Press-fitting silentblocks and rubber–metal components is an axial assembly operation in which control over force introduction, alignment and support directly determines whether the rubber layers and metal inserts can be placed without delamination or permanent deformation.
Rubber–metal components react strongly to local overloading, misalignment and variation in interference. The pressing operation must therefore proceed in a stable, linear and reproducible manner. A hydraulic workshop press is suitable when this operation falls within the specific technical boundary conditions.
This page defines when press-fitting silentblocks and rubber–metal components falls within this application range – and when it does not.
When is a hydraulic workshop press suitable?
A hydraulic workshop press is suitable for press-fitting silentblocks and rubber–metal components when:
- the operation is fully axial, without rotation or impact loading
- the pressing force can be built up gradually and constantly
- the component can be supported stably over its entire length and circumference
- the rubber–metal bond remains within allowable deformation
- the required pressing force is predictable and reproducible
- force introduction takes place exclusively via the metal part of the component
When one or more of these conditions cannot be ensured, the application falls outside the intended technical range of a workshop press.
Technical considerations
Pressing force & force build-up
The required pressing force is determined by:
- interference
- diameter
- metal bushing geometry
- elastic response of the rubber
Important requirements:
- force build-up must take place step by step
- shock loading must be avoided
- increase in resistance must be followed directly (indication for misalignment or rubber compression outside tolerances)
- the maximum force must remain below the limit that causes delamination or cracking
Rubber has a non-linear compression modulus. When pressure rises too quickly locally, the load shifts to the rubber–metal bond, causing microcracks that only become visible under dynamic loading.
Interference, alignment & support
A stable stroke geometry requires:
- exact axial alignment before building up force
- loading via the metal outer or inner sleeve, never via rubber parts
- full support of the housing to avoid torsion and tilting
- exclusion of any lateral component in force introduction
- use of sleeves and pressing tools that follow the load-bearing surface exactly
A misalignment of a few tenths of a millimetre leads to asymmetrical rubber compression. The rubber springs back, but the metal sleeve shifts permanently, causing the component to build up stresses that affect the function of the suspension element.
Structural requirements for the press
A suitable workshop press has:
- a welded steel frame with minimal lateral deflection
- linear guidance with constant stroke geometry
- pressing tools that load only the metal support surface
- a flat and stable working table that prevents deformation of housing parts
- sufficient mass to dampen microvibrations and force peaks
When the press column or the frame deflects (>0.3–0.5 mm), a lateral force component arises that places the rubber under an uneven stress field. This is a known cause of premature delamination
What is often underestimated in practice
- sensitivity of rubber layers to local overloading
- influence of minimal misalignment on the rubber–metal bond
- permanent deformation due to overly rapid force build-up
- incomplete support of arms or housings
- variation in interference between seemingly identical components
- initial compression of the rubber that temporarily distorts the force curve
These factors determine whether the component remains within functional tolerances and dynamic load capacity after assembly.
Typical operations within this application
- press-fitting silentblocks into control arms
- assembly of rubber–metal bushings in chassis and suspension parts
- rework of suspension components
- press operations in maintenance and workshop environments
- series assembly of rubber–metal components
This list describes the nature of the operation – not which press configuration is required.
Relation to press classes (HD programme)
Classification within the HD programme is determined by:
- interference
- component diameter
- required force band
- stiffness of the housing structure
Light-duty press class (20–60 tonnes)
Suitable for:
- smaller silentblocks
- thin-walled parts with low to medium interference
- configurations in which axial support can be realised easily
Medium-duty press class (80–160 tonnes)
Suitable for:
- typical rubber–metal components in chassis and suspension parts
- standard workshop and rework operations
- operations in which reproducible force build-up is necessary
Heavy-duty press class (180–500 tonnes)
Suitable for:
- large silentblocks in massive housing structures
- high interference and long contact lengths
- situations in which maximum frame and guidance stiffness is required
The correct press class is determined by assembly condition and force profile — not by pressing force alone.
When is a workshop press not suitable?
A workshop press is not suitable when:
- the rubber is sensitive to deformation that cannot be controlled mechanically
- the interference varies strongly or is unpredictable
- full axial support of the component is not possible
- rotation, dynamic loading or lateral movement is required
- damage to the rubber–metal bond cannot be structurally ruled out
Further navigation within the site
Based on this application, reference can be made to:
- the relevant press classes within the HD programme
- the available standard models
For operations that fall outside these boundary conditions, reference is made to the engineering and custom-built hydraulic press trajectory, where deviating component geometries and assembly conditions can be assessed technically.
Request technical evaluation
When press-fitting silentblocks and rubber–metal components falls within the described technical conditions, a technical evaluation can be requested to position the application within the correct press class.