How to choose a hydraulic hose crimping machine

The crimping machine is the core piece of equipment in a hydraulic hose assembly shop: the quality of every connection depends on it. A wrong choice does not show immediately. An oversized machine takes up space and ties up money, while a machine without reserve fails on the first non-standard order. In this article we describe the selection procedure we use ourselves when specifying equipment for our customers.

1. Start with the hose, not the machine

Selection begins not with the machine but with the hose You intend to crimp. Determine the largest inner diameter and the type of reinforcement: a 1" hose with two braids (2SN) and a 1" hose with four spiral layers (4SH) require forces that differ several times over. It is the combination of diameter and hose construction that defines the class of machine.

2. How radial crimping works — and why it matters for selection

All modern machines use the same principle: a ring of 6–10 die segments closes towards the centre simultaneously, plastically deforming the fitting ferrule on the hose. The force is applied radially and evenly around the circumference, so the joint is axisymmetric, with no weak side.

The technology came to hydraulics in the mid-20th century, when clamp-type connections could no longer withstand the rising pressures of mobile machinery. Radial crimping displaced the alternatives first of all because the deformation is controllable: the crimp diameter is set to hundredths of a millimetre and therefore reproduced in series. Modern CNC machines are direct descendants of this idea — they brought control of diameter and force to full automation.

3. Dies: the main consumable and the main parameter

You buy the machine once, but You will keep buying dies. So look not only at the crimping range but also at the die system:

• Series size (P16, P18, P20, P32, P120…) determines which die sets fit Your head and what You can find on the market. The more common the series, the easier it is to source dies for it.
• Die length (L) must cover the ferrule length of Your fittings; extended sets exist for long ferrules.
• Intermediate (reducing) dies let a large head work with small diameters — essential for universal workshops.
• Non-standard profiles are made to drawings — if You crimp a fitting of Your own design, confirm this option before buying.

4. Power supply and automation: four scenarios

CNC pays off not so much through speed as through repeatability: the operator simply selects a programme, the machine holds the diameter itself, and the cycle log provides the traceability that demanding customers increasingly ask for.

5. Not only hoses: hidden capabilities of the press

A radial press produces a uniform, controlled circumferential force, so its field of application is wider than hose assembly:

• Tube end calibration. After cutting and bending a tube often goes oval. A large press with smooth dies restores the end to a true cylinder before machining or welding — the operation takes seconds.
• Crimping of cable lugs and wire rope ferrules of large cross-sections.
• Assembly of silent blocks and bushings, pressing of rings.
• Crimping of air suspension bellows — dedicated machines with a rotary table are produced for this.

Pre-order checklist

1. Largest hose (diameter + number of braids/spirals) and the outlook for the next 2–3 years.
2. Head opening: will Your flanged fittings and 90° elbows pass through?
3. Die series, availability of intermediate sets and manufacture to drawings.
4. Power supply at the place of use (phases, voltage, compressed air).
5. How You work: one-off repairs or series? For series, take CNC with a cycle counter.
6. Dimensions and weight — will the machine fit Your premises and how will You bring it in?
7. Scope of delivery: basic dies, foot pedal, stand — what is included and what is optional.