What are HYDAC’s optimal production capabilities?

Optimal Manufacturing Parameters

  • Bore diameters from 4” to 9”
    ~   Stroke up to 300”
  • Bore diameters from 10” to 20”
    ~   Stroke up to 130”
  • Pressure up to 6,000psi.

Capable, but must consult factory

  • Bore diameters under 4”
  • Bore diameters 10” or larger that exceed 130” stroke
  • Bore diameters greater than 20”
  • Pressures 6,000psi to 10,000psi

Equipment Capabilities

  • Mazak CNC lathe w/ live tooling
  • Mori Sieki NH5500 Vertical Mill w/ pallet changer
  • Haas VF11 Vertical Mill
  • Mori Sieki NL3000 CNC Lathe

What types of cylinders can HYDAC produce?

Welded Type Construction

  • Most cost effective for basic cylinder requirements
  • Welded base plate and threaded head gland

Mill Type Construction

  • Heavy Duty
  • Demanding applications
  • Bolt on head gland and base

Hybrid Type Construction

  • Welded base and bolt on head gland
  • Economic solution to mill type


  • Uniquely design motion control solutions
  • High pressures, large bore, special materials, custom mounting
  • Steering cylinders
  • Linear transducer, proximity switch, and various other type of position sensing
  • Valve integration
  • Dampening
  • Heavy duty porting

Tie Rod Construction

  • We will consider them on a case by case basis.

What type of mounting options are available?

Lug / Clevis (Ears)

  • More customizable due to base material (often machined plate steel).
  • Can be fitted to include bushings, spherical bearing, and/or grease fittings.

Pineye (Crosstube)

  • Cost effective and simple design.
  • Manufactured from tube or bar.
  • Can be fitted to include bushings and/or grease fittings.
  • Common in trailer


  • Allows cylinder to pivot in desired location.
  • Can improve buckling safety factors depending on placement location on the cylinder.

Flange (Head, Mid-Body, & Base)

  • Rigid and improves buckling safety factors depending on location.
  • Often used in mill/hybrid construction type cylinders.
  • Common in press applications.

Additional Mounting Types

  • Threaded rod end
  • Ball mount
  • Rod collar
  • Drill & Tap Mount
  • Foot mounts
  • And many more…

What are the typical materials used in cylinders?

Commonly Used Materials

  • Tube
    ~   1026DOM/ST52.3 DOM
    ~   Readily available and cost effective
  • Rod
    ~   1045CD Chrome Plated
    ~   Readily available and cost effective
  • Head Gland & Piston
    ~   Ductile Iron
    ~   Material composition provides better lubricity.
    ~   Ease of machining.
  • Base Plate
    ~   1018, 1045, & A36
    ~   Readily available and cost effective
  • Mounts
    ~   A516-70, A36

Special Materials

  • Tube
    ~   4140 Honed Tube
    ~   316SS Honed Tube
  • Rod/Bar
    ~   1045 Induction Hardened, Chrome Plated
    ~   4140 Chrome Plated
    ~   316SS Chrome Plated
    ~   17-4PH 1150 Chrome Plated
    ~   Bronze (C954)
  • Plate Steel
    ~   A514 (T1)
    ~   A572-50
  • Other material available. Cost and lead time will be a factor.

Special Rod Coatings

  • Heavy Chrome (.001”min.)
    ~   Nickel/Chrome
    ~   Extra protective properties compared to heavy chrome.
    ~   Applicable for marine applications primarily.
  • Nitro Carburized
    ~   Surface finish is extremely hard, eco friendly, and excellent performance.
    ~   Applicable for applications with corrosive chemicals involved.
    ~   Used in mining extensively.
  • Plasma
    ~   Designed to withstand harsh environments and vigorous demands.
    ~   Popular in offshore and oil/gas applications.

What additional functions can we incorporate into our cylinders?

Additional Functions

  • Electronics
    ~   LVDT Sensors

    • (A) Rod Style, Internal
    • (B) Piston Magnet, External

    ~   Proximity Position Sensor

    • (C) Balluff Shown

    ~   Pressure Transducers

  • Manifolds w/ Valves
    ~   Counter Balance Valve
    ~   Check valves
  • Test Fittings
  • Cylinder cushioning.
    ~   Adjustable & Non-Adjustable

What are some common causes of cylinder failures?

Seal Failures
This is the most common reason for cylinder failures.
Types of Failures:

  • Abrasion
  • Extrusion
  • Explosive Decompression
  • Pressure Trapping
  • Contamination
  • Heat Damage
  • Flex Fatigue
  • Side Loading
  • Dry Running
  • Over Pressurization

Side Loading

  • Side loading is caused from the cylinder being misaligned which creates an unusual force on the piston rod.
  • The longer the cylinder stroke and the further the rod extends along its stroke, the higher potential for side loading and column bending.
    In extreme cases, the rod can be bent.


  • Alignment
  • Guiding the rod.
  • Mounting change.
  • Larger rod
  • Stop tube

Contaminated Fluid

Abrasive particles in the contaminated fluid can bring severe damage to the piston and rod surfaces.

Additonal causes of failure

  • Seal related.
    ~   Dieseling
    ~   Swelling
    ~   Hydrolysis
  • Welding failures.
  • Over-pressurization
  • Temperatures above or below the design capability.

What needs to be considered in order to avoid a cylinder failure?


  • What is actually being done with the cylinder?
  • Will the cylinder need load holding valves?
  • What is the cylinder stroke?
  • What is the cylinder speed?
  • Are there any side loads present?
  • What type of media is being used?
  • Does the cylinder require cushions?
  • What temperatures ranges is the cylinder being subjected to?