304 · 316 · 316L Stainless DIN & ASME / USS / SAE OEM & Non-Standard ISO 9001:2015
Quality & Inspection

Quality you can document.

We treat a washer as a controlled part, not a commodity — material verified on the way in, dimensions checked against DIN and ASME, surfaces inspected, and the paperwork prepared so your goods-in and compliance teams have what they need to sign it off.

ISO 9001:2015 EN 10204 3.1 MTC Dimensional report PMI on request Salt-spray on request
QC Process

Five control points, from coil to carton.

Quality is checked at the stages where defects actually enter a washer — incoming material, forming dimensions, surface condition and packing. Here is what we look at and how.

01

Incoming material verification

Every lot of 304, 316 or 316L is received against its mill test certificate and matched to the heat / melt number. Positive material identification (PMI) by handheld XRF is available on request to confirm grade before parts are formed.

02

Dimensional inspection

Outer diameter, inner diameter, thickness and flatness are measured against the applicable standard — DIN 125 / 9021 / 433 / 127 or ASME B18.21.1 / USS / SAE — using calipers, micrometers, plug and go / no-go gauges, with first-article checks on new tooling.

03

Visual & surface check

Parts are inspected for burrs, cracks, deformation, tooling marks and finish consistency. Passivated, bright, polished or coated surfaces are checked against the agreed condition so the lot looks and behaves uniformly in your assembly.

04

Salt-spray testing

For coated or coastal-duty parts, neutral salt-spray (NSS) corrosion testing is available on request to verify finish performance. Useful when you are specifying 316 / 316L or a plated finish for a marine or chemical environment.

05

Packing & quantity check

Before sealing, lots are verified for count, labeling, grade marking and export packing condition. Cartons and pallets are checked against the packing list and HS-code documentation so the shipment clears and reconciles cleanly at your dock.

Sorted stainless steel washers inspected and ready for packing
304316

Checked, then shipped

Inspection & documentation

Inspection results inform the documents you receive — so the certificate in the box matches the parts in the box.

Documentation

Documentation you can request.

Distributors and OEM buyers need more than a part — they need the paperwork that lets the part into a regulated supply chain. We prepare the records below; material and test documents are available on request and quoted with the order.

EN 10204 3.1 mill test certificate (MTC)

The 3.1 certificate ties your washers to a specific melt, with the chemical composition and mechanical properties of the stainless. The core traceability document for export and audited supply chains — available on request.

Dimensional inspection report

A measured report of the key dimensions — OD, ID, thickness — against the specified standard or your drawing, with the gauges and instruments used. Available on request, including first-article reports for new or custom tooling.

RoHS / REACH declaration

Material compliance declarations for restricted substances, to support CE-marked assemblies and EU-market shipments. Available on request for the relevant grade and finish.

PPAP for automotive

Production Part Approval Process submission packages for automotive and Tier-1 customers — built around your specific part, level and submission requirements. Available on request; scope agreed at quotation.

Management-system certification

Our quality-management system is certified to ISO 9001:2015. Part-level material certificates (MTC / EN 10204 3.1) and the test reports above are available on request.

ISO 9001:2015 · Certified

Quality management system

Certified to ISO 9001:2015 / GB/T 19001-2016 for the manufacturing and sales of stainless steel washers. Certificate No. 74326Q00174R001, issued by Origin Certification (Shanghai) — CNAS / IAF accredited — valid to 23 Apr 2029.

Automotive support

Automotive & Tier-1 programs

Our active management-system certification is ISO 9001:2015 (we are not IATF 16949 certified). For automotive and Tier-1 work we still support PPAP submission packages and full material / dimensional documentation on request — tell us your part and submission level.

Measured Against

We inspect to the standard you specify.

Tell us the standard — metric DIN or imperial ASME / USS / SAE — and we measure to its dimensions, tolerance class and surface condition. The reference tables we work from are published on our standards pages so you can specify with confidence.

Inspection pointWhat we checkMethod / tool
Material grade304 / 316 / 316L vs MTCMTC review · PMI (XRF) on request
Outer diameterOD vs standard / drawingCaliper · micrometer
Inner diameterID & hole fitCaliper · go / no-go gauge
ThicknessGauge vs standardMicrometer
Surface / finishBurrs · marks · finishVisual inspection
Corrosion (coated)Finish durabilityNeutral salt-spray on request
Representative inspection points — full inspection plan agreed per order and standard.
Need a specific certificate or test? Just ask.

Tell us the documents your supply chain requires — a 3.1 MTC, a dimensional report, a RoHS / REACH declaration, a PPAP package or a salt-spray result — and we will confirm scope, format and cost with your quote.

Ask about documentation
Request a Quote

Tell us what you need.

Send specs or a drawing and we will come back with pricing, lead time and material options. No account, no minimum to ask.

  • 304 / 316 / 316L, DIN & ASME or custom
  • Replies from engineers, typically within one business day
  • Samples and material certificates available

We reply by email. Your details are used only to answer your inquiry.

Request a Quote