EQUIPMENT · September 21, 2026 · 7 MIN READ

HKM3 Press Specifications Decoded: Which Parameter Limits Which Part Feature

An HKM3 press datasheet lists eight parameters that matter to a die designer: nominal tonnage, stroke, strokes per minute, shut height, ram adjustment, table size, ejection stroke and motor power. Each one constrains a specific part feature — tonnage limits projected area, shut height limits die stack height, table size limits die footprint — so a part can be unmakeable on a press that looks oversized on tonnage alone.

WHERE THIS APPLIES AT FORGEPRESS CHINA

ForgePress China matches the HKM3 model to the die layout rather than to tonnage alone, and returns the layout with the quotation. Capacity: HKM3 hot-die forging line 1,000–5,000 t, part weight 0.1–500 kg, maximum envelope 1,200 × 800 mm, as-forged to ISO 8062 class C with critical dimensions machined to ±0.2 mm, process control to ISO 9001, first article 4–8 weeks from die design release.

KEY NUMBERS

Nominal tonnage 1,000–5,000 t across the HKM3 range; usable force at the working point is typically 60–80 % of nameplate.
Die stack height is capped by shut height plus ram adjustment; a 100 mm adjustment buys 100 mm of extra die height.
Table size limits die footprint, and a die must sit at least 50 mm inside the table edge for clamping.
Ejection stroke on models above 600 t is 100 mm, which sets the maximum wall depth that can be ejected without a knock-out.

The eight parameters and what each one actually constrains

Parameter	Constrains	What happens if you exceed it
Nominal tonnage	Projected area × flow stress × K	Short fill, overloading, frame fatigue
Stroke length	Maximum part depth per blow	Part cannot be formed in one hit; needs more stages
Strokes per minute	Output rate and die cooling time	Die overheats, lubrication burns off
Shut height + ram adjustment	Die stack height	Die will not fit; requires a shorter die base
Table size	Die footprint and clamping	Die overhangs; clamping unsafe; table deflects
Ejection stroke	Wall depth that can be ejected	Part sticks; manual extraction; galling
Blanking / cushion force	Trim and draw operations	Trimming leaves tear-off instead of clean shear
Motor power	Continuous duty at high stroke rate	Thermal trip; reduced speed in practice

General behaviour of mechanical forging presses in the 1,000–5,000 t class. Always confirm against the specific model datasheet.

Worked example: why a 2,500 t press can still be the wrong press

Take a flanged hub, 4.2 kg, 42CrMo, projected area with flash 14,800 mm², web 14 mm. Flow stress at 1,000 °C ≈ 120 MPa, flash ratio 1.4 so K ≈ 4.0. Required force = 4.0 × 120 × 14,800 = 7.1 MN ≈ 725 t. A 1,000 t press has ample tonnage.

But the part is 95 mm deep, and the press has a 160 mm stroke with a die stack that already uses most of the shut height. The impression cannot be cut deep enough, so the part needs a blocker stage — which adds a second impression, increases die footprint beyond the table, and pushes the die height past the shut height. The 1,000 t press is now the wrong press, not because of force but because of geometry.

This is why a press quotation should always be accompanied by a die layout drawing. Force is the easy part.

Reading the table size against your die layout

A die must sit inside the table with at least 50 mm of margin on every side for clamps and for the table T-slots. A 900 × 700 mm table therefore accepts a die up to about 800 × 600 mm, and a two-cavity layout for a 4 kg part often needs more than that.

Overhanging a die beyond the table edge is not a small infringement. It puts the clamping bolts in bending instead of shear, and it loads the frame asymmetrically, which shows up as uneven flash wear within a few thousand parts.

Specification checklist for a press enquiry

Part drawing with projected area, depth, web thickness and material grade.
Required output in pieces per hour, and the number of shifts per day.
Die layout concept, even a sketch, to check table size and shut height.
Tolerance and inspection requirements, because they decide whether a coining stage is needed.
Utilities available on site: power, water for cooling, compressed air, foundation depth.

Frequently asked questions

Which HKM3 model suits a 1–2 kg forging?

Usually the 1,000 t or 1,600 t model, but the decision is set by projected area rather than mass. A 1.5 kg part with 8,000 mm² projected area needs roughly 550–700 t of force; a 1.5 kg thin-walled part with 14,000 mm² projected area needs 1,300–1,600 t.

What is shut height and why does it matter?

Shut height is the clear distance between the ram face and the bolster at bottom dead centre with the ram adjustment fully retracted. Together with ram adjustment it caps the total die stack height, so it decides whether your die fits at all — independent of whether the press has enough tonnage.

Can ejection stroke be increased later?

Rarely. Ejection stroke is set by the ram and ejector rod geometry inside the frame, so increasing it means rebuilding the ram assembly. Specify the ejection requirement from the part drawing at the enquiry stage.