Zhuohang Precision Machining FactoryCNC Precision Machining

What Tolerance Can CNC Precision Machining Hold

What Tolerance Can CNC Precision Machining Hold — A direct answer to What Tolerance Can Cnc Precision Machining Hold — written for you deciding whether this process fits. Tolerances: ±0.003 mm milling, ±0.002 mm turning — ISO 9001 / IATF 16949 verified.

A direct answer to What Tolerance Can Cnc Precision Machining Hold — written for you deciding whether this process fits the part,.

In brief
  • Exports to 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 — based in China, serving customers worldwide.
  • Dongguan Zhuohang Ltd (Registration No. 91441900MA4UWT6X39), operating as Zhuohang Precision Machining Factory, established 2005.
  • A subtractive process: the finished part is the model minus everything the cutter removed.
  • The real cost is fixed during the manufacturability review, before the first chip.
  • No minimum order — prototype and production run on the same machines.

What happens between drawing and finished part

The sequence is quoting and manufacturability review, programming and offline verification, fixturing, roughing, finishing, inspection, and first-article reporting. Every step can go wrong in its own way, and the costly failures sit at the start and the end.

Cutting is usually the shortest part of the calendar time. Queue position, fixture design, and inspection documentation account for most of the lead, which is why asking for the first-article date and the repeat date separately gives a truer picture than a single lead-time number.

The cost structure of CNC precision machining

Cost is driven by setup time amortised over quantity, cycle time, material and tooling, inspection labour, and the risk premium on the tolerance. On a prototype the setup dominates; on a production run the cycle time does. That is why a per-part price without a quantity is not a price.

The driver buyers most often underestimate is inspection. A drawing that calls out twenty dimensions has a different inspection cost from one that calls out five, and a first-article report has to be authored, not assumed.

Failure modes, and where they are caught

The failures that cost money are not crashes, they are the quiet ones: a tolerance held on the machine but lost in a later operation, a revision built from a superseded drawing, and a surface finish callout that meant something different in another standard.

Each has a cheap control. Datum structure is reviewed at quote stage; the revision is confirmed in writing on the order acknowledgement; the drawing standard is confirmed when the files arrive. None of these controls cost anything, which is what makes their absence inexcusable.

How to verify a CNC precision machining supplier

Finished slender brass (C360) component presented for inspection.

These four checks cost nothing and can be run before any commitment.

  • Can they name the registration number? Ours is 91441900MA4UWT6X39, check it in the National Enterprise Credit Information Publicity System.
  • Do they name machine families and counts? A manufacturer lists models; a reseller recycles stock photos.
  • Are the certificate numbers verifiable? Real ISO/IATF certificates carry numbers you can confirm with the registrar.
  • Can you walk the floor? On-site and video audits are welcome at the Dongguan address.

What design decisions move the cost on CNC precision machining?

Three design decisions drive most of the cost on a machined part: internal corner radii matched to a real cutter diameter, cavity depth kept within about four times the tool diameter, and a general tolerance on every feature that does not mate. Each one changes the tool that can be used, and the tool determines how much material can be removed per minute, which is why these matter more than any process selection.

This belongs in the quote discussion, not the first-article review, because the changes are usually trivial on the drawing and significant on the machine.

What is on the floor, by machine family?

Capacity is depth, not a headline machine. The table below is the routing map: each family has a lane, and the depth in each lane is what keeps a part out of someone else's queue.

Machine familyCountRepresentative modelsRole in the schedule
3-axis vertical machining50+ centresBrother SPEEDIO S500Z2N / S700Z2NPrismatic work at the lowest cost per part
4-axis machining20+ centresMazak VCE-430AL / VCE-570CLIndexed multi-face parts without re-fixturing
5-axis machining20+ centresMazak VARIAXIS i seriesSingle-setup complex geometry
5-axis mill-turn—Mazak INTEGREX i-H seriesTurned and milled features in one clamping
CNC turning / mill-turn25+ lathesMazak QT-COMPACT 200MSY LRound parts, live tooling
Swiss-type turning—Citizen Cincom A20 / Star SR-32JII / Tsugami B0205Long, slender parts at high L/D ratios
Precision grinding7+ grinders—Final tolerance on bearing seats and roundness-critical faces
Wire EDM—SodickSharp internal corners and hardened material

What to read out of this list: a part does not wait behind a single machine. The spare capacity in that family is what lets work move to another lane rather than sit in a queue, and it is what makes a prototype ramp to production on the same floor.

What is the certification position?

ISO 9001:2015, IATF 16949:2016 (excluding clause 8.3 product design), and ISO 14001:2015 — each with a certificate number verifiable with the registrar.

What happens between drawing and finished part

The sequence is quoting and manufacturability review, then programming and offline verification, then fixturing, then roughing, then finishing, then inspection and first-article reporting. Every step can go wrong in its own way, and the costly failures sit at the start and the end.

The manufacturability review is where cost is actually decided. A pocket depth reduced by a few millimetres, or an internal corner radius opened from 1 mm to 3 mm, can cut cycle time more than any change of machine, because it changes the tool that can be used, and a stiffer tool removes more material per minute.

What tolerance can be held, and how is it verified?

Milling and turning hold ±0.003 mm (milling) / ±0.002 mm (turning); precision grinding and wire EDM hold ±0.002 mm. A tolerance is only worth as much as the instrument that verifies it, so the floor runs 20+ inspection instruments alongside the machines — CMM for dimensional and true position, vision and profile instruments for surface and geometry, hardness testers and coating gauges for heat treatment and plating, and XRF for incoming material composition against the mill certificate.

The rule that matters on a drawing is that a tolerance is held by the process, not by the machine. Where a feature is tight, the finishing pass is separated from roughing, the part is allowed to stabilise, and the measurement is taken at a controlled temperature — a part measured warm is not the part the customer receives.

Which entity is responsible for the work?

Dongguan Zhuohang Ltd (Registration No. 91441900MA4UWT6X39, established 2005).

Tolerance bands on CNC precision — what is realistic, what costs extra

The tolerance a CNC precision part holds is a band that depends on the feature, material, and measurement. The five bands: rough (±0.1 mm baseline), standard (±0.05 mm baseline), tight (±0.01 mm, 2-3× baseline), precision (±0.003 mm milling / ±0.002 mm turning, 4-6× baseline), ultra (±0.002 mm and tighter, 10×+ baseline, requires grinding or wire EDM). The precision band is what this factory holds standard; it requires a machine with thermal stability (Mazak VARIAXIS I-600, INTEGREX I-250H S, TSUGAMI B0206-III, STAR SR-32J Type N, Citizen Cincom A20-3F7), a sharp tool, a stable fixture, and a Hexagon CMM with 10:1. The 10:1 measurement rule (ANSI B89): a ±0.003 mm feature requires a gauge at ±0.0003 mm; a ±0.01 mm requires ±0.001 mm; a ±0.05 mm requires ±5 µm. The Ppk/Cpk index: Ppk ≥1.67 on critical features, Cpk ≥1.33 in production.

The shop: Dongguan Zhuohang Ltd (USCC 91441900MA4UWT6X39, established 2005, 6,800 sqm floor, 100+ staff, 100+ machines including Mazak VARIAXIS I-600 5-axis, INTEGREX I-250H S mill-turn, TSUGAMI B0206-III / B0205-III, STAR SR-32JII / SR-32J Type N, Citizen Cincom A20-3F7 Swiss-types, Hexagon CMM with 10:1 measurement-to-tolerance per ANSI B89, temperature-controlled inspection room at 20 ±1 °C, ISO 9001:2015 116024/A/0001/UK/En, IATF 16949:2016 131941/A/0001/SM/En design clause 8.3 excluded, ISO 14001:2015 116024/B/0001/UK/En). Tolerance: ±0.003 mm milling, ±0.002 mm turning, ±0.002 mm grinding, Ppk ≥1.67, Cpk ≥1.33. Contact: Felipe Iglesias, +86 13126536955, [email protected], PT/EN/FR/ES/ZH/JP.

Tolerance band selection — where to tighten, where to leave standard

The tolerance band selection on a CNC precision part is the decision that decides whether the part costs $50 or $500. The rule: tighten only the functional features (mating, sealing, locating), leave the structural features at standard (±0.05 mm or wider per ISO 2768 medium). The functional features are typically 10-30 percent of the part's dimensions; tightening all dimensions to ±0.003 mm pays 5-10× on inspection for no value on the 70-90 percent that does not need it. The functional feature matrix: mating surfaces (the bore that fits a bearing holds ±0.003 mm on diameter and ±5 µm on cylindricity); sealing surfaces (the face that holds pressure holds 0.025 mm flatness and Ra 0.8 µm); locating features (the dowel pin hole holds ±0.003 mm on position); thread features (the tapped hole holds 6H per ISO 6H); gear features (the pitch holds ±5 µm).

The shop: Dongguan Zhuohang Ltd (USCC 91441900MA4UWT6X39, established 2005, 6,800 sqm floor, 100+ staff, 100+ machines, Mazak VARIAXIS I-600, INTEGREX I-250H S, TSUGAMI B0206-III, STAR SR-32J Type N, Citizen Cincom A20-3F7, Hexagon CMM with 10:1, 20 ±1 °C, ISO 9001:2015 116024/A/0001/UK/En, IATF 16949:2016 131941/A/0001/SM/En, ISO 14001:2015 116024/B/0001/UK/En). Tolerance: ±0.003 mm milling, ±0.002 mm turning, Ppk ≥1.67, Cpk ≥1.33. Contact: Felipe Iglesias, +86 13126536955, [email protected], PT/EN/FR/ES/ZH/JP.

Tolerance band selection — where to tighten, where to leave standard

The tolerance band selection on a CNC precision part is the decision that decides whether the part costs $50 or $500. The rule: tighten only the functional features (mating, sealing, locating), leave the structural features at standard (±0.05 mm or wider per ISO 2768 medium). The functional features are typically 10-30 percent of the part's dimensions; tightening all dimensions to ±0.003 mm pays 5-10× on inspection for no value on the 70-90 percent that does not need it. The functional feature matrix: mating surfaces (the bore that fits a bearing holds ±0.003 mm on diameter and ±5 µm on cylindricity); sealing surfaces (the face that holds pressure holds 0.025 mm flatness and Ra 0.8 µm); locating features (the dowel pin hole holds ±0.003 mm on position).

The shop: Dongguan Zhuohang Ltd (USCC 91441900MA4UWT6X39, established 2005, 6,800 sqm, 100+ staff, 100+ machines, Mazak VARIAXIS I-600, INTEGREX I-250H S, TSUGAMI B0206-III, STAR SR-32J Type N, Citizen Cincom A20-3F7, Hexagon CMM 10:1, 20 ±1 °C, ISO 9001:2015 116024/A/0001/UK/En, IATF 16949:2016 131941/A/0001/SM/En, ISO 14001:2015 116024/B/0001/UK/En). Tolerance ±0.003 mm milling, ±0.002 mm turning, Ppk ≥1.67, Cpk ≥1.33. Felipe Iglesias +86 13126536955 [email protected] PT/EN/FR/ES/ZH/JP.

What this shop actually runs

If you ask for capability evidence, you deserve a specific answer. This facility operates 100+ CNC machines across 6,800 m2 in Dongguan, China, staffed by 100+ people. The machines, listed 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). Intended 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). Intended 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). Intended 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). Intended for shafts, bushings, flanges up to ±0.002 mm.
  • Wire EDM (5+) - Sodick AQ535L (550/350/300 mm travel, ±20° taper, 800 kg workpiece). Intended 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 bands: ±0.003 mm milled, ±0.002 mm turned, ±0.002 mm ground or wire-cut. Capability indices: Ppk >= 1.67 at the initial study; Cpk >= 1.33 ongoing in production.

Certifications: ISO 9001:2015 (116024/A/0001/UK/En) · IATF 16949:2016 (131941/A/0001/SM/En, design clause 8.3 excluded) · ISO 14001:2015 (116024/B/0001/UK/En), held by Dongguan Zhuohang Ltd (USCC 91441900MA4UWT6X39, since 2005).

Service area: we supply 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, with worldwide delivery from China.

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

Get a quote with the cost drivers named

Send your drawing to [email protected] or call +86 13126536955. We will tell you which tolerance or setup is driving the number, not just the number.

Frequently Asked Questions

Which markets do you export to?

In short, 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. Our service area also spans Europe, the Americas, Asia, Oceania and Africa — based in China, we serve customers worldwide.

What happens if the first article does not conform?

In short, The nonconformance is documented and the corrective action is agreed before any further parts are made. Whether the replacement cost sits with the plant or the customer depends on where the deviation came from, which is why the revision and the drawing standard are confirmed in writing at the start.

How long does cnc precision machining take?

Lead time is driven less by cutting time than by queue position, fixture design, and inspection. A part that needs a purpose-built fixture has a longer first-article lead and a much shorter repeat lead, which is worth asking about separately.

What is the difference between a prototype build and a production build here?

Usually only quantity and scheduling. Both run on the same machines and the same process, which is what makes a later ramp a scheduling change rather than a re-qualification.

What is the difference between cnc precision machining and similar process?

The practical difference is usually the number of setups and the resulting tolerance stack. Fewer setups means fewer datum transfers, and that is what determines whether a geometric relationship holds.

Can I audit the factory before placing an order?

Yes. On-site visits and video audits are welcome at No. 8, Shuibian Songyuan Road, Hengli Town, Dongguan, Guangdong, China 523470.

Do you sign NDAs before reviewing drawings?

Yes. Sign an NDA before files are exchanged; drawings are kept in the quoting system, not circulated by email.

Standards referenced on this page

  • ASTM A582/A582M-12 — Standard Specification for Free-Machining Stainless Steel Bars
  • ASTM B211/B211M-19 — Standard Specification for Aluminum-Alloy Rolled or Cold Finished Bar, Rod, and Wire
  • ISO 9001 — Quality management systems — Requirements