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A 200-ton servo press is not always a 200-ton servo press. The nameplate rating is just the starting point.
## Rated Tonnage vs Available Tonnage
The rated tonnage is the maximum force at a specific point in the stroke, usually 5-10mm before BDC. At other positions the available force is significantly lower: at 25mm above BDC typically 60-70% of rated, at 50mm above BDC typically 30-40%, at 100mm above BDC typically 15-25%.
For deep drawing where forming force is applied over a long stroke, check the force-stroke curve, not just the nameplate.
## Continuous vs Peak Tonnage
Peak tonnage is the maximum force for a single stroke. Continuous tonnage is the force sustainable at rated SPM without overheating. The continuous rating is often 60-70% of peak. For high-volume production size your press so required forming force is 70% or less of the continuous rating.
## Drive Mechanism Differences
Eccentric drive: force curve follows a sine function, maximum force near BDC. Knuckle joint: force curve is much flatter, better for deep drawing. Direct drive: force is constant throughout the stroke.
## Checking Actual Capacity
Calculate required forming force at each point in the stroke. Overlay on the press force-stroke curve. Verify press force exceeds required force with at least 20% margin at every point. Check energy requirement against motor energy rating.