DW-HF-25kw Induction Heating Equipment
DW-HF-25kW Induction Heating Equipment for Brazing, Hardening and Heat Treatment | Engineering Selection Guide
Table of Contents
- Quick Answer
- Product Overview
- Key Applications
- Suitable Materials
- Working Principle
- Technical Specifications
- Recommended Applications
- Process Workflow
- Induction Coil Selection
- Common Problems and Solutions
- Engineering Selection Guide
- Advantages
- Limitations
- Why Choose HLQ Induction Equipment?
- FAQ
The DW-HF-25kW Induction Heating Equipment is a compact high-frequency induction heater designed for brazing, hardening, annealing, soldering, shrink fitting, preheating and localized metal heat treatment. With 25kVA output power and a 30–80kHz working frequency range, it is suitable for copper, brass, carbon steel, stainless steel, carbide tools, small shafts, gears, bearings, pipe fittings and precision metal parts. It helps workshops replace flame heating with faster, cleaner and more controllable non-contact heating, improving heating repeatability, energy efficiency, operator safety and production quality.
Quick Answer
The DW-HF-25kW Induction Heating Equipment is a high-frequency induction heating machine suitable for small and medium metal parts requiring fast localized heating. It is best used for copper tube brazing, carbide tool brazing, stainless steel brazing, small shaft hardening, gear tooth hardening, annealing, soldering, bolt heating, bearing heating and shrink fitting. Compared with gas flame heating, it provides faster heating speed, cleaner operation, lower oxidation, more precise heating control and better repeatability for batch production.
Product Overview
The DW-HF-25kW induction heating equipment is a practical industrial heating system for workshops that need clean, efficient and controllable metal heating. It is especially suitable for applications where the heating area is small or medium-sized, the workpiece requires fast heating, and the production process needs better repeatability than manual flame heating.
The system usually includes a high-frequency induction power supply, separate transformer or extension unit, induction heating coil, cooling water circuit and control panel. During operation, the induction coil does not touch the workpiece. The metal part is heated by electromagnetic induction, which means heat is generated inside the workpiece itself instead of being transferred from an external flame.
This model is more powerful than a small 15kW induction heater and is better suited for larger copper joints, medium-sized carbide tools, small gears, medium pins, bushings, bolts, stainless steel fittings and localized hardening tasks. Its 30–80kHz frequency range is suitable for fast surface heating, brazing and shallow-to-medium localized heat treatment.
For buyers, the DW-HF-25kW machine is a good balance between compact size, useful heating capacity and flexible application range. It can be used in repair workshops, HVAC pipe production, tool manufacturing, mechanical parts manufacturing, automotive parts production, hardware processing, bearing assembly, electrical connector manufacturing and small heat-treatment workshops.
Key Applications
1. Induction Brazing
The DW-HF-25kW induction heater is widely used for brazing copper, brass, steel, stainless steel and carbide components. Typical brazing applications include copper tube joints, brass fittings, carbide cutting tools, diamond tools, saw blade tips, HVAC pipe assemblies, stainless steel pipe joints and electrical connectors.
Induction brazing provides fast and even heating around the joint area. Compared with torch brazing, it reduces operator dependence, improves repeatability and helps achieve cleaner brazed joints when the correct filler metal, flux and coil design are used.
2. Induction Hardening
This model can be used for localized surface hardening of small shafts, pins, bushings, gear teeth, sprockets, rollers and wear surfaces. The induction coil heats only the required surface area. After heating, water or polymer quenching is applied to form a hard wear-resistant layer while keeping the core tough.
3. Induction Annealing
The machine can anneal stainless steel tubes, copper parts, brass components, small formed parts, wires and springs. Annealing reduces hardness, improves ductility, relieves internal stress and prepares the part for bending, forming or further machining.
4. Induction Shrink Fitting
The DW-HF-25kW induction heater can heat bearings, gears, rings, sleeves and couplings for shrink fitting. The outer component expands after heating and can be assembled onto a shaft. After cooling, the component contracts and forms a tight interference fit.
5. Induction Soldering
For electrical connectors, terminals, copper contacts and precision components, induction heating provides localized soldering with less thermal influence on surrounding areas. This is useful for controlled production where overheating must be avoided.
6. Localized Preheating
The equipment can also be used for local preheating before welding, bending, forming, coating, bonding or assembly. It is useful when only a small section of the part needs to be heated quickly.
Suitable Materials
| Material | Typical Applications | Heating Suitability |
|---|---|---|
| Copper | Copper tube brazing, busbars, electrical connectors | Suitable, but copper requires good coil coupling because of high thermal conductivity. |
| Brass | Valves, fittings, plumbing components, connectors | Very suitable for brazing, soldering and localized heating. |
| Carbon Steel | Shafts, pins, bolts, bushings, small gears | Excellent for hardening, annealing, preheating and shrink fitting. |
| Alloy Steel | Tools, gears, mechanical wear parts | Suitable for hardening, tempering and heat treatment. |
| Stainless Steel | Pipe joints, fittings, medical parts, food-grade components | Suitable; heating speed depends on grade, size and magnetic properties. |
| Carbide | Cutting tools, drill bits, mining tools, saw blades | Commonly brazed to steel holders using induction heating. |
| Aluminum | Small fittings, selected brazing or heating applications | Possible, but requires careful temperature control and suitable coil design. |
Working Principle
The DW-HF-25kW induction heating equipment works by electromagnetic induction. When high-frequency alternating current flows through the induction coil, an alternating magnetic field is generated around the coil. When a conductive metal workpiece is placed inside or near this magnetic field, eddy currents are induced in the metal.
These eddy currents flow through the electrical resistance of the metal and generate heat. In ferromagnetic materials such as carbon steel, magnetic hysteresis also contributes to heating below the Curie temperature. Because heat is generated directly inside the workpiece, induction heating can be much faster and more localized than flame heating or furnace heating.
The heating result depends on frequency, power, coil shape, coil-to-workpiece distance, material type, workpiece size and heating time. For brazing, the goal is to heat the joint area evenly until the filler metal flows. For hardening, the goal is to heat the surface quickly to the austenitizing temperature before quenching. For shrink fitting, the goal is to heat the outer component uniformly enough to expand it without overheating.
Technical Specifications
| Parameter | Specification | Notes |
|---|---|---|
| Model | DW-HF-25KW-B | High-frequency induction heating equipment |
| Rated Output Power | 25kVA | Suitable for small and medium metal heating tasks |
| Input Power | 3-phase 380V, 50–60Hz | Voltage can be customized according to local power supply conditions |
| Oscillation Frequency | 30–80kHz | Suitable for brazing, soldering and localized surface heating |
| Duty Cycle | 80% at 30°C | Maintain proper cooling for continuous production |
| Host Size | 550 × 240 × 485mm | Compact structure for workshop installation |
| Extension Unit Size | 340 × 205 × 340mm | Separated design is convenient for dirty or narrow working environments |
| Approx. Weight | 55kg | Relatively easy to move compared with large induction systems |
| Cable Length | 2m standard | Longer cable may be customized depending on application |
| Cooling Method | Water cooling | Cooling water is required for coil and power components |
| Control Mode | Manual or timer control | Timer control improves repeatability for batch production |
Recommended Applications
| Application | Typical Workpiece | Recommended Coil Type | Process Notes |
|---|---|---|---|
| Copper Tube Brazing | HVAC tubes, refrigeration pipes, copper joints | Ring coil, U-shaped coil or split coil | Use suitable brazing alloy and flux; avoid overheating thin copper tube. |
| Carbide Tool Brazing | Cutting tools, drill bits, saw blades | Flat coil or profile coil | Control temperature to avoid carbide cracking or poor filler flow. |
| Small Shaft Hardening | Shaft journals, pins, bushings | Single-turn or multi-turn round coil | Quench immediately after heating to obtain surface hardness. |
| Small Gear Hardening | Gear teeth, sprockets, small transmission parts | Profile coil or round coil | Coil design must match tooth surface or required hardening zone. |
| Annealing | Stainless tubes, copper parts, brass parts | Round coil, tunnel coil or U-shaped coil | Control heating temperature to prevent overheating or oxidation. |
| Shrink Fitting | Bearings, sleeves, rings, small gears | Internal or external ring coil | Heat the outer part uniformly for safe assembly. |
| Bolt and Fastener Heating | Bolts, nuts, threaded parts | Helical coil | Useful for loosening, forming, preheating or heat treatment. |
Process Workflow
- Confirm the workpiece and heating purpose. Identify whether the process is brazing, hardening, annealing, soldering, shrink fitting or preheating.
- Select the correct induction coil. The coil must match the workpiece shape, heating area and production method.
- Connect cooling water. Check water flow, water pressure and water temperature before starting the machine.
- Install and position the workpiece. Keep a proper and consistent gap between the coil and the metal part.
- Set power and heating time. For batch production, use timer control to improve repeatability.
- Start induction heating. The workpiece heats rapidly by induced eddy currents.
- Complete the process. Apply brazing filler, quench the heated area, assemble the shrink fit or hold the annealing temperature as required.
- Inspect the result. Check brazing quality, hardness, surface condition, dimensional change or assembly fit.
- Record process parameters. Save power, time, coil type and operator notes for repeat production.
Induction Coil Selection
The induction coil is the most important process tool for this machine. Even with the correct power supply, poor coil design can cause slow heating, uneven temperature, weak brazing joints, soft hardening zones or excessive oxidation. A suitable coil should concentrate heat exactly where it is needed.
| Coil Type | Best Application | Engineering Notes |
|---|---|---|
| Round Coil | Shafts, tubes, pins, bolts | Provides uniform heating around cylindrical workpieces. |
| U-Shaped Coil | Pipe joints, side heating, repair work | Easy loading and unloading; useful for brazing assemblies. |
| Flat Spiral Coil | Tool tips, flat surfaces, small plates | Good for surface heating and brazing flat or shallow parts. |
| Profile Coil | Special-shaped parts, gear teeth, carbide tools | Customized to follow the workpiece geometry. |
| Internal Coil | Holes, sleeves, inner surfaces | Used for internal heating or bore heating applications. |
Common Problems and Solutions
| Problem | Possible Cause | Solution |
|---|---|---|
| Heating is too slow | Coil gap too large, wrong coil shape, insufficient power or oversized workpiece | Reduce coil gap, redesign coil, increase power or select a higher-power model. |
| Workpiece overheats | Heating time too long, power too high or no temperature monitoring | Reduce heating time, lower power and use timer or temperature control. |
| Brazing filler does not flow | Temperature too low, dirty joint, wrong filler metal or uneven heating | Clean the joint, select suitable filler, improve coil design and optimize heating time. |
| Hardening result is unstable | Uneven coil gap, inconsistent heating time or poor quenching | Use fixture positioning, timer control and stable quenching method. |
| Coil becomes too hot | Cooling water insufficient, blocked copper tube or poor water quality | Check water flow, clean the coil and use proper cooling water circulation. |
| Machine alarms or stops | Overcurrent, overheating, water shortage or incorrect coil connection | Check cooling, workpiece position, coil connection and operating parameters. |
| Uneven heating around the part | Workpiece not centered, coil shape not matched or inconsistent loading position | Use locating fixture, adjust coil shape and standardize loading method. |
Engineering Selection Guide
Before choosing the DW-HF-25kW induction heating equipment, buyers should confirm whether the power, frequency and coil configuration are suitable for the workpiece. This model is ideal for small and medium parts requiring fast localized heating. It is stronger than a 15kW unit and more flexible for medium brazing, small hardening and general heat treatment applications.
Choose DW-HF-25kW When:
- The workpiece is small to medium-sized.
- The heating area is local rather than the entire large part.
- The application is brazing, hardening, annealing, soldering, shrink fitting or preheating.
- The factory has 3-phase 380V power available.
- The user needs faster heating than a 15kW unit.
- The process requires repeatability for batch production.
- The heating quality must be cleaner and more controllable than flame heating.
Consider a Larger Model When:
- The workpiece is large, thick or heavy.
- The target heating time is very short.
- The application requires deep hardening or large heating depth.
- The production line runs continuously at high load.
- The material is highly conductive and requires more power, such as large copper components.
Advantages
- Fast heating: Heat is generated directly inside the metal workpiece.
- Clean process: No open flame, less smoke and lower surface oxidation.
- Localized heating: Only the required area is heated, reducing thermal distortion.
- Good repeatability: Timer control improves heating consistency for batch production.
- Flexible application: Suitable for brazing, hardening, annealing, soldering, shrink fitting and preheating.
- Compact structure: Easy to install in workshops and production cells.
- Separated design: The extension unit is convenient for complex or dirty working environments.
- Energy efficient: Direct electromagnetic heating reduces unnecessary heat loss.
- Improved operator safety: Reduces flame risk and improves workplace conditions.
- Custom coil compatibility: Coils can be designed according to different workpieces.
Limitations
- The 25kW power level is not suitable for very large or heavy workpieces.
- Cooling water is required during operation.
- Different workpieces usually require different induction coils.
- Precision temperature control may require an external pyrometer or temperature feedback system.
- Highly conductive materials such as large copper parts may require more power or optimized coil design.
- For large forging, melting or deep hardening, a medium-frequency or higher-power system may be required.
Why Choose HLQ Induction Equipment?
HLQ Induction Equipment provides industrial induction heating solutions for brazing, hardening, annealing, forging, melting, shrink fitting, preheating and customized heat treatment applications. For the DW-HF-25kW model, HLQ can support customers with equipment selection, coil design, application testing and process recommendations.
The real performance of an induction heater depends not only on the power supply, but also on coil design, workpiece positioning, cooling water, process parameters and operator method. HLQ can help buyers select the right power level, frequency range, coil structure and process workflow according to actual production requirements.
For OEM production, repair workshops and small-to-medium manufacturers, HLQ can provide customized induction coils, technical guidance and complete heating solutions for copper brazing, carbide tool brazing, shaft hardening, gear hardening, bearing heating and local metal heat treatment.
FAQ
1. What is the DW-HF-25kW induction heating equipment used for?
It is used for brazing, hardening, annealing, soldering, shrink fitting, preheating and localized metal heat treatment of small and medium workpieces.
2. What power supply does this machine require?
The standard model uses 3-phase 380V, 50–60Hz input power. Other voltages may be customized according to local requirements.
3. What is the frequency range?
The working frequency range is 30–80kHz, suitable for high-frequency localized heating, brazing and surface heat treatment.
4. Can it be used for copper tube brazing?
Yes. It is suitable for copper tube brazing, brass fittings, HVAC pipe joints, refrigeration pipe joints and small metal connectors when matched with the correct induction coil.
5. Can it harden steel parts?
Yes. It can harden small shafts, pins, bushings, small gears, sprockets and wear surfaces. For larger parts or deeper hardening, a higher-power model may be required.
6. Does the machine need cooling water?
Yes. Cooling water is required for the induction coil, extension unit and power components. Stable water flow helps protect the equipment and coil.
7. Can one coil heat all workpieces?
No. The induction coil should be designed according to the workpiece shape, size and heating area. Different applications usually require different coils.
8. Is the DW-HF-25kW suitable for batch production?
Yes. With timer control, fixtures and proper coil design, it can be used for repeatable small-batch and medium-batch production.
9. What is the difference between 15kW and 25kW induction heaters?
The 25kW model provides higher heating capacity and is more suitable for larger joints, thicker parts and faster production cycles than a 15kW model.
10. What is the duty cycle of this machine?
The listed duty cycle is 80% at 30°C. Proper cooling and reasonable operating conditions are required for stable long-term use.
11. Can HLQ provide customized induction coils?
Yes. HLQ can design induction coils for brazing, hardening, annealing, shrink fitting, soldering and special heating applications according to drawings or samples.
12. What information should I provide for quotation?
Please provide workpiece material, dimensions, photos or drawings, heating purpose, target temperature, required heating time, production quantity and available power supply.
