What is a servo press?

A servo press uses servo motors for precise force and position control during forming operations.

How do I calculate servo press tonnage?

Use our free tonnage calculator at servopress.club/tonnage-calculator.html

Servo Press Specifications Explained: What the Numbers Mean

admin

Press specifications can be confusing. Here is what each number actually means and why it matters.

## Nominal Tonnage

The maximum force the press can exert, measured in metric tons or kilonewtons. **Critical:** This is the force available at a specific point in the stroke — typically 6mm or 3mm before BDC for mechanical presses. At higher positions in the stroke, available force is lower.

For servo presses, the tonnage curve is different — some designs can deliver full tonnage throughout a larger portion of the stroke.

## Stroke Length

The total distance the slide travels from TDC to BDC. Longer stroke allows deeper draws and more die space. Typical range: 100mm to 500mm for servo presses.

## Strokes Per Minute (SPM)

Maximum cycle rate. For servo presses, this is the maximum at no-load. Actual production SPM depends on the motion profile and forming requirements. A servo press rated at 60 SPM may only achieve 20 SPM in a deep drawing application.

## Slide Adjustment

The range over which the slide shut height can be adjusted. Larger adjustment range accommodates more die heights without bolster risers.

## Bed Size (Bolster Dimensions)

Left-right x front-back dimensions of the working area. Must be larger than your largest die.

## Throat Depth

Distance from the slide centerline to the frame. Relevant for side-loading operations.

## Motor Power (kW)

For servo presses, this determines the energy available for high-speed or high-force operations. A press with insufficient motor power will fault on overload during demanding applications.

## Slide Parallelism Specification

Factory specification for slide-to-bolster parallelism. Better presses specify 0.01-0.02mm/300mm. This directly affects part quality and tool life.

## Position Repeatability

How consistently the slide returns to the same BDC position stroke after stroke. Servo presses typically achieve ±0.01mm. This is critical for fine blanking and precision forming.

jim_applications

The most misunderstood spec is torque capacity vs force capacity. A servo press might be rated 200 tons but only at a specific slide position (usually 10-15mm above BDC). At higher positions the available force drops because torque is constant but the mechanical advantage changes. Always check the force-stroke curve, not just the peak number.

sarah_mfg_eng

SPM rating is another misleading spec. The rated SPM is usually for a short stroke (like 30mm). On a full stroke deep draw job, actual SPM might be 40-50% of the rated number. When comparing presses, always specify your actual stroke length and ask for SPM at that stroke.