What does MSTFAB manufacture?

MSTFAB is the international brand of Guangzhou Maisituo Sheet Metal Manufacturing Co., Ltd. It makes drawing-defined sheet metal parts and empty mechanical enclosure shells for OEM buyers, using laser cutting, CNC bending, welding and mechanical assembly. Surface treatments such as powder coating may be coordinated with external partners depending on the order.

Which materials does MSTFAB work with?

Common options include carbon steel, galvanized steel, stainless steel and aluminum. Grade, thickness, dimensions, critical tolerances, hardware, finish and inspection criteria are specified per project on the approved drawing.

What are the MOQ and lead time for custom sheet metal parts?

There is no single MOQ or lead time that applies to every part. MOQ, price, achievable tolerances, lead time, finishing route and inspection deliverables are confirmed in the project quotation and purchase order after the drawing is reviewed.

Does MSTFAB supply electrical components or certified finished equipment?

No. The normal supply scope is fabricated metalwork and empty mechanical housings. Electrical components, wiring, software, system integration and final equipment certification remain with the buyer unless a written quotation or contract explicitly includes them.

How do I request a quote?

Send STEP, STP, DXF, DWG or PDF files with the drawing revision, material and thickness, quantity, critical dimensions, hardware, finish, inspection needs and delivery destination through the RFQ page at https://mstfab.com/contact/.

Sheet Metal Supplier Audit Evidence Checklist

1:36 am
1:36 am

What physical evidence should auditors evaluate during a sheet metal supplier factory audit?

During an on-site sheet metal supplier audit, quality auditors must evaluate physical objective evidence across five key operational domains: (1) raw material heat-lot traceability and mill test report (MTR) binding, (2) preventive maintenance and calibration logs on CNC lasers, press brakes, and CMMs, (3) shop-floor revision governance (no obsolete paper drawings or unpurged CAM programs), (4) automated error-proofing (poke-yoke) and in-process SPC monitoring, and (5) chemical titration logs and environmental salt-spray certifications for surface finishing lines.

Walking through a potential sheet metal vendor’s facility with a superficial checklist does not protect an OEM from catastrophic supply chain failures. Sales representatives will guide auditors through clean executive conference rooms and showcase shiny machinery. An effective technical auditor moves past the presentation slides to inspect tool cribs, scrap bins, backgauge encoders, and calibration stickers. Rigorous physical evidence audits separate certified precision fabricators from risky job shops.

Quality auditor verifying ISO 9001 certification and management review minutes — Auditors cross-referencing ISO 9001:2015 certification scopes, management review minutes, and active customer NCR logs.

The 5 Pillars of On-Site Sheet Metal Supplier Audits

1. Raw Material Receiving & Traceability

Auditors must inspect the raw coil and sheet warehouse. Look for color-coded mill tags, physical heat-lot numbers stamped on sheets, and barcode travelers. Can the warehouse manager pull the certified Mill Test Report (MTR) for a randomly selected aluminum coil within 3 minutes? If not, traceability fails.

Quality auditor auditing color-coded coil stock and mill test report heat lot traceability — Verifying physical color-coding and mill certificate heat-lot binding in raw material storage racks.

2. CNC Laser & Press Brake Calibration

Check the physical machines on the floor: Are laser optics and nozzle centerlines checked daily? Are press brake hydraulic crowning systems and backgauge linear scales calibrated annually by certified metrology technicians? Inspect the physical calibration stickers on all digital calipers, height gauges, and micrometers.

Quality engineer inspecting calibration records and probe calibration on a CMM machine — Auditing CMM calibration logs, ruby probe sphere qualification, and temperature-controlled metrology lab records.

3. Tooling Control & 5S Organization

Examine the press brake tooling crib. Are precision-ground punches and dies stored in organized, foam-lined drawers with marked tip radii (e.g., 0.8 mm, 1.5 mm, 3.0 mm)? Or are tooling segments thrown loose into wooden crates where nicked surfaces can damage production flanges?

Visual inspection of clean organized 5S sheet metal workshop with designated tooling racks — Visual 5S shop floor organization with clearly marked walkways, tool shadow boards, and quarantined WIP staging zones.

On-Site Sheet Metal Supplier Audit Evidence Matrix

The table below provides a comprehensive scoring checklist for auditing precision sheet metal fabrication facilities:

Audit Category	Key Process Characteristic	Mandatory Physical Evidence Required	Red Flag Finding (Immediate Deduct)	Passing Weight
1. Quality Management System	ISO 9001 / IATF 16949 governance	Active registrar certificate, internal audit records, closed NCR log	Expired certification or unclosed audit non-conformances	15%
2. Raw Material & Traceability	Heat lot binding, MTRs, RoHS compliance	MTR matched to physical coil barcode; Positive Material Identification (XRF)	Unlabelled coils or missing mill test certificates	20%
3. Laser & Press Brake Machinery	Equipment capability, backgauge accuracy	Preventive maintenance logs; annual interferometer calibration certs	No scheduled maintenance logs; visible hydraulic leaks	20%
4. Inspection & Metrology Lab	CMM, optical comparator, gauge calibration	Temperature-controlled lab (20±2° C); traceable calibration stickers	Expired gauge stickers; uncalibrated floor calipers	25%
5. Finishing & Chemical Control	Pre-treatment titration, cure profile, adhesion	Daily tank titration logs; oven datalogger curves; ASTM D3359 cross-hatch	No temperature datalogger; unmonitored wash tanks	20%

Printed on-site supplier audit evidence checklist template on an inspection desk — MSTFAB’s comprehensive on-site supplier audit checklist guides quality auditors through evidence-based factory reviews.

Audit-Ready Sheet Metal Manufacturing With MSTFAB

MSTFAB welcomes customer audits. We maintain complete ISO 9001:2015 certification, fully digital material traceability, automated CMM quality gating, and state-of-the-art powder coating lines with daily titration logging. Contact our engineering team today to schedule an on-site factory audit or request our comprehensive quality audit package.

Request Quality Audit Package →