How to Control Tooling Wear in Tube End-Forming Machines

author: Huashun Machinery

2025-06-20

The molds in Tube End-Forming Machine typically include the following major types:

1. Outer Die (Clamping Die Set)

The outer die functions to wrap around the external surface of the tube and apply forming pressure to shape the tube end. A common structure consists of multiple die segments forming a circular clamping assembly.

Each die segment features an inner arc surface that is fastened to an intermediate pad block.

The inner arc surface of the pad block is further fitted with arc-shaped pressure blocks.

Advantages:

High reliability and precision in operation

Supports processing of various tube sizes and shapes

Widely applicable for medium to high-volume production

Estimated Price Range: ¥3,000 – ¥10,000+ (depending on complexity, size, and materials)

2. Split Clamp Mold (Upper and Lower Die)

This mold consists of an upper and a lower die that close together to form a complete cavity for holding and shaping the tube end.

Features:

Simple structure and easy to manufacture

Suitable for applications where high precision is not critical

Estimated Price Range: ¥1,500 – ¥5,000

3. Punch and Core Insert Combination Mold

This mold includes three key components: punch, stop plate, and forming core.

The punch features a circular groove at one end.

The stop plate and core insert are interference-fitted into this groove.

The stop plate’s end surface contacts the groove bottom, while the other side aligns with the forming core.

The core includes a central through-hole for inserting seamless steel tubes.

Material:

The forming core is made of hard alloy (carbide), providing excellent wear resistance.

Advantages:

High processing efficiency

Minimal downtime

Only the core insert needs to be replaced when worn, keeping maintenance costs low

Estimated Price Range: ¥4,000 – ¥12,000 (higher for carbide/tungsten alloy cores)

Mold Pricing Summary (Reference Only)

Process Type	Features	Reference Mold Price Range (RMB)
Reducing Mold	Commonly used for heat exchanger tubes and automotive parts	¥2000–6000
Expanding Mold	Commonly used for pipe connections and insert fittings	¥2500–7000
Flaring Mold	Requires high-precision positioning and edge forming	¥3000–8000
Bulging Mold	Complex forming; high mold precision required	¥4000–10000+
Multi-Station Compound Mold	Integrates multiple processes; complex mold structure	¥10000–30000+

Structure and Cost Management of Tube End-Forming Machine Molds

Mold Structure Types

1. Modular Structure

Examples include:

The outer die, composed of die holders, pad blocks, and arc-shaped pressure blocks

The punch and core insert mold, consisting of punch, stop plate, and core insert

Advantages:

Easy to replace individual components when damaged

Reduces maintenance time and cost

Ideal for high-usage environments where component wear is common

2. Monolithic (One-Piece) Structure

Commonly found in:

Clamp molds, where the upper and lower dies are integrally formed

Advantages:

Higher overall structural strength

Improved machining accuracy

Disadvantages:

Higher repair cost once damaged

Typically requires full replacement rather than part repair

Materials Used in Tube End-Forming Molds

1. Cemented Carbide (Hard Alloy)

Features high hardness, excellent wear resistance, and good toughness

Commonly used in core inserts, particularly for forming seamless steel tubes

Benefits:

Extended mold life

High forming efficiency

Lower long-term tooling costs

2. Tool Steel / Alloy Steel

Offers good mechanical and machining properties

Commonly used for components like outer die holders, pad blocks, etc.

3. Flexible Materials (Rubber, Plastics)

Used for soft connections between adjacent outer die segments

Allow for synchronized movement during forming operations

Help absorb shocks and reduce alignment errors

Effective Cost Control Measures for Tube End-Forming Molds

1. Scheduled Maintenance

Develop a detailed maintenance plan including cleaning, lubrication, rust prevention, tightening, and timely replacement of wear parts (e.g., ejector pins, sliders, springs)

Regularly inspect the guiding system for precision

Lubricate moving parts to reduce friction and wear

2. Daily Inspection

Operators should check molds before and after each use

Look for visible damage, abnormal wear, and ensure all parts operate smoothly

3. Material and Process Optimization

Select mold materials and manufacturing processes based on product requirements and production volume

Balance performance and cost efficiency

4. Inventory Classification and Auditing

Categorize molds by type, function, and size

Set reasonable inventory levels for each mold category

Conduct regular inventory audits to ensure accuracy between records and physical stock