What Is an External Burr Scraper? Types, Benefits & Applications in Tube Mills

In modern ERW tube and pipe production, surface quality is one of the key factors that determines product value. During the welding process, excess metal is squeezed out and forms burrs on the outer surface of the pipe.

This is where the external burr scraper becomes essential.

What Is an External Burr Scraper?

An external burr scraper is a tool used in an ERW tube mill to remove the outer weld bead (external burr) formed during high-frequency welding.

After the strip edges are heated and pressed together, molten metal is squeezed out along the weld seam. If not removed, this burr will:

• Affect pipe appearance
• Interfere with downstream processing (galvanizing, coating, etc.)
• Reduce product quality

👉 The scraper trims this excess material smoothly, ensuring a clean and uniform pipe surface.

Where Is It Used in a Tube Mill?

The external burr scraper is typically installed:

➡️ After the welding section
➡️ Before sizing or cooling section

Process flow:

Uncoiling → Forming → Welding → External Burr Removing → Cooling → Sizing → Cutting

Types of External Burr Scrapers

External burr scrapers come in different designs depending on pipe size, production speed, and precision requirements.

1. Four-Sided External Burr Scraper

🧩Features:

• Uses 4 cutting edges
• Simple structure
• Easy to install and maintain

📝Advantages:

• Cost-effective
• Suitable for small to medium tube mills
• Quick replacement

🔍Limitations:

• Lower precision compared to multi-edge designs
• More frequent tool changes
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2. Six-Sided External Burr Scraper

🧩Features:

• Equipped with 6 cutting edges
• More stable cutting performance

📝Advantages:

• Longer service life
• Better surface finish
• Higher efficiency for continuous production

🔍Best for:

• Medium to high-speed production lines
• Customers requiring better pipe surface quality
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3. Multi-Edge / Adjustable Scraper Systems

🧩Features:

• Adjustable tool holders
• Replaceable inserts

📝Advantages:

• High precision
• Flexible for different pipe sizes
• Reduced downtime

🔍Used in:

• High-end tube mills
• Automated production lines

What Does It Work With?

The external burr scraper does not work alone. It is part of a complete weld seam treatment system.

Commonly used together with:

1. Internal Burr Remover (Scarfing Tool)

• Removes burr inside the pipe
• Ensures smooth inner surface

2. HF Welder (High Frequency Welder)

• Generates the weld seam where burr is formed

3. Sizing Mill

• Final shaping after burr removal

4. Cooling System

• Stabilizes pipe shape before further processing

👉 Together, these systems ensure both inner and outer weld quality.

Why Is External Burr Removal Important?

Using a high-quality external burr scraper helps to:

✔ Improve pipe appearance
✔ Ensure smooth downstream processing
✔ Reduce defects in coating or galvanizing
✔ Increase product value
✔ Meet international quality standards

How to Choose the Right External Burr Scraper?

When selecting a scraper, consider:

• Pipe diameter range
• Wall thickness
• Production speed
• Material type (carbon steel, stainless steel, etc.)
• Required surface quality

👉 For high-speed lines, a six-sided scraper is usually the better choice.
👉 For cost-sensitive projects, a four-sided scraper is often sufficient.