METALPET

Which process, for which part

The five above are a menu. Below is the map: which of them your part needs, and why the order matters.

A part of revolution — shaft, bushing, flange
It starts at turning. If it also has off-axis holes, flats or a keyway, the lathes with live tooling do them in the same setup; with a Y-axis, off-axis milling too. Every setup avoided is one positioning error fewer.
A prismatic part, with faces in several directions
It goes to milling. On the five-axis centre, angled faces are clamped once: position is not lost between setups and their deviations do not add up. For simple parts with parallel faces, the three-axis centre is cheaper and just as good.
A hardened part, above roughly 55 HRC
The shape is cut before heat treatment, with an allowance; final dimensions afterwards, by grinding or wire EDM. The wire also cuts sharp internal corners that no cutter can produce — the cutter radius stays in the corner.
Every part, at the start and at the end
Everything begins at sawing, and the length ordered is always greater than the one on the drawing: the sawn end is faced off, and the part needs a section to be held by. Measurement accompanies the whole route, not only its end.

One part, from drawing to delivery

An example, not a reference: the shaft drawn above, in a run of 250 pieces from quenched-and-tempered 42CrMo4, with a keyway and a sealing surface. The input figures are chosen for the example; what the table shows is the order, and what each operation leaves for the next.

Operation What happens What it leaves behind
Sawing The bar is cut to the ordered length, longer than the one on the drawing. An allowance to face off the sawn end, and a section for the chuck to hold.
Stress relief The blank is held at temperature and cooled slowly. The stresses from rolling, released now, no longer move the part between roughing and finishing.
Roughing The bulk of the material comes off, with deep passes and a firm feed. An even allowance of a few tenths, so that finishing cuts the same everywhere.
Finishing The functional dimensions are turned, with live tooling for the keyway. The diameter inside the h7 field and the sealing surface at the required finish, in a single setup.
Measurement The first article is measured in full; the rest is sampled on the agreed characteristics. The first article report before the series, the dimensional protocol with every batch.
Delivery The parts leave with the batch documentation. A 3.1 material certificate, the dimensional protocol, traceability to the heat number.

What is deliberately missing from the table: times and price. Those are worked out on your drawing, not on ours — an example that also gave figures would be a quotation for somebody else’s part.

Does your part fit our park?

Enter a diameter and a length. We will show you which machines can cut it.

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