Bolted / Mill-Type Hydraulic Cylinder Design (ISO 6022)

We design heavy-duty bolted, mill-type hydraulic cylinders to the ISO 6022 range and to customer specifications, with full rod buckling and burst pressure calculations for CAT3 and third-party approval. This is the construction for the highest forces and the most demanding duty cycles.

What Is a Bolted / Mill-Type Cylinder?

A bolted or mill-type cylinder holds its end caps to the barrel with high-tensile bolts into flanges or a bolted head, giving an extremely strong, rebuildable cylinder for the toughest applications. ISO 6022 covers the mounting dimensions for this heavier, higher-pressure class of single-rod cylinder.

When to Choose Bolted Construction

Bolted mill-type cylinders are built for heavy industry, presses, steelworks and other high-force, high-pressure duties where robustness and long service life outweigh compactness. For lighter industrial duty a tie-rod (ISO 6020) cylinder or a welded cylinder may be the better choice, and we design all three.

Our Bolted Cylinder Design Service

We model the complete cylinder in SolidWorks Design Premium – barrel, bolted heads, gland, piston, rod, seals and mountings – and produce the manufacturing and general arrangement drawings to build it, with fastener, seal and material selection appropriate to the pressure and duty.

Calculations & Verification

Rod buckling and burst pressure calculations are carried out as standard, and we can prepare full calculation packages for CAT3 checkers and third-party inspectors including ABS, DNV and Lloyd's Register.

Frequently Asked Questions

What is a mill-type hydraulic cylinder?

A mill-type cylinder is a heavy-duty bolted-construction cylinder, built to ISO 6022 mounting dimensions, designed for high pressures and demanding, high-force applications such as presses and heavy industry.

What is the difference between ISO 6020 and ISO 6022 cylinders?

Broadly, ISO 6020 covers the lighter tie-rod cylinder series and ISO 6022 covers the heavier, higher-pressure bolted series. We design to both and will recommend the right class for your working pressure and duty.

Can you produce calculations for CAT3 or third-party approval?

Yes. We provide rod buckling and burst pressure calculations and full calculation packages suitable for CAT3 checkers and third-party inspectors including ABS, DNV and Lloyd's Register.

Talk to us about your project. Contact Yorkshire CAD Services for a no-obligation discussion, or call 01642 668 043.