To determine the authenticity of the material report (MTC/Mill Test Certificate) from the fastener supplier, it is not enough to just look at whether there is a red seal on the paper. It is not uncommon for PS to forge quality assurance certificates in the industry. It should be divided into three steps: formal review → logical consistency check → third-party verification if necessary.

📄 1、 Formal review – first check if the report is “legal” or not

Inspection items compliance characteristics danger signals

The standard reference indicates EN 10204 2.1/2.2/3.1 (3.1 if signed by a third party or authorized person) without a standard number, and the self printed “warranty certificate” has no basis

The supplier information is consistent with the contract/invoice subject, but there is a PS address, phone number, official seal or electronic signature, and the company name does not match

Authorized signature with handwritten or electronic signature by the quality manager (required by EN 10204), printed name without signature

The furnace number/batch number is consistent with the bolt packaging label and the furnace number (Lot No./Heat No.) on the delivery note. Report that the furnace number ≠ physical label ❌ (The most common form of fraud)

The testing items include: chemical composition (C/Si/Mn/P/S, etc.)+mechanical properties (Rm/Rel/A%/Z%), only write “meets standards” without data

⚠️ The first iron rule: The reported furnace number must correspond to the physical packaging label and delivery note, and there should be no direct doubt if they do not match!

🔬 2、 Data logic verification – check whether the values are reasonable or not

① Is the chemical composition within the range of steel grades

-8.8 grade medium carbon steel (such as ML40Cr/35K): C ≈ 0.32-0.45%, Mn ≈ 0.50-0.80%
• A2（304）：Cr≈18～20%，Ni≈8～10.5%，Mo＜0.5%（316 Mo≈2～3%）

-If the 304 report states Mo=2.5% → the actual value is 316, there is suspicion of passing off inferior goods as good or making false claims

② Has the mechanical performance reached the lower limit of the grade

Level 8.8: Rm ≥ 800MPa, ReL ≥ 640MPa, A ≥ 12%

A2-70: Rm ≥ 700MPa, A ≥ 40% (usually cold processed)

-The value is exactly the minimum value and all batches are the same → Be cautious (possibly due to template filling)

③ The same furnace number repeatedly appears in different batches in different months

Legitimate large factory furnace numbers have uniqueness. If the same Heat No. repeatedly appears across months and years, it is highly suspected that the old report will be used

🔍 3、 On site/third-party verification – final fallback

Applicable methods and practices

Comparison of hardness sampling with portable hardness tester for measuring HRC/HB, grade 8.8 HRC 22-32; Significantly lower (HRC<18) and conflicting with reported tensile strength for each batch or AQL sampling

Spectral composition analysis: Handheld spectrometer is used to measure the bolt head/rod, and the element content of key components/annual confirmation is compared in the report

Tensile test (third-party) sent to the local geological inspection institute for full tensile testing (Rm/ReL/elongation), comparing MTC values for mass first article/annual review

You can inquire with the furnace number from the original steel plant/major steel plants (Baosteel, Shagang, etc.); Brand fastener factories (such as Jinyi) may require the provision of important quality assurance projects for superior steel products

🚩 4、 Typical fraud/violation red flag (direct questioning)

• ❌ The reported furnace number does not match the packaging label or is not labeled with the furnace number

• ❌ The “different material reports” data provided by multiple different suppliers are completely consistent (in the same tensile strength, elongation, and furnace number format)

• ❌ The supplier refuses to provide EN 10204 2.2/3.1 and only provides a “certificate of conformity” or self-made inspection form

– ❌ Requesting an increase in price before giving the ‘official warranty certificate’ → Extremely suspicious
• ❌ 304 spectrum detected Mo 2%+but labeled A2-70 (should be A4-70 but underreported)

💬 Procurement/Quality Inspection Standard Script

Please provide an EN 10204 2.2 or 3.1 material and mechanical performance report along with the goods. The furnace number in the report must be consistent with the bolt packaging label and delivery note received by our company. We will conduct hardness/spectral sampling, and key batches will be sent for third-party tensile verification. If any discrepancies are found between the report and the actual product, the entire batch will be returned and responsibility will be pursued. “