About 302HQ (XM7) Cold Heading Wire

302HQ (XM7) cold heading wire is a specialized stainless steel wire renowned for its superior cold forming properties and high work hardening rate. With added copper, it offers enhanced ductility and formability, making it ideal for manufacturing complex and intricate components such as fasteners, pins, and rivets.

302HQ (XM7) Cold Heading Wire Chemical Compositions:

The chemical composition of 302HQ (XM7) cold heading wire typically includes:-

  • Chromium (Cr): 17-19%
  • Nickel (Ni): 8-10%
  • Copper (Cu): 3-4%
  • Carbon (C): 0.15% maximum
  • Manganese (Mn): 2% maximum
  • Silicon (Si): 1% maximum
  • Phosphorus (P): 0.045% maximum
  • Sulphur (S): 0.03% maximum

These elements contribute to its corrosion resistance, ductility, and cold forming capabilities.

302HQ (XM7) Cold Heading Wire Physical Properties:

  1. Tensile Strength: Typically between 700 to 850 MPa, reflecting its maximum stress resistance under tension.
  2. Yield Strength: Generally around 450 to 600 MPa, indicating the stress level at which the material begins to deform plastically.
  3. Elongation: Typically ranging from 35% to 55%, demonstrating its ability to stretch without breaking under tension.
  4. Density: Approximately 8.0 g/cm³, indicating its mass per unit volume.
  5. Melting Point: About 1400-1450°C, crucial for understanding its behavior under extreme temperatures.
  6. Thermal Conductivity: Around 16.3 W/m·K, signifying its ability to conduct heat.
  7. Electrical Conductivity: Typically 1.40 μΩ·m, important for applications requiring electrical connectivity.
  8. Magnetic Properties: Usually non-magnetic in the annealed condition, but may exhibit slight magnetism after cold working.

These properties collectively make 302HQ (XM7) cold heading wire suitable for various applications, including fastener manufacturing, automotive components, and precision engineering.

302HQ (XM7) Cold Heading Wire Mechanical Properties:

  1. Tensile Strength: Typically between 700 to 850 MPa, indicating the maximum stress the material can withstand while being stretched or pulled before breaking. It reflects its structural integrity and load-bearing capacity.
  2. Yield Strength: Generally around 450 to 600 MPa, representing the stress level at which the material begins to deform plastically, indicating its ability to return to its original shape after deformation.
  3. Elongation: Typically ranging from 35% to 55%, demonstrating the material’s ability to stretch or elongate before rupture, crucial for applications requiring ductility and formability.
  4. Hardness: Usually in the range of 85 to 95 HRB (Rockwell B Hardness) or 180 to 220 HV (Vickers Hardness), indicating its resistance to indentation or scratching, essential for assessing its wear resistance and machinability.
  5. Modulus of Elasticity (Young’s Modulus): Approximately 193 GPa, representing the material’s stiffness or resistance to deformation under stress, crucial for understanding its behavior under load.
  6. Impact Strength: Usually not specified directly for cold heading wire, but it indirectly relates to the material’s toughness, which is influenced by its composition, microstructure, and processing conditions.

These mechanical properties collectively determine the performance and suitability of 302HQ (XM7) cold heading wire for various applications, including fastener manufacturing, automotive components, and precision engineering.

302HQ (XM7) Cold Heading Wire Applications:

Some common applications include:-

  1. Fastener Manufacturing: Used to produce high-quality bolts, screws, nuts, and rivets for automotive, construction, and industrial applications due to its superior cold forming capabilities and corrosion resistance.
  2. Automotive Components: Employed in the production of automotive fasteners, pins, and clips due to its high tensile strength, corrosion resistance, and suitability for cold heading processes.
  3. Precision Engineering: Utilized for manufacturing intricate components such as shafts, dowels, and connectors requiring precise dimensions and high strength in industries like aerospace, electronics, and machinery.
  4. Construction: Used for manufacturing construction fasteners and anchor bolts due to its corrosion resistance, durability, and ability to withstand harsh environmental conditions.
  5. Electrical and Electronics: Employed in the production of electrical connectors, terminals, and small precision components due to its excellent electrical conductivity, corrosion resistance, and formability.
  6. Marine Industry: Utilized for manufacturing marine hardware, rigging components, and fasteners due to its resistance to corrosion in marine environments.
  7. Medical Devices: Used in the fabrication of surgical instruments, orthopedic implants, and medical equipment components due to its biocompatibility, corrosion resistance, and ease of sterilization.

These applications highlight the versatility and reliability of 302HQ (XM7) cold heading wire across various industries where cold forming, corrosion resistance, and mechanical strength are critical requirements