Induction training · Hydraulic cylinder plant
Every cylinder we build starts as plain steel bars and tubes arriving at the gate. Over twenty operations in eight production buildings it becomes a tested, painted cylinder, ready for a customer's excavator, tractor, crane or tipper truck. Press play to follow one cylinder through the whole plant, or click any operation on the route card to jump to it.
Oil pumped into the base-end port pushes the piston and the rod moves out. Oil pumped into the rod-end port pulls it back in. The highlighted parts are the ones being worked on at the current step.
Cold-drawn steel tube that holds the oil. Its bore is finished mirror-smooth for the piston seals.
Closes one end of the tube. The clevis hole pins the cylinder to the machine.
Where the hoses connect. One port extends the rod, the other retracts it.
Induction-hardened, hard-chrome plated steel rod that pushes and pulls the load.
Forged eye friction-welded to the rod end. It connects to the moving part of the machine.
Splits the tube into two oil chambers. Oil pressure on its face creates the force.
Holds the piston on the rod. Torqued, marked and locked so it can never come loose.
Screws into the tube mouth, guides the rod and carries the rod seals.
Piston seal, rod seal, wear rings, O-rings and a wiper that keeps dirt out.
| Stage | What is checked | How |
|---|---|---|
| Incoming | Chemistry, hardness, size, MTC | Spectrometer, hardness tester, vernier |
| Induction hardening | Surface hardness 55–60 HRC, case depth | Rockwell tester, cut sample |
| Grinding | Diameter, roundness, straightness | Micrometer, dial gauge on V-blocks |
| Chrome plating | Layer 20–25 µm, hardness, adhesion | Coating thickness gauge |
| Polishing | Roughness Ra ≤ 0.2 µm | Surface roughness tester |
| Tube bore | Ø80 H8, Ra ≤ 0.4 µm, straightness | Bore gauge, roughness tester |
| Welding | Cracks, porosity, penetration | Visual, dye penetrant, cut-and-etch |
| Machining | Threads, grooves, first-off part | Ring and plug gauges, CMM |
| Assembly | Cleanliness, seal fitment, torque | Patch test, checklist, torque tools |
| Testing | Leaks at 375 bar, drift, smooth stroke | Test bench, test report |
| Paint | Film thickness 60–80 µm, adhesion | DFT gauge, cross-cut test |
The values on this page are for the example job. The drawing and work instruction for your part always set the real limits.
| MTC | Mill Test Certificate: the steel maker's report of chemistry and strength. |
| Heat no. | Batch number of the steel melt, used to trace every part. |
| Route card | Travel document listing each operation; signed off as the job moves. |
| FIFO | First in, first out: use the oldest material in stores first. |
| First-off | The first part of a batch, checked by QC before the rest are made. |
| µm | Micron: a thousandth of a millimetre. A hair is about 70 µm. |
| Ra | Surface roughness. Smaller is smoother. |
| HRC | Rockwell C hardness scale. |
| bar | Pressure unit. 250 bar is about 250 kg pressing on every cm². |
| NCR | Non-conformance report, raised when a part is out of limits. |
| 5S | Sort, set in order, shine, standardise, sustain. |
| Poka-yoke | A mistake-proofing fixture or check that makes errors impossible. |
Building numbers, the site layout and the process values are illustrative. Your unit's layout, work instructions and drawings always come first.