CNC Machining Case Studies — Real Parts, Real Tolerances

CNC machining case studies

These cnc machining case studies describe six parts we machine regularly — the material, the feature tolerances, the batch size and the lead time. They are written without customer names or project details, because the point is the machining, not the buyer. What carries over from one order to the next is the same floor, the same process and the same paperwork described on our factory and equipment list pages.

Every example below reflects the tolerances we actually state: ISO 2768-m for general dimensions and ±0.01 mm on the features that need it. Where a number is specific, it is a tolerance we hold; where it is not confirmed, we say “reviewed against your drawing.”

The six parts below span turning, milling and threading, so together they show the range one floor covers — from a single close-tolerance feature on a shaft to a long production run of a simple bushing. Each was quoted the same way yours will be: material first, then the tolerances that decide fit, then quantity and lead time.

Stainless steel shaft

Material: stainless steel 303 or 316L. A turned shaft with a bearing seat held to ±0.01 mm and ISO 2768-m on the remaining lengths. Quantities run from the low hundreds to the low thousands per order, with production lead time in the 25–35 day range after a 5–10 day sample. For this kind of part, the concentricity between the seat and the overall length is the feature that decides fit.

Aluminium housing

Material: aluminium 6061 or 7075. A milled enclosure or housing with a locating face and hole pattern inside our 800 × 500 mm milling envelope, precision features held to ±0.01 mm. Batch sizes run from roughly 50 to several thousand, with surface finishing such as anodizing managed through our vetted partner network. Samples in 5–10 days, production in 25–35 days.

Brass fitting

Material: brass. A small fitting or adapter with threads cut to the standard on the drawing, in volumes from a few hundred to tens of thousands — the kind of part Swiss-type or turning equipment suits. Samples in 5–10 days, production in 25–35 days.

Non-standard bolt

Material: carbon or alloy steel, sometimes stainless. A custom bolt to a non-standard length or head form, threaded to metric or inch standards. Close tolerance bolts hold the shank or thread runout to ±0.01 mm where the drawing requires, in batch sizes from hundreds to large production runs. A 5–10 day sample comes first, then production in 25–35 days.

Bushing batch

Material: brass or steel. A high-volume run of bushings with bore and outside diameter held concentric to ±0.01 mm, in quantities from a few thousand upward, with samples in 5–10 days and production in 25–35 days. This is a case where the economics favor one setup carried across a long production run.

Flange

Material: stainless steel or carbon steel. A flange with a flat sealing face and a bolt circle, milled with hole positions held tight so the mating part lines up. Batch sizes in the hundreds, production lead time in the 25–35 day range, with a material certificate and pre-shipment photos — see quality documents.

If one of these parts resembles yours, send the drawing and we will quote it the same way — tolerance first, then price and lead time.