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4XXX Series Aluminum Welding Filler

-- Steady & Reliable Manufacturer --

Intro

A dedicated family of aluminum filler metals based on the Aluminum-Silicon system, optimized for low melting temperatures, high fluidity, and welding heat-treatable and cast base metals.

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Introduction

The 4XXX series (e.g., ER4043, ER4047) are the most widely used aluminum filler metals globally, prized for their excellent fluidity due to the addition of Silicon (Si). This low-melting, high-flow characteristic makes them ideal for intricate, thin-gauge, and cast aluminum welding, minimizing the risk of burn-through and improving aesthetic bead appearance. While generally lower in strength than 5XXX series, they are the preferred choice for heat-treatable base metals (like 6XXX series) where minimizing cracking is a primary concern.

Specification

Alloy BaseAluminum-Silicon (Al-Si)
Primary GradesER4043 (5% Si), ER4047 (12% Si - lower melting point)
Key PropertyHigh fluidity, Low melting point, Crack resistance
Post-WeldGenerally non-heat-treatable (except specialized variants)
ColorWeld deposit often darkens (smuts) after anodizing

Applications

  • Welding the 6XXX series structural alloys (e.g., 6061, 6063) in general fabrication.

  • Joining thin-gauge aluminum sheet metal and tubes in HVAC and automotive heat exchangers.

  • Repair and fabrication of cast aluminum components (engine blocks, castings).

  • Applications where the finished weld must be aesthetically appealing and easy to finish.

FAQ

  • Q: Why does 4XXX series wire sometimes turn black after anodizing?
  • A: The high silicon content in the weld deposit does not respond to the anodizing process in the same way as the base aluminum. The silicon appears as a dark grey or black smut, creating a visible contrast.
  • Q: What is the main difference between ER4043 and ER4047?
  • A: ER4047 has a higher silicon content (approx. 12% vs. 5% in ER4043), giving it a lower melting point, making it even more fluid and better for brazing, thinner joints, and cast component repair.

Advantages

  • Superior Crack Resistance: Silicon significantly lowers the freezing temperature range, reducing solidification shrinkage and mitigating hot cracking on crack-sensitive base metals.

  • Excellent Flow and Wetting: The high fluidity allows the filler metal to bridge gaps easily and flow smoothly into joints, ideal for manual and robotic welding.

  • Low Burn-Through Risk: The lower melting point is perfect for high-speed welding of thin materials.

  • Versatile: Compatible with a wide range of popular 6XXX and 3XXX base materials.

Payment and Shipping

  • Bulk Availability: High-volume stock of ER4043, the most widely consumed aluminum filler metal globally.

  • Technical Data: Detailed MTCs specifying silicon and other trace element content for crack prediction.

  • Packaging: Available in all standard spool sizes, TIG rods, and bulk drums.

About Us

Coming From China, Marketing To The World.

Hangzhou Kunli welding materials Co., Ltd. is China 4XXX Series Aluminum Welding Filler Manufacturers and Wholesale 4XXX Series Aluminum Welding Filler OEM/ODM Suppliers. We are located in the industrial zone of Puyang Town, Xiaoshan District, Hangzhou, Zhejiang Province. It is a high-technology enterprise specializing in the research, development and manufacturing of high-performance. The company has more than 20 years of aluminum alloy wire production experience, with international advanced manufacturing equipment, complete testing equipment,stable production process and strict quality control system.
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