Outside Scarfing Inserts for ERW Tube Mill

What Is an Outside Scarfing Insert?

During ERW pipe production, the strip edges are heated and welded together by high-frequency current. This process creates an external weld bead along the pipe seam.

An outside scarfing insert removes this excess material immediately after welding, improving surface finish and preparing the tube for downstream sizing and finishing operations.

Main Benefits

• 🔹Removes external weld bead efficiently

• 🔹Improves pipe surface quality

• 🔹Reduces secondary finishing work

• 🔹Supports stable high-speed production

• 🔹Lowers tooling costs through multiple usable edges

Position in an ERW Tube Mill

The outside scarfing unit is typically installed after the HF welder and squeeze rolls.

Typical Production Flow

Coil → Forming → HF Welding → Squeeze Rolls → Outside Scarfing → Cooling → Sizing → Cut-Off

At this stage, the weld bead can be removed efficiently before the tube enters the cooling and sizing sections.

Working Principle of Outside Scarfing Inserts

Outside scarfing inserts do not work independently. They are mounted on a scarfing tool holder, also known as a knife bar, which provides positioning, support, and adjustment.

Step 1 – Insert Installation🔧

The carbide insert is securely mounted onto the scarfing tool holder.

Step 2 – Tool Position Adjustment🛠

The operator adjusts the cutting angle and cutting depth according to pipe size and weld bead height.

Step 3 – Weld Bead Removal✂

As the welded tube travels forward, the insert contacts only the external weld bead and continuously removes the excess material.

Step 4 – Smooth Surface Formation📐

The removed bead separates from the pipe surface, leaving a clean and smooth weld area ready for cooling and sizing.

Because the process is continuous, the tube mill can maintain high production speeds without interrupting production.

Available Insert Types

AIS Machinery offers several insert configurations to suit different production requirements.

4-Edge Inserts (Square)

• Four usable cutting edges
• Economical and widely used
• Easy indexing and replacement

6-Edge Inserts (Hexagonal)

• Six usable cutting edges
• Longer service life
• Better carbide utilization

8-Edge Inserts (Octagonal)

• Eight usable cutting edges
• Maximum edge utilization
• Ideal for high-volume production

Technical Specifications

💡Custom sizes can be manufactured according to drawings or samples.

How to Select the Right Insert

When selecting an outside scarfing insert, consider:

Pipe Material

Different materials require different carbide grades and wear resistance levels.

Tube Size and Wall Thickness

Larger pipes and thicker walls generally produce larger weld beads and may require more durable inserts.

Production Speed

High-speed mills often benefit from 6-edge or 8-edge inserts due to longer service life and reduced downtime.

Tool Holder Compatibility

Always confirm insert dimensions and mounting structure to ensure compatibility with the existing knife bar.

AIS Machinery can recommend suitable insert types based on your tube specifications and production requirements.

FAQ

What is an outside scarfing insert used for❓

It removes the external weld bead created during the ERW welding process, resulting in a smoother pipe surface.

Does the insert work without a tool holder❓

No. The insert must be installed on a scarfing tool holder (knife bar), which provides support and adjustment.

Why choose 6-edge or 8-edge inserts❓

More cutting edges mean longer service life, better carbide utilization, and lower tooling costs.

What material are the inserts made from❓

Most outside scarfing inserts are manufactured from high-quality tungsten carbide for excellent wear resistance.

Can AIS Machinery provide customized inserts❓

Yes. We can manufacture inserts according to customer drawings, dimensions, or samples.

Why Choose AIS Machinery?

AIS Machinery specializes in ERW tube mill equipment and spare parts. Our outside scarfing inserts are designed for reliable weld bead removal, long service life, and stable production performance.

What We Offer

• 4-edge, 6-edge, and 8-edge carbide inserts
• Custom manufacturing services
• Technical selection support
• Fast response and delivery
• Professional ERW tube mill experience

Whether you need replacement inserts or tooling for a new production line, AIS Machinery can provide a suitable solution.

Why Choose Our Machine?

We focus on equipment for ERW tube mills and pipe production lines. Our grinding machines are:

• Designed based on real tube mill working conditions

• Manufactured with strict quality control

• Exported to multiple countries

• Supported by professional technical service

We provide customized solutions to match your blade type and production speed.

1. Why Choose Us?

2. 1.Leading Technology, Reliable Quality, Excellent Service! Optimized Design, High quality material select!  Heat treatment process guarantee!

3. 2.Spiral bevel gear, drum gear coupling and carburization. Gear teeth quenching. Driven system stable, efficient and wearable with lower noise.

4. 3.High precision wear resisting and Long life of toolings. All the machine Lathes, Key Grooves are positioned and Milled by CNC.

5. 4.Quality department make sure the material of the raw materials quality, and ensure the machine running perfect.