Quality
Every part is checked against your drawing before shipment. Our 12-person Quality Department runs a five-stage inspection process — from raw-material verification to final approval and packaging.
Stage 1
Raw material receiving: on arrival we visually inspect raw materials for damage, rust or contamination, check the quantity against the purchase order, and store materials in the right conditions to prevent degradation.
Material certification: we verify the supplier's certificate of compliance against the ordered material specifications, and run random sampling with third-party lab verification when the industry or customer requires it.
First article inspection: we machine a sample part (first article) and inspect it against the engineering drawings, specifications and tolerance limits; all results are documented and approved by engineering before production starts.
Stage 2
Setup verification: before production we verify machines, tools and fixtures are set up correctly, and run a trial to confirm the machine produces parts within specification.
Dimensional checks: we use micrometers, calipers and CMM (coordinate measuring machine) and run frequent in-process checks to catch errors early and minimise scrap.
Surface finish inspection: we check surface finish by visual inspection, tactile methods and optical instruments, to meet the specified requirements.
Tool wear monitoring: tools are regularly inspected for dulling, chipping or breakage, with a replacement schedule based on usage and wear.
Stage 3
Final dimensional inspection: a comprehensive final check of all dimensions, including critical features, measured in a controlled environment to minimise temperature and humidity effects.
Geometric tolerances: parallelism, perpendicularity, concentricity and angularity are verified, using specialised fixtures for complex geometries.
Visual inspection: a thorough check for cracks, porosity, burrs or surface imperfections, with magnifiers or microscopes for small features and critical areas.
Functional testing: fit and assembly checks, pressure tests or functional performance tests, so parts work as intended.
Stage 4
Inspection reports: all findings — measurements, test results and any non-conformances — are documented clearly and accurately.
Traceability: records trace each part back to its raw material source, manufacturing process and inspections, using part numbers, serial numbers or batch codes.
Corrective actions: for any quality issue we investigate the root cause, take corrective measures, document them, and verify they work.
Stage 5
Quality sign-off: once all inspections are complete, the quality assurance department signs off, and we check all documentation is complete and accurate before releasing parts for shipment.
Packaging and labelling: parts are packed to prevent damage in shipping (foam, cardboard or wooden crates) and labelled with part number, quantity, quality status and any special handling instructions.
Equipment
Production equipment — 78 machines in total. Inspection equipment: Hexagon CMM (0.0015 mm), 2.5D measuring instrument, Mitutoyo roughness tester, projector, concentricity gauge, micrometers and calipers.
CNC Machining Centres — Domestic — 5–850 mm — ±10–20 μm — 26 units
Swiss-Type Lathes, 5-axis — TSUGAMI (Japan) — 2–32 mm — ±5–10 μm — 12 units
Swiss-Type Lathes, 5-axis — TAKISAWA (Japan) — 2–32 mm — ±5–10 μm — 18 units
CNC Lathes with Turret (turn-mill) — Domestic — 5–300 mm — ±10–20 μm — 6 units
CNC Lathes, tool-feed turn-mill — Domestic — 2–46 mm — ±10–20 μm — 10 units
CNC Lathes, tool-feed with manipulator — Domestic — 2–46 mm — ±10–20 μm — 6 units
CMM — HEXAGON (Sweden) — 0.0015 mm — 1 unit
2.5D measuring instrument — WANHAO (China) — 1 unit
Concentricity gauge — Aiceyi ACE-135 — 1 unit
Roughness tester — MITUTOYO (Japan) — Ra 0.005–16 μm — 1 unit
Projector — MITUTOYO (Japan) — 0–100 mm — 1 unit
Micrometers — MITUTOYO — 0.01 mm — 12 units
Height gauges / height masters — MITUTOYO — 0.001 mm — 5 units
Calipers — MITUTOYO — 0.01 mm — 25 units
Quality
Close-up of inspection work.
CMM — HEXAGON (Sweden) — 0.0015 mm — 1 unit
2.5D measuring instrument — WANHAO (China) — 1 unit. Projector — MITUTOYO (Japan) — 0–100 mm — 1 unit.
2.5D measuring instrument — WANHAO (China) — 1 unit
Concentricity gauge — Aiceyi ACE-135 — 1 unit
Height gauges / height masters — MITUTOYO — 0.001 mm — 5 units
Height gauges / height masters — MITUTOYO — 0.001 mm — 5 units
Contact
Send your drawing to Nika Yan — nika@mulmic.com, +86 189 2946 9968.