CNC machining services

Most machined parts in a new product are drawn during design, long before production. A bracket or a motor mount often changes between the demo build and DVT, so the first step is an engineering read of the drawing. Four things decide the cost of a machined part, in roughly this order: the number of setups, the tightest tolerance on the drawing, the material and the finish. Putting the tightest band on every dimension is the most common and most expensive drawing error, and our engineers flag it before you pay.

When a part belongs to a design project, it goes through a DFM review while it is still in CAD. Our engineers look at the features that set the process: deep pockets, thin walls, small internal radii, threads and datums. They ask what each tolerance does. A bore that locates a bearing needs a tight band, and a clearance hole does not. The findings report sorts each finding by when it must be fixed: before the demo build, before EVT or before production.

When you order a part through the portal, engineering review checks your files against the configuration you chose. It confirms whether the declared tolerance band is achievable on the feature, at that length, in that material and finish, and it checks the setups the geometry implies against the setup complexity you declared.

Material choice follows the same logic. The configurator declares eight material families. Parts in PEEK, Ultem, Inconel or other alloys outside those families go through engineering review. You can select titanium online, and every titanium order goes to an engineer for review.

For regulated products, the Shenzhen factory holds ISO 9001, ISO 13485, IATF 16949 and AS9100. Medical device parts are built under ISO 13485, automotive and EV parts under IATF 16949, and aerospace and drone parts under AS9100.

Mostly the number of setups. Each time the part is unclamped, turned and fixtured again, a machinist does the work and the machine waits. A part cut from two directions costs much less than one that needs five. After setups, the tightest tolerance, the material and the cosmetic finish add cost, in that order.

Setup complexity is a declared field with three settings: simple at one or two setups, moderate at three or four, and complex or 5-axis. You declare it, and the review checks it against the model.

The tightest tolerance anywhere on the drawing sets the process for the whole part. Titanium and stainless cut far more slowly than aluminum. A cosmetic surface limits how the part can be held and deburred. A DFM review in design removes a setup for the cost of a CAD edit.

The loosest band that still works. The configurator offers four bands: general ISO 2768, ±0.10 mm, ±0.05 mm, and ±0.02 mm or tighter. The tightest band always routes to engineering review. Tolerance belongs to a feature, so the review answers it against your drawing.

The review asks one question: is this band achievable on this feature, in this material, at this length?

Tolerance every feature that has a function, such as a bearing bore, a sealing face or a locating pin. Leave the rest at the general band. The same part becomes cheaper and no worse.

Start with aluminum 6061: it machines fast, anodizes well and is stiff enough for most structures. Move to 7075 for more strength, stainless 304 or 316 for corrosion, and titanium for strength-to-weight or biocompatibility. Brass suits fine detail; engineering plastic suits electrical isolation and low weight.

Aluminum 7075 is stronger than 6061, but it resists corrosion less well and cannot be welded. Stainless 316 is the better choice near chlorides. Titanium is the slowest of the eight declared families to cut, and most of its cost comes from that machine time.

PEEK and Ultem suit hot or chemically harsh parts; Inconel suits parts near heat. Each goes through engineering review. The CNC machining design guide covers material and 5-axis choices in more depth.