Sourcing hydraulic and pneumatic cylinders from China

Duty by type

Read from the UK Trade Tariff on 25 September 2026, linear acting hydraulic cylinders carried 2% duty on goods from China, other hydraulic power engines and motors 4%, pneumatic cylinders and other pneumatic motors 4%, steam engines 2%, and parts of hydraulic engines, wind turbine blades and other parts 0%. None had an anti-dumping measure.

Hydraulic pumps and valves are in other headings; confirm the commodity code for each item.

Specification

Specify bore, rod diameter, stroke, working and test pressure, mounting style, port threads, seal material and working temperature. Mounting dimensions to a recognised standard, such as the ISO 6020 series for hydraulic cylinders or ISO 15552 for pneumatic cylinders, let a Chinese cylinder replace an existing one.

Ask what the seals are and who makes them, because seal failure is the usual warranty claim.

Machinery safety

Cylinders are usually components built into a machine, so the machine builder's UKCA or CE assessment has to cover them. Ask for pressure test certificates for each batch and material certificates for the barrel and rod.

Worked duty example

Suppose, purely for illustration, you import 1,000 double-acting hydraulic cylinders under 8412 21 80 90. At £85,000 free on board and £4,000 to ship and insure, the customs value is £89,000. Hydraulic cylinders at 2% pay £1,780 of duty; VAT is then worked out on value plus duty, £90,780, giving £18,156. Of the £19,936 paid at import, only the £1,780 of duty stays a cost for a VAT-registered business. The method is set out in how UK import duty and VAT work.

Inspection checklist

Acceptance tests: hydraulic cylinders proof-pressure and leakage tested by the methods of ISO 10100, with internal leakage past the piston measured at rated pressure, mounting dimensions checked against ISO 6020-2 or ISO 6022, and pneumatic cylinders checked against ISO 15552 or ISO 6432 for interchangeability.

Rod and barrel: chrome thickness on rods measured by the magnetic method of ISO 2178, chrome hardness by Vickers microhardness to ISO 6507, rod and bore surface roughness measured with a profilometer against the drawing, and rods salt spray tested to ISO 9227 for the hours in the specification.

Cleanliness and documents: oil from a flushed cylinder analysed for particle contamination against the ISO 4406 code in the specification, ports plugged and threads capped, material certificates of type 3.1 under BS EN 10204 for barrel and rod, and seal kits labelled with the seal maker and compound.

What goes wrong

Cylinders fail at the seals and the rod. Seals of the wrong compound or hardness leak or extrude at working pressure and temperature, rods with thin or porous chrome plating pit and then cut the seals, and barrels honed to a poor finish wear seals quickly. Welds at the base and ports crack under pressure cycling, and dirt left inside from machining wrecks pumps and valves when the cylinder is fitted.

Ask for the proof pressure test at 1.5 times working pressure on each cylinder or an agreed sample, check chrome thickness and hardness on rods, measure bore finish, check seal brand and material against the specification, run a stroke and leak test, and make sure ports are plugged and cylinders are flushed and capped before packing.

Testing and inspection

Pressure-test samples, check leakage and rod surface finish, and measure stroke and mounting points. At inspection, check port threads, plugs and packing to keep dirt out.

Cambridge China Bridge sources hydraulic and pneumatic cylinders and motors, with pressure, mounting and seal questions settled before the order. See how our sourcing service works.