{"id":4969,"date":"2026-01-16T10:00:47","date_gmt":"2026-01-16T01:00:47","guid":{"rendered":"https:\/\/ohtavn.com\/?post_type=media&p=4969"},"modified":"2026-01-09T17:56:18","modified_gmt":"2026-01-09T08:56:18","slug":"the-latest-screw-technology-trends-adopted-by-vietnamese-manufacturing-industry","status":"publish","type":"media","link":"https:\/\/ohtavn.com\/en\/media\/the-latest-screw-technology-trends-adopted-by-vietnamese-manufacturing-industry\/","title":{"rendered":"The latest screw technology trends adopted by Vietnamese manufacturing industry"},"content":{"rendered":"

Introduction<\/span><\/h3>\n

In Vietnam’s manufacturing sector, advancements in electrification, high functionality, and shorter delivery times are raising the standards for corrosion resistance, anti-loosening, and traceability required of screws (fasteners).
\nThis article provides a practical overview of the key points of <\/span>the latest screw technology in Vietnam<\/span><\/strong>. It explains surface treatment and hydrogen embrittlement countermeasures, transverse vibration testing (Junker-type), torque and angle management with IoT, thread-forming screws, and preventive measures based on IATF\/ISO, complete with implementation procedures and checklists.
\nThis is intended for personnel in charge of quality, production engineering, and procurement. The goal is to achieve results verification, standardization, and mass production deployment within 90 days.<\/span><\/p>\n

Basics of Standards\/Environmental Compliance and Conformity<\/span><\/h3>\n

When mass-producing or procuring screws in Vietnam, it is crucial to distinguish between standards (the language of drawings) and conformity (the language of laws and certifications). This section outlines how to write specifications on drawings, key points for selecting environmentally friendly surface treatments, practical measures to avoid hydrogen embrittlement, and the essentials of local conformity procedures.<\/span><\/p>\n

Organizing the Relationship Between TCVN\/QCVN and ISO\/JIS<\/span><\/h4>\n

TCVN (Vietnam Standards) are <\/span>voluntary<\/span><\/strong>, while QCVN (National Technical Regulations) are <\/span>mandatory<\/span><\/strong>. For screw design and manufacturing, descriptions based on <\/span>ISO\/JIS<\/span><\/strong> are mainstream from the perspective of international harmonization. Specifying the following three points on drawings can reduce differences in interpretation among suppliers:<\/span><\/p>\n

    \n
  • Size\/Grade<\/span><\/strong>: e.g., M6\u00d71-8g, Property Class 8.8 (ISO 898-1)<\/span><\/li>\n
  • Surface Treatment<\/span><\/strong>: e.g., Zn-Ni 8-12 \u00b5m, finish color, target friction coefficient<\/span><\/li>\n
  • Test Method<\/span><\/strong>: e.g., Friction\/axial force correlation ISO 16047, plating requirements ISO 4042<\/span><\/li>\n<\/ul>\n

    Practical Tip<\/span><\/strong>: Use both <\/span>English and Vietnamese<\/span><\/strong> on drawings and purchasing specifications, and operate them as a set with control charts (incoming inspection, plating lot traceability). Audits will check the <\/span>three-way link<\/span><\/strong> of “Standard \u2192 Test \u2192 Record.”<\/span><\/p>\n

    Environmentally Friendly Surface Treatments and Hydrogen Embrittlement Countermeasures<\/span><\/h4>\n

    For projects requiring RoHS\/ELV compliance, hexavalent chromium-free <\/span>Zn-Ni<\/span><\/strong> and <\/span>zinc flake<\/span><\/strong> (non-electrolytic) are leading candidates. Since electrolytic plating increases the risk of <\/span>hydrogen embrittlement<\/span><\/strong> in high-strength materials, the following controls are essential:<\/span><\/p>\n

      \n
    • Optimization of Pre-treatment<\/span><\/strong>: Minimize acid pickling time and concentration to suppress hydrogen absorption.<\/span><\/li>\n
    • Baking<\/span><\/strong>: Perform dehydrogenation treatment after plating, typically at <\/span>190 \u00b1 10 \u00b0C for 2-4 hours<\/span><\/strong>.<\/span><\/li>\n
    • Hardness Threshold Management<\/span><\/strong>: Implement stricter controls for high-strength materials (\u76ee\u5b89 <\/span>HV\u2267320<\/span><\/strong> equivalent).<\/span><\/li>\n
    • Agreement on Friction Coefficient<\/span><\/strong>: <\/span>Actually measure the friction coefficient \u03bc<\/span><\/strong> (ISO 16047) before mass production, depending on the coating agent and film.<\/span><\/li>\n<\/ul>\n

      Specification Example (Excerpt)<\/span><\/strong>:<\/span><\/p>\n

      Surface Treatment: Zn-Ni 10 \u00b5m, Trivalent Chromate Finish \/ Baking: 190 \u00b0C \u00d7 3 h \/ Target Friction Coefficient: 0.12-0.18 \/ Testing: Conforms to ISO 4042, ISO 16047<\/span><\/p><\/blockquote>\n

      Non-electrolytic <\/span>zinc flake<\/span><\/strong> coating has a low risk of hydrogen embrittlement and is effective for applications requiring high corrosion resistance, such as outdoor and automotive underbody parts (see, e.g., ISO 10683). However, requirements for dimensional increase, conductivity, and appearance color must be agreed upon in advance.<\/span><\/p>\n

      Key Points for Vietnamese Laws and Conformity<\/span><\/h4>\n

      First, confirm if the target product falls within the <\/span>scope of a QCVN<\/span><\/strong>. If it does, displaying the <\/span>CR mark<\/span><\/strong> and preparing technical documentation is necessary. While many general machine parts are operated under voluntary application based on TCVN\/ISO, the jurisdiction may change if they are incorporated into electrical, pressure, or safety-related equipment. The following steps are effective in practice:<\/span><\/p>\n

        \n
      1. Classification<\/span><\/strong>: Check the application, HS code, and whether any QCVN applies.<\/span><\/li>\n
      2. Declaration of Conformity<\/span><\/strong>: Select the required certification method (third-party certification \/ self-declaration).<\/span><\/li>\n
      3. Technical File<\/span><\/strong>: Store a complete set of drawings, material certificates, surface treatment specifications, test reports (ISO 16047, ISO 4042, etc.), and lot traceability records.<\/span><\/li>\n
      4. Marking and Labeling<\/span><\/strong>: As required, add <\/span>Vietnamese language labels<\/span><\/strong>, the CR mark, and manufacturer information.<\/span><\/li>\n
      5. Audit Response<\/span><\/strong>: Link incoming inspection records and change management (for surface treatment conditions, plating supplier changes, etc.) with the QMS.<\/span><\/li>\n<\/ol>\n

        Checklist (Excerpt)<\/span><\/strong>:<\/span><\/p>\n

          \n
        • TCVN\/ISO <\/span>drawing numbers and test methods<\/span><\/strong> are specified on the drawing.<\/span><\/li>\n
        • RoHS\/ELV compliance certificates<\/span><\/strong> and <\/span>baking conditions<\/span><\/strong> are written in the purchasing specifications.<\/span><\/li>\n
        • There is a flow to check the <\/span>friction coefficient\/axial force<\/span><\/strong> with lot samples during incoming inspection.<\/span><\/li>\n
        • The applicability of QCVN has been checked, and if necessary, the <\/span>CR mark<\/span><\/strong> and technical documents are prepared.<\/span><\/li>\n
        • Vietnamese instruction manuals\/labels<\/span><\/strong> and traceability ledgers are updated.<\/span><\/li>\n<\/ul>\n

          Fastening Reliability and Digital Quality Management<\/span><\/h3>\n

          Most fastening failures stem from “unexpected loosening,” “friction variations,” and “missing records.” This section presents a three-pronged approach:
          \n1) visualizing effective countermeasures with transverse vibration testing,
          \n2) managing mass production with torque x angle and IoT
          \n3) implementing preventive measures through a QMS.<\/span><\/p>\n

          Evaluation by Junker-type Transverse Vibration Test<\/span><\/h4>\n

          Objective<\/span><\/strong>: To reproduce clamp load reduction under transverse vibration (Junker) and quantitatively compare combinations of washers, nuts, and coating agents.<\/span><\/p>\n

          Key Points for Test Design<\/span><\/strong><\/p>\n

            \n
          • Use bolts and nuts from the <\/span>same lot as mass production<\/span><\/strong> (matching material, heat treatment, and surface treatment).<\/span><\/li>\n
          • Match the <\/span>bearing surface roughness<\/span><\/strong>, tightening force, and clamped part hardness to the actual machine.<\/span><\/li>\n
          • Define cycle conditions (amplitude, frequency, load) based on the <\/span>operating environment<\/span><\/strong> (e.g., \u00b10.3 mm \/ 12.5 Hz \/ 10 kN).<\/span><\/li>\n
          • Set the <\/span>initial clamp load<\/span><\/strong> to the center of the mass production target value and repeat the test <\/span>at least 3 times<\/span><\/strong>.<\/span><\/li>\n<\/ul>\n

            Judgment Example (Guideline)<\/span><\/strong><\/p>\n

              \n
            • A <\/span>residual clamp load of \u226580%<\/span><\/strong> after N cycles is considered passing.<\/span><\/li>\n
            • Select the combination with a smaller <\/span>initial sharp drop and subsequent stabilization<\/span><\/strong> in the curve.<\/span><\/li>\n<\/ul>\n

              Common Mistakes<\/span><\/strong><\/p>\n