves higher bolt pre-tensioning forces (up to 40% more) than with comparable DIN hexagon nuts which is confirmed by scientific studies. The design is certified by German Lloyds. ITH RMS / RMZ are built to work with ITH Bolt Tensioning Cylinders from the range of M24 to M100 (7/8'' to 4''). The ITH Roundnuts are produced in:
- ITH RMS : ITH round nut hexagon version
- ITH RMZ: ITH round nut two-flat version
Even customized applications are possible. Both versions are also available in a flat version "ITH RMS / RMZ slim line".
ITH Round nuts can achieve up to 40% higher preloads
- which allows the designer to reduce the fastener sizes which saves costs
- Higher bolt spacing n: The flange diameter can be reduced which saves costs
Certified design
- by German Lloyds
- Designed for use with ITH Bolt Tensioning Cylinders
Applications, advantages and explaining the design of ITH Roundnuts
The certified ITH-round nuts are used in combination with the ITH Stretch-Method. The round nuts can replace standard hexagon nuts ISO 4032, DIN 934 and DIN 6915.
Application: Inner ring slew bearing
The smaller outer diameter of the ITH round nut (here ITH RMZ M60) reduces the bolt spacing and the number of bolts at the ring flange. For this reason, the flange thickness can be clearly reduced and the flange can be made more compact which reduces costs. Higher pre tensioning forces were achieved by using the ITH round nut RMZ.
Application: Inner ring slew bearing
With chamfers in the support of the ITH bolt tensioning cylinders they are easier and faster to handle in the assembly process.
Application: Outer ring slew bearing
The slew bearing application in total. In this application we applied 4 different bolt tensioning cylinders at the outer ring at the same time for simultaneously pre tensioning force (ITH-multi tensioning). The 4 bolt tensioning cylinders were linked together in one hydraulic circuit and connected to the ITH hydraulic pump ITH Aero-MAX 9).
Application: Outer ring slew bearing
After applying the full hydraulic pressure the ITH Round nut is adjusted by a hand torque wrench with a defined torque value for the RMS round nuts.
ITH round nuts achieve higher pre tensioning forces
The high degree of reproducibility in the pre-tensioning force is achieved by special geometric factors. Scientific studies have shown that when ITH-round
nuts are used, the pre-tensioning force in bolts is 40% higher than with DIN hexagon nuts.
Material savings
The life span of the bolt is increased by the use of ITH round nuts because the notch stresses on the first loadbearing thread of the bolt are substantially lower
than when standard hexagon nuts are used.
Cost reduction compared to a standard-nut
With ITH round nuts RMS / RMZ, it is possible to reduce the tensioning factor of the tool (α factor to 2230 VDI). ITH-round nuts reduce costs, because fewer of them are required in comparison to standard hexagon nuts and the plant has a higher degree of process reliability.
Surface coatings
ITH round nuts can be supplied with special coatings (zinc lamination, galvanized, Dacromet)
Cost reduction 1:
- In comparison to conventional hexagon nuts, fewer ITH RMS / RMZ nuts can be used by achieving the same pre load force (n hexagon nuts > n ITH RMS / RMZ)
Cost reduction 2:
- The ITH RMS / RMZ can be used with the same amount of nuts to achieve a higher pre load force in the bolt connection. The bolt connection can be designed in a more effective way and therefore the material costs are reduced.
Further advantages:
- Higher security
- Smaller contact pressure of the bolts
- Higher repeatability of the pre load forces by using the ITH bolt tensioning cylinders
- Possible reduction of the tightening factor αA
- Certified design by the German Lloyd
Contact your local person in charge
Use the ITH global network to find your local person in charge.
Objective technical advice
Being a whole system supplier we are not determined to one specific bolting method - Therefore we advise you objectively and offer the best technical and cost-effective solution.
Contact us for a free consultation
Contact us on any questions regarding your bolt connection or for any technical questions. We advise you free of charge and offer a free on-site inspection.