Precision Internal Burr Removal for High-Quality Welded Pipes

The Internal Burr Ring Knife is a precision cutting tool used in the internal scarfing device of an ERW tube mill. It removes the internal weld bead (inside burr) immediately after high-frequency welding, helping produce a smooth inner pipe surface while maintaining the required inside diameter.

The ring knife works together with the internal scarfing holder, support mandrel, and impeder assembly. It cannot be used independently. Selecting the correct ring knife improves burr removal quality, extends tool life, and reduces production downtime.

What Is an Internal Burr Ring Knife?

The Internal Burr Ring Knife is a circular cutting insert installed on the head of the internal scarfing tool. As the welded tube moves forward, the knife continuously cuts away the excess weld bead formed inside the pipe.

Unlike conventional cutting tools, the ring knife is designed specifically for continuous ERW pipe production, providing stable cutting performance at high production speeds.

Main Functions

✅ Remove the internal welding burr

✅ Improve inner surface quality

✅ Maintain consistent pipe ID

✅ Reduce defects in downstream processing

✅ Extend the service life of the internal scarfing system

How Does It Work?

During high-frequency welding, a weld bead is generated on both the inside and outside of the tube.

The external burr is removed by the outside scarfing tool, while the internal burr is removed by the Internal Burr Ring Knife installed on the internal scarfing device.

As the pipe passes through the welding section, the ring knife contacts the weld bead and continuously cuts off the excess metal. The removed burr is then guided away through the internal scarfing mechanism.

📌Note: The Internal Burr Ring Knife must be matched with the appropriate internal scarfing holder and tube size to achieve stable cutting performance.

Internal Burr Ring Knife Specifications

Internal Burr Ring Knife vs. External Scarfing Knife

💡Both tools remove welding burrs, but they work on different sides of the welded tube and are installed in different scarfing systems.

How to Select the Right Ring Knife

When choosing an Internal Burr Ring Knife, consider:

• Pipe outside diameter (OD)
• Wall thickness
• Internal scarfing holder model
• Production speed
• Pipe material
• Required inner surface quality

A properly matched ring knife helps achieve stable cutting, longer tool life, and consistent weld quality.

Applications

The Internal Burr Ring Knife is widely used in:

• ERW steel pipe production lines
• Carbon steel tube mills
• Stainless steel tube mills
• Structural pipe manufacturing
• Mechanical tubing
• Water and gas pipe production
• Automotive tube production

Customer Success🌍

Our Internal Scarfing Devices and Internal Burr Ring Knives have been supplied to customers across Europe, the Middle East, and other international markets. They are widely used in ERW tube mills for carbon steel and stainless steel pipe production. Customers have praised their stable cutting performance, reliable quality, and long service life. With years of manufacturing experience and strict quality control, AIS continues to provide dependable internal burr removal solutions for tube producers worldwide.

FAQ

What is an Internal Burr Ring Knife used for❓

It removes the internal weld bead generated during high-frequency welding, producing a smoother inner pipe surface.

Can the ring knife be used alone❓

No. It is designed to work together with the internal scarfing device and cannot function independently.

Is it suitable for all tube sizes❓

The ring knife should be selected according to the pipe diameter, wall thickness, and internal scarfing holder. Customized sizes are available.

How often should the ring knife be replaced❓

Replacement depends on pipe material, production speed, and operating conditions. Regular inspection is recommended to maintain cutting quality.

Can it be customized❓

Yes. AIS can manufacture Internal Burr Ring Knives according to your tube mill model and production requirements.

RELATION EQUIPMENT

We provides all equipment to tube mill entry section:

Coil Car

Single And Double Heads Un-coiler & Hydraulic And Pneumatic Un-coiler

Peeler and hold down roll arm

Flattening Machine

Automatic and Semi Auto Shearer & Butt Welder

Vertical Cage Accumulator​ & Horizontal Loop Accumulator & Landing Horizontal Spiral Loop Accumulator

TUBE MILL FINISHING SECTION

We provides all equipment to tube mill Finishing section:

1. Eddy current machine

2. Seam annealing machine

3. Straightener machine

4. Chamfer and end facer machine

5. Hydro Tester machine

6. Threading machine

7. Painting and oil machine

8. Automatic bundle and package machine

SPARE PARTS TO CHOOSE

Our Spare Parts Apply:

1. Roller, Mould, Cr12, Cr12Mov material, D2,D3 material

2. Ferrite, Impeder, Fiberglass tube

3. HSS saw blades, TCT Saw blades, Friction saw blades

4. OD burr remove inserts, ID burr remover inserts

5. HF welder Induction Coil and other HF welder spare parts

6. Copper tube for induction Coil, PTFE pipe for Induction Coil

7. Mosfet, Boards

8. Steel pipe Strapping machine

9. Zinc Spray Machine, Zinc wire, Zinc spray gun

OUR CERTIFICATE

OUR SERVICE

Why Choose Us?

Leading Technology, Reliable Quality, Excellent Service!

Optimized Design, High quality material select! 

Heat treatment process guarantee!

Spiral bevel gear, drum gear coupling and carburization.

Gear teeth quenching.

Driven system stable, efficient and wearable with lower noise.

High precision wear resisting and Long life of rollers.

All the machine Lathes, Key Grooves are positioned and Milled by CNC.

Our Service

Pre-sale service

1.  We can provide machine running videos for reference

2.  We will recommend the most suitable equipment according to the needs of customers

3.  We can provide the layout of the factory

4.  We welcome customers to visit our factory 

After-sales service

1.We will delivery the machine and provide the documents on time to make sure you can get the machine quickly

2.When you finish the Preparation conditions, Our fast and professional aftersales service engineer team will go to your factory to install the machine, give you the operating manual, And train your employee until they can operate the machine well.

3.We provide one year warranty and life-long technical support.

4.Well-trained & experienced staff are to answer all your inquiries in English and Chinese

5 .24 hours for engineer response.

6.Your business relationship with us will be confidential to any third party.

Quality Control

We have the single quality department, that make sure the material of the raw materials is good, and ensure the machine running smoothly.