Press-fitting and extracting pins and dowel pins is an axial operation in which interference, alignment, support and force build-up directly determine whether mounting or dismounting can be carried out without structural damage.
Pins and dowel pins can seize significantly due to interference, deformation or corrosion. The pressing operation must therefore proceed fully linearly and reproducibly. A hydraulic workshop press is suitable when the technical boundary conditions demonstrably fall within the working range of the press.
This page describes when press-fitting and extracting pins and dowel pins falls within this application range – and when it does not
When is a hydraulic workshop press suitable?
A hydraulic workshop press is suitable when:
- the pin can be pressed in or extracted fully axially, without rotation or impact loading
- the pressing force is built up gradually and controllably
- the surrounding component can be supported stably, flat and fully
- force introduction takes place exactly centrally on the pin
- the interference fit is predictable and falls within a reproducible force band
When one or more of these conditions cannot be ensured, the operation falls outside the intended application range.
Technical considerations
Pressing force & force build-up
The required pressing force is determined by:
- diameter of pin or dowel pin
- interference (Δd)
- contact length
- material combination
- surface roughness of pin and bore
Important for force build-up:
- force must be built up step by step to avoid peak loading
- any abrupt increase in resistance must be interpreted as indication of galling, corrosion or misalignment
- the force curve must be followed constantly, especially in long fits
With corrosion, micro-anchoring occurs over the full contact length. The pin moves only after the adhesion limit is broken, which can cause a sudden force drop that may trigger damage to surrounding parts.
Interference, alignment & support
A stable pressing operation requires:
- exact axial alignment from the first millimetres of the stroke
- central loading of the pin, without radial component
- full support of the housing or hub to prevent deformation
- avoidance of lateral loading that can pull bores oval or conical
Misalignment of only a few tenths of a millimetre leads to an asymmetrical force profile, causing bores to be locally reworked or to deform. The damage often becomes visible only after disassembly.
Structural requirements for the press
A suitable hydraulic workshop press has:
- a welded steel frame with minimal lateral deflection
- linear stroke guidance that guarantees constant geometry
- pressing tools that centre exactly over the pin or dowel pin
- a flat, stable working table for supporting the surrounding component
- sufficient mass to dampen impact loading and microvibrations
When the frame deflects laterally by more than 0.3–0.5 mm, lateral force components arise that tilt pins and damage bores.
What is often underestimated in practice
- seized pins due to corrosion or plastic deformation
- deviations in interference caused by previous mounting loads
- bore damage from minimal misalignment
- force peaks due to overly rapid operation
- insufficient support of housing or shaft parts
- large variation in dismounting force in seemingly identical components
These factors determine whether the operation can be carried out dimensionally stable and without damage.
Typical operations within this application
- press-fitting dowel pins into shafts, hubs and coupling elements
- extracting retaining pins and dowel pins during rework
- dismounting interference fits in machine parts
- maintenance on mechanical connections
- series mounting and dismounting in workshop environments
This list describes the nature of the operation, not the suitability of a specific model.
Relation to press classes (HD programme)
Classification within the HD programme is determined by:
- diameter
- interference
- contact length
- structural stiffness
- force profile
Light-duty press class (20–60 tonnes)
Suitable for:
- smaller pins and dowel pins
- short fits
- low to medium interference
- components that can be supported linearly with ease
Medium-duty press class (80–160 tonnes)
Suitable for:
- typical pin and dowel pin dimensions
- stable housing and shaft structures
- reproducible force build-up in standard rework and maintenance operations
Heavy-duty press class (180–500 tonnes)
Suitable for:
- larger diameters
- long fits
- high interference
- situations in which maximum frame and guidance stiffness is necessary
The correct press class is determined by force profile and mounting conditions – not by pressing force alone.
When is a workshop press not suitable?
A workshop press is not suitable when:
- the pin is seized due to heavy corrosion or plastic deformation
- rotation, impact loading or thermal techniques are required
- the surrounding component cannot be supported fully and stably
- the interference varies strongly or is unknown
- structural damage to bores or components cannot be 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 applications that fall outside these boundary conditions, reference is made to the engineering and custom-built hydraulic press trajectory, in which non-standard geometries and complex interferences are assessed technically.
Request technical evaluation
When press-fitting or extracting pins and dowel pins falls within the described technical boundary conditions, a technical evaluation can be requested to position the application within the correct press class.