Woodworking Machines > Stair Machines > IWM 4 Piston Hydraulic Stair Cramps

Blue IWM 4 piston hydraulic stair cramp machine on castors with vertical clamp posts and motor unit

Close-up of a blue IWM Soukup hydraulic stair cramp frame with bolted steel sections, inside a workshop

Blue-painted steel hydraulic stair cramp frame with four pistons, bolted cross members and hydraulic hose fittings, in a workshop

IWM 4 piston hydraulic stair cramp machine with blue steel frame and hydraulic unit, positioned on a concrete workshop floor

Eaton motor starter control box with red isolator switch mounted above a hydraulic pump motor assembly on a blue steel frame

IWM 4 Piston Hydraulic Stair Cramps

IWM

A hydraulic cramping frame for workshops producing stairs regularly — four rams close all four corners simultaneously, so glue-ups come out square without manual adjustment between jobs.

Typically chosen by

Joinery shops with a consistent run of stair commissions who need glue-ups to close square without relying on manual cramp adjustment
Workshops where stair widths vary across jobs — particularly those regularly working between 800 mm and 1200 mm
Businesses replacing a manual cramping setup to reduce assembly time and the risk of racking during pressing

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Key specification considerations

Stair Width Range

800 mm – 1200 mm

The frame expands in a single parallel movement, so you are not re-setting individual cramps between jobs of different widths.

Hydraulic Pressure

Approx. 10 tonnes

Frame Length

4.5 m standard, available in 500 mm increments

If your typical stair run exceeds 4.5 m, specify a longer frame at order — extending after delivery is not straightforward.

Electrical Supply

380 / 400 V, 3-phase

Three-phase supply is required; confirm your workshop has this available before ordering.

See full specifications

Specification	Value	Notes
Frame Length	4.5 m standard, available in 500 mm increments	If your typical stair run exceeds 4.5 m, specify a longer frame at order — extending after delivery is not straightforward.
Frame Width (min)	840 mm
Frame Width (max)	1240 mm (expandable by 400 mm from minimum)
Stair Width Capacity	800 mm – 1200 mm
Hydraulic Rams	4 units	Four rams ensure all four corners move simultaneously, which is what keeps the assembly parallel under load rather than pulling one end tighter than the other.
Hydraulic Pressure	Approx. 10 tonnes
Cramping Bars (vertical)	8, spaced at 500 mm centres	500 mm spacing keeps bars clear of typical tread-and-riser positions, giving reasonable access along the stair during assembly.
Clamp Height	400 mm
Controls	Motorised pump with push-button starter; simple lever for open/close
Starter / Lever Position	Left- or right-hand operation (specified at order, no extra charge)	Specify this at order stage to suit your workshop layout — it cannot easily be changed once built.
Frame Construction	Heavy-duty welded frame and side rails, thick-gauge box steel
Cramping Fingers	Reinforced steel
Mobility / Stability	Wheel kit or adjustable feet (specified at order)	Wheels suit workshops where the frame needs to be moved between jobs or stored aside; adjustable feet are preferable if the machine will stay in a fixed position.
Voltage	380 / 400 V, 3-phase	Three-phase supply is required; confirm your workshop has this available before ordering.
Weight	Approx. 500 kg (SC4M)	At 500 kg, floor loading capacity should be checked — particularly relevant in older workshop buildings or on upper floors.
Lead Time	4–6 weeks from order

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Is this the right
machine for you?

Choose the IWM 4 Piston Hydraulic Stair Cramps if...

You are producing stairs regularly and need a repeatable, parallel clamping process rather than hand-setting individual cramps each time
Your stair widths vary between jobs — the adjustable frame handles 800–1200 mm without a manual re-set
You want a machine built to your workshop's handed preference (left or right controls) and your required frame length from the outset
You have three-phase power available and a floor capable of supporting approximately 500 kg

Consider an alternate model if...

Your stair volumes are lower or more occasional — the Pouwels DEF-50 Stair Making Machine may offer a more appropriate level of capability for the output required; talk to us about where the crossover sits
You require a more integrated stair-making solution beyond cramping alone — the US Concepts INC. Specialist Stair Machinery range covers broader stair production processes and may be worth discussing if your workflow demands it
Your workshop runs on single-phase supply only — this machine requires three-phase and there is no single-phase variant available; discuss your supply situation with us before specifying
Your typical stair width falls consistently outside the 800–1200 mm range — discuss your specific dimensions with us before specifying