MICRO MACHINE NYLOCK SCREW M2-L3.5: Technical Specifications and Applications

Technical Specifications

The Micro Machine Nylock Screw M2-L3.5 is a precision-engineered fastener designed for applications requiring vibration resistance and secure fastening in compact spaces. This screw features the following technical characteristics:

• Thread Size: M2 metric thread with a pitch of 0.4 mm, conforming to ISO 68-1 standards

• Length: 3.5 mm nominal length (measured from under the head to the tip)

• Head Type: Nylock (nylon-insert) hex head with 1.5 mm hex drive (AF)

• Material: Typically manufactured from A2 or A4 stainless steel (yield strength: ≥450 MPa) or alloy steel (grade 8.8 or higher)

• Nylon Insert: PA66 nylon with 0.3-0.5 Nm prevailing torque for vibration resistance

• Surface Treatment: Optional finishes including zinc plating (5-8μm), black oxide, or passivation for corrosion resistance

• Temperature Range: Nylon insert maintains effectiveness between -40°C to +120°C

• Torque Specifications: Recommended tightening torque of 0.1-0.15 Nm for steel variants

Applications

The MICRO MACHINE NYLOCK SCREW M2-L3.5 finds extensive use in precision engineering applications where vibration resistance and compact size are critical requirements:

• Electronics Manufacturing: Securing components in PCB assemblies, mobile devices, and wearable technology where vibration could loosen standard screws

• Medical Devices: Used in surgical instruments, imaging equipment, and portable medical devices requiring reliable fastening in sterile environments

• Aerospace: Critical for avionics and satellite components where vibration resistance is paramount (often in A286 stainless steel variants)

• Automotive Electronics: Securing ECU modules, sensor housings, and dashboard components subject to constant vibration

• Precision Optics: Mounting lens assemblies and laser components where micrometer-level stability is required

• Robotics: Used in micro robotic joints and actuator assemblies where space constraints prevent larger fasteners

• Consumer Electronics: Found in smartphone assemblies, laptops, and IoT devices requiring reliable fastening in compact spaces

Maintenance and Care

Proper maintenance of MICRO MACHINE NYLOCK SCREW M2-L3.5 fasteners ensures optimal performance and longevity:

• Installation: Use precision torque drivers calibrated to 0.1-0.15 Nm range. Over-torquing can damage the nylon insert or strip threads in soft materials.

• Reusability: Nylock screws typically maintain 70-80% of original locking torque after 5-10 disassembly cycles. Replace if insertion torque falls below 0.05 Nm.

• Cleaning: For critical applications, clean with isopropyl alcohol (≥99%) and lint-free wipes. Avoid ultrasonic cleaning which may degrade nylon inserts.

• Lubrication: Generally not required for nylon inserts. For steel-on-steel applications, use molybdenum disulfide or PTFE-based lubricants sparingly (<0.5 mg per screw).

• Storage: Keep in low-humidity environments (<40% RH) at 15-25°C. Package with VCI paper for long-term storage to prevent corrosion.

• Inspection: Check for:

• Nylon insert integrity (no cracks or deformation)

• Thread damage (use optical comparators at 20x magnification)

• Corrosion (particularly important for stainless steel passivated variants)

• Thread Engagement: Ensure minimum 1.5× diameter thread engagement (≥3 mm in blind holes) for optimal strength.

Special Considerations

When working with MICRO MACHINE NYLOCK SCREW M2-L3.5 fasteners, several specialized considerations apply:

• ESD Protection: For electronics applications, use conductive nylon inserts (surface resistance 10^4-10^6 Ω) to prevent static buildup.

• Sterilization: Medical-grade variants use gamma-stable nylon that withstands 25 kGy radiation doses without embrittlement.

• Microscopic Alignment: In optical applications, apply thread-locking compounds (LOCTITE 243) to the first 1.5 threads for precise positioning before final tightening.

• Thermal Cycling: Allow for 0.05 mm expansion gap in applications experiencing >50°C temperature differentials to prevent thread binding.

• Vibration Testing: Subject to MIL-STD-810G Method 514.7 procedures when used in aerospace applications, typically surviving 5-7 Grms random vibration profiles.