Down-Stroke vs Up-Stroke Forging Screw Press Explained

Screw presses come in two stroke directions, and the choice isn't cosmetic, it changes how force flows through the machine and which parts it forges best. If you're specifying a forging screw press, here's what you need to know.

How a screw press delivers force

In every screw press, a flywheel stores energy and a large screw converts that spinning energy into a forging blow. The energy is adjustable, so you control the blow precisely. What differs between machines is the direction of that blow and where the force lands.

Down-stroke: the traditional configuration

In a down-stroke press, the ram drives downward onto the work, and the forging force is carried through the machine frame.

Strengths: proven, versatile, and well understood. Handles hot forging, cold coining, stamping, embossing, and sizing across ferrous and non-ferrous metals.

Best for: general-purpose forging shops with a varied part mix.

Birson down-stroke friction screw presses: 50-800 tons.

Up-stroke (Vincent type): force taken by the ram

In an up-stroke press, the blow travels upward. The clever part: the forging forces don't act on the machine frame, they're sustained by the ram itself. The screw nut sits in the top cross-head of a frame-type ram, and an ejector at the lower ram helps part removal.

Strengths: because the frame is relieved of forging load, the design suits high-volume, repetitive forging.

Best for: bolt heads, nuts, rivets, motor parts, axle half-shafts, engine valves, and non-ferrous forgings.

Birson up-stroke forging screw presses: 50-1000 tons.

Which should you choose?

If you... — Choose

Run a varied, general forging mix — Down-stroke

Forge fasteners or repetitive parts at volume — Up-stroke

Prioritise frame longevity under heavy repeat blows — Up-stroke

Want the most widely-serviced, familiar setup — Down-stroke

Bottom line

Down-stroke for versatility; up-stroke for high-volume fastener and component forging where you want forging force off the frame. Match the stroke to your part mix and volume, not just the price tag.

Birson Forgings builds both down-stroke (50-800 t) and up-stroke (50-1000 t) forging screw presses. Send us your part and volume and we'll spec the right press.