Industries / Material handling
Large Part Machining for Cranes and Material Handling
Safety critical welded structures, and geometry that runs the length of a girder.
Material handling parts are mostly welded, mostly long, and load rated. That combination puts the emphasis on two things machining alone does not solve: the welding has to be qualified to an execution class, and the geometry has to hold over a span far longer than any single machine setup.
The machined features themselves are usually modest. Mounting pads, pin bores, drive housings, bearing seats. What is not modest is keeping them in position relative to each other along a girder that may be twenty metres long, which is why this sector leans on travelling column machines and on survey equipment rather than on a coordinate measuring machine.
Parts that come through this route
Not an exhaustive list. It is here so you can tell whether your part behaves like these, which is what decides the machine and the sequence.
- Crane girders and end carriagesLong welded box sections with machined wheel and drive mounting faces.
- Slew rings and turntablesLarge diameter bolt circles and bearing seats, vertical lathe work.
- Sheave and hook blocksPin bores and side plates where alignment carries the load path.
- Winch and hoist drumsGrooved drums with end flanges and shaft bores.
- Conveyor drive framesMachined pads and bores that set gearbox and pulley alignment.
- Travel wheel assembliesBearing bores and axle seats, usually in batches rather than one-offs.
Where this work usually goes
Machine classes that suit the sector. Full typical envelopes and part weights are on the machine class reference.
Travelling column mill
Long girders machined along their length, with the part staying put and the column moving.
Vertical turning lathe
Slew rings, turntables and drums.
Horizontal boring mill
Drive housings and pin bores that have to line up across a structure.
Materials
S355 as the workhorse, S690 and similar high strength plate where weight matters, forged carbon and alloy steel for shafts and pins, ductile iron for wheels and sheaves, and bronze bushings in pin joints.
Paperwork this sector expects
- EN 1090 execution classStructural steelwork for lifting equipment is usually declared to an execution class, which drives the welding and inspection regime.
- Welding procedure qualificationTo the relevant standard for the class, with welder qualification records.
- Non-destructive testingOn load bearing welds, scoped to the execution class.
- Geometry records over lengthCamber, straightness and the position of machined features along the girder.
What to put in the RFQ
On top of the envelope, finished weight, material and tolerance that every heavy part needs, this sector wants these as well.
- The EN 1090 execution class or the equivalent your specification calls for
- Camber and straightness requirements, and whether they apply loaded or unloaded
- Which faces are machined and which stay as welded
- Position tolerance between machined features along the full length
- Whether the structure is delivered in sections and assembled on site
- Transport envelope, because a long girder is an oversized load before it is anything else
Have a part like these?
Send the envelope, the finished weight and the sector. We match it with shops that already work to this paperwork. Reply within 24 business hours.