Quality Control Based on Inspection and Traceability

For industrial washer buyers, quality must be supported by material checks, process inspection, calibrated equipment and batch records for standard flat washers, hardened structural washers and wedge-lock washers.

Send specs → get a quote

Quality Control Flow

From incoming material to batch traceability — with anomaly stop-and-recheck at every inspection gate.

1. IQCMaterial cert + heat no.

2. First ArticleCheck before batch run

3. IPQCPatrol: size + HV

4. FQCSize, HV, appearance

5. TraceabilityBack to heat lot + record

Anomaly StopRe-check on deviation at any inspection gate

Documents on order: mill cert · inspection report · calibration · CoC

Inspection Workflow

Each stage gives buyers a clear inspection point from material receiving to shipment release.

Stage	What We Check
IQC - Incoming Inspection	Verify material certificates, heat numbers and incoming specifications.
First Article Inspection	Check first pieces before batch production starts.
IPQC - In-Process Patrol	Sample key dimensions and hardness during production, especially for DIN 127B spring lock washers and hardened structural washer orders.
Anomaly Response	Stop and re-check when die wear, clearance deviation or dimensional issues are found.
FQC - Final Inspection	Final sampling for dimensions, hardness and appearance before sample sets or bulk shipment release.
Batch Traceability	Trace finished parts back to material, press batch, heat treatment lot and inspection record.

Inspector measuring a washer with a digital caliper

Inspection Equipment

Equipment and calibration records support dimensional and hardness checks.

Vernier Caliper

S_CAL PRO 150 for dimensional inspection.

Outside Micrometer

Mitutoyo 293-348-30 for precision measurement.

Hardness Tester

TIME-HV10 for hardness inspection.

SZY Quality Management

ISO 9001:2015 certified quality management system. Certificate scope and details.

ISO 9001:2015 Quality Management System

Shengzhenyuan Metal Manufacturing (Liaocheng) Co., Ltd. (SZY) is certified to GB/T 19001-2016 / ISO 9001:2015 within the scope stated on its certificate.

Certification Scope

Manufacture of hardware products (door buckles, hinges, flat washers).

Certificate and Issuer

Certificate No. 71626Q01544R001
Shandong Saige Certification Technology Co., Ltd.

Certificate Holder

Shengzhenyuan Metal Manufacturing (Liaocheng) Co., Ltd.

Certification Standard

GB/T 19001-2016 / ISO 9001:2015.

Certificate Dates

Issued: 29 August 2026
Expiry date stated on the certificate: 28 August 2029.

Continued Validity

Continued validity is subject to successful periodic surveillance audits.

View certificate (PDF, English)

Verify the current certificate status through the certification body's official inquiry service using the certificate number and the certificate holder's registered Chinese name: 晟圳源金属制造（聊城）有限公司.

Quality documents: mill certificates, inspection reports, calibration records and certificates of conformance can be prepared according to confirmed order requirements.

Send specs → get a quote