The difference, in short
Our hydraulic press is a forming machine, not a hydroforming installation: we do not offer forming by fluid pressure, the process that replaces the punch with liquid under pressure (also called hydro-bulging). What we do is deep drawing with a punch-and-die tool, exactly as on a mechanical press, with the advantage that the force is constant through the stroke and the pressure and speed profile is programmable. The press is 250 t, with a 0.8 × 1.2 m table.
Hydraulic press or mechanical press
| Criterion | Mechanical press | Hydraulic press |
|---|---|---|
| How the force behaves | Peaks near bottom dead centre, varies through the stroke | Constant through the stroke and adjustable |
| Speed | Fast, suited to long runs | Slower, longer cycle |
| Setting the process | Set by the tool and the mechanical adjustment | Pressure and speed profile programmable: less time in tryout |
| Parts it suits | Medium depth, long runs, sensitive piece price | Deep forms, heavy gauge or high-strength material, short runs and pre-series |
| Overload protection | Limited by the mechanical structure | Pressure limit is adjustable, so the tool takes less punishment |
Our means
| Item | Range |
|---|---|
| Hydraulic press | 250 t, table 0.8 m × 1.2 m (800 × 1,200 mm) |
| Maximum draw diameter | Ø250 mm |
| Wall thickness (sensor housings, catalogue) | 0.25 mm to 1.00 mm, most commonly 0.50 mm |
| Materials | Stainless 301, 304, 304 DDQ, 305, 309/310, 316/316L, 430; steel DC01/DC04; brass; copper; aluminium 1100-O, 3003-O, 6061-O |
| Tooling | Designed and built in-house, in the same plant as the presses |
The 0.8 × 1.2 m table sets the maximum die and blank size. Number of steps, pressure profile and tooling are confirmed part by part against the drawing: diameter, depth, material and batch size decide the machine and the route.
Hydrogen absorption and hydrogen embrittlement
Hydrogen is not the “hydro” in hydroforming, but it matters to any formed part that is later pickled, plated or welded. When steel, titanium or similar metals are pickled, electroplated, welded or exposed to high-pressure hydrogen, small hydrogen atoms diffuse into the metal lattice.
- What happens: the absorbed atoms recombine into hydrogen molecules or form hydrides inside the metal, generating large internal stresses.
- What it causes: the material embrittles and micro-cracks appear — hydrogen-induced cracking, or hydrogen embrittlement — often hours or days after the part was made rather than immediately.
- How it is prevented: dehydrogenation baking after plating or pickling, or a change of process route, for example hot forming instead of cold forming. The cycle belongs on the drawing, not on a decision taken on the shop floor.
At Balford, hydrogen-removal annealing is carried out when the drawing specifies it. Production heat treatment is subcontracted and we say so rather than implying the furnace is in our own plant; the forming route and the inspection are in-house.
Frequently asked questions
Do you do hydroforming or fluid-pressure forming?
No. That is a different process, in which fluid under pressure replaces the punch, and it is not part of our programme. Our hydraulic press drives a conventional punch-and-die tool: the forming principle is the same as on a mechanical press.
When is the hydraulic press the right choice?
Deep forms, heavy gauge or high-strength material, runs that are not large, and the tryout stage, where pressure and speed need adjusting more than once. For medium depths in long runs where the piece price matters, a mechanical press is the cheaper route.
Can I get a closed part with no weld seam?
Yes. Deep drawing produces a continuous wall in one piece, with no weld, which is what makes a housing leak-tight and dimensionally stable against a welded body.
How is a drawn part checked?
Dimensional conformance – inside and outside diameter, wall thickness, heights and step positions – is recorded in our own inspection lab, and geometric characteristics such as coaxiality are part of that. Where a formal CMM report is required, the measurement is organised through a partner lab and flagged before the quotation.
Related pages
Written by the Balford technical team, Zhuji, Zhejiang. Last updated 8 October 2026.