Machined Metal Parts Services

Tolerance and schedule interact: a tight tolerance can add a finishing operation and stretch the date. Milling and turning hold ±0.003 mm (milling) / ±0.002 mm (turning) and grinding holds ±0.002 mm, with Ppk ≥ 1.67 at the initial study on key characteristics, verified on Hexagon CMMs. The planner routes the part once, to the process that holds the tolerance, so the schedule does not slip on rework.

Process	Tolerance	Schedule effect
Milling	±0.003 mm	Standard routing
Turning	±0.002 mm	Standard routing
Grinding	±0.002 mm	Adds a finishing step

A tolerance the shop cannot hold forces a second operation, and a second operation is a second hand-off.

How does the service plan for your volume?

Capacity planning is a two-way street. Share your annual volume and your ramp, and the service reserves capacity so production lead times do not surprise you. If you share the forecast, you get a schedule; if you hide it, you get whatever is left.

Before you commit a forecast, confirm three things:

• Is the reserved capacity a real allocation? Ask how it is protected against other jobs.
• Does the service re-plan against your numbers? A forecast that is filed, not used, helps no one.
• What happens when the date slips? Get the recovery rule in writing before you need it.

What commercial terms should the service state up front?

Term	What to confirm	Our position
MOQ	No hidden minimum	1 piece
Lead time	Set by process steps	~3 / 7 / 30 days
Inspection standard	Which report ships with the parts	CMM report + SPC
Non-conformance	Who pays for a remake	Agreed before the order

Terms stated up front remove the argument from the delivery date. When non-conformance rules are agreed before the order, a remake is a process, not a negotiation, and the schedule recovers faster.

What red flags signal a weak schedule promise?

How does the CNC milling service keep a date short?

Milling is the workhorse for prismatic parts, and its schedule effect comes down to how many axes the job needs. A 3-axis center cuts flat and stepped features in one or two setups; a 4-axis adds indexing so a part with features on several faces does not need re-fixturing; a 5-axis reaches angled faces in one setup that would take a 3-axis several.

Milling service	Best for	Schedule effect
3-axis	Flat, prismatic parts	Fast, one or two setups
4-axis	Features on multiple faces	Cuts refixturing
5-axis	Angled faces, compound geometry	Fewest setups

The service routes the part to the machine that reaches all its features with the fewest setups. Every setup avoided is a day the part keeps moving instead of waiting to be re-clamped.

How does the CNC turning service keep a date short?

Turning handles round parts in one chucking, which is why shafts, pins, and bushings ship fast. A lathe turns the outside, bores the inside, and cuts threads without the part leaving the machine, so concentric features stay concentric and the schedule does not pay for a second setup.

The turning envelope is Ø720 × 1280 mm, which covers long shafts and large diameters without splitting the part across machines. When a round part also needs milled flats or cross-holes, it moves to a mill-turn, still in one setup.

How does mill-turn machining cut setups?

A mill-turn combines turning and milling on one spindle line. A part with a turned body and milled flats or cross-drilled holes runs in a single chucking, which preserves concentricity and removes the hand-off between a lathe and a mill. The schedule saves the setup that would otherwise split the part.

For cross-drilled or off-center features on a round part, mill-turn is the difference between one operation and three. Fewer operations means the part clears the shop faster and the date holds better.

How does grinding fit into the schedule?

Grinding is the finishing step that tight tolerances pull into the schedule. When a surface needs ±0.002 mm or a bore needs a controlled roundness, the part moves from the mill or lathe to a grinder, and that move is an added operation with its own queue.

Grinding type	What it achieves	Schedule effect
Surface grinding	Flat surfaces to ±0.002 mm	Added finishing step
Cylindrical grinding	Round OD to tight tolerance	Added finishing step
Centerless grinding	High-volume round parts	Fast once set up

The schedule rule is the same as elsewhere: only grind what must be ground. A surface that needs a ground finish earns the extra step; one that does not just adds time.

How do you pick the right service for a part?

The right service is the one that reaches all the part's features in the fewest operations. A round part goes to turning; a prismatic part to milling; a part with both to mill-turn; a tight-tolerance surface to grinding. The wrong pick adds setups, and setups are time.

When you send a drawing, the service reads the geometry and routes it accordingly. You do not need to choose the machine — you need to describe the part honestly, and the routing follows. A service that asks which machine you want instead of telling you is letting you guess at its schedule.

How does the service sequence multiple operations?

Sequencing is where the schedule is won or lost. A part that needs milling, then heat treatment, then grinding has a fixed order — you cannot grind before you harden. The service plans that order so each step feeds the next without a gap, and runs what can be parallel in parallel.

The hand-offs between steps are the schedule's weak points, because each hand-off is a queue. A service that sequences the steps and states the total honestly gives you a date that includes every wait. One that quotes each step in isolation is hiding the gaps between them.

How does the service handle finishing and heat treatment together?

The combination of finishing and heat treatment is where schedules get complicated, because the two steps interact. A part that is hardened must be ground after hardening, not before; a part that is anodized must be cleaned and masked. The service orders the steps so each one does not undo the previous.

The discipline is to treat the combined route as one schedule, not two separate promises. When the service states the total for milling plus heat treatment plus grinding plus finishing, the date includes every hand-off and every wait. Ask for the combined date, and you will hear either a real plan or a shrug.

What does the service need to quote an honest date?

To quote an honest date the service needs four things: the drawing, the material grade, the finishing and heat-treatment route, and the quantity. With those four, it can build the operation sequence, count the setups, and name the tier. Without them, it is guessing.

The faster you supply those four, the faster the date comes back, and the more accurate it is. A complete request gets a routing; an incomplete one gets a follow-up question, and every round-trip is a day lost from the calendar.

What this shop actually runs

Capability evidence should come as specifics, not slogans. Behind this guide is a 6,800 m2 plant in Dongguan, China running 100+ CNC machines with 100+ staff. The machine list by category:

• 5-axis machining centres (10+) - Mazak VARIAXIS I-600 (510/910/510 mm travel, 12,000 rpm, 22 kW, 71.6 N·m, 30-tool BT40) and Mazak INTEGREX I-250H S (B-axis 0.0001°, 24 kW, 124 N·m, 38-tool HSK-A63). Meant for compound-angle parts, single-setup multi-face prismatic work, and aerospace fittings where datum transfer loss is unacceptable.
• 3-axis / 4-axis machining centres (50+) - Brother SPEEDIO S500Z2N / S700Z2N (10,000 rpm, 14/21-tool ATC, 0.7 s tool-to-tool, Z-axis 2.2 G) and Mazak VCE-430A L / VCE-570C L (10,000 rpm, 118 N·m, 24-tool ATC). Meant for prismatic parts, plates, brackets, housings.
• Swiss-type turning centres (10+) - Citizen Cincom A20-3F7 (Φ20 mm, 10,000 rpm), TSUGAMI B0206-III / B0205-III (Φ20 mm, 0.1 µm), STAR SR-32JII / SR-32J Type N (Φ32 mm, 8,000 rpm). Meant for long, slender rotational parts at ±0.002 mm.
• CNC turning centres (20+) - HEADMAN T70M/1250 (720 mm swing, 117 mm bore, 3,000 rpm, BMT75 12-station turret). Meant for shafts, bushings, flanges up to ±0.002 mm.
• Wire EDM (5+) - Sodick AQ535L (550/350/300 mm travel, ±20° taper, 800 kg workpiece). Meant for hardened tool steel, internal splines, sharp internal corners that milling cannot reach.
• Inspection: Hexagon CMM + 20+ gauges - Hexagon CMM for coordinate measurement, plus vision system, profilometer, hardness tester, coating thickness gauge, XRF for material verification. The 10:1 rule (gauge 10x more accurate than the band) is applied to every feature.
• Machine highlights - VARIAXIS I-600: one-setup multi-face 5-axis + MAZA-CHECK auto-calibration; INTEGREX I-250H S: DONE-IN-ONE mill-turn, B-axis 0.0001° + Ai thermal shield; SPEEDIO S500Z2N / S700Z2N: Z-axis 2.2 G + 0.7 s ATC; Swiss-type: guide-bush switchable + 0.1 µm resolution.

Tolerance: ±0.003 mm CNC milling / ±0.002 mm CNC turning / ±0.002 mm grinding and wire EDM. Capability: Ppk >= 1.67 initial on key characteristics, Cpk >= 1.33 ongoing.

Certificates: ISO 9001:2015 (116024/A/0001/UK/En), IATF 16949:2016 (131941/A/0001/SM/En, with design clause 8.3 excluded, stated openly) and ISO 14001:2015 (116024/B/0001/UK/En), issued to Dongguan Zhuohang Ltd, registration 91441900MA4UWT6X39, founded 2005.

Where we ship: Austria, Belgium, the Czech Republic, Denmark, France, Germany, Greece, Hungary, Ireland, Italy, the Netherlands, Spain, Sweden and the United Kingdom in Europe; Brazil, Canada, Mexico and the United States in the Americas; China, Israel, Japan, Singapore and Sri Lanka in Asia; Australia and New Zealand in Oceania; and South Africa in Africa — plus other countries and regions worldwide, shipped from our base in Dongguan, China.

Contact: Felipe Iglesias, [email protected], +86 13126536955.

Machined Metal Parts Services — Related Pages

• machined metal parts quality