New Manual Capacitor Discharge Projection Welder For Metal Nut Screw Spot Welding
CD Projection Welding Machine for Nut Screw and Fastener Welding Applications
Capacitor Discharge Welding for Fast, Low-Heat Nut and Screw Attachment
Combines capacitor discharge technology with manual load/unload and automatic welding operation. Delivers 10-50ms weld cycles for projection welding of nuts, screws, bolts and studs — with minimal heat impact on coated and galvanized materials.
✓ Capacitor Discharge Technology — 10-50ms Weld Cycle
✓ Dual Function — Projection Welding + Spot Welding in One Machine
✓ Grid-Friendly — Low-Power Charging, No Current Surges
✓ Factory Direct from Xinwei — Four Models from 100 to 250KVA
Watch the CD Projection Welding Process
Why Capacitor Discharge Welding?
The capacitor discharge (CD) method stores energy in a capacitor bank and releases it in a single, precisely controlled pulse — typically within 10 to 50 milliseconds. This fundamentally differs from traditional AC resistance welding in several ways that directly impact production quality and cost.
| Factor | Traditional AC Resistance Welder | Capacitor Discharge Welder |
|---|---|---|
| Welding Cycle Time | 200-500ms | 10-50ms |
| Heat Input on Workpiece | Higher, may damage coatings | Lower, preserves surface finish |
| Grid Impact | High instantaneous current surge | Low-power charging, no surge |
| Electrode Life | Shorter (sustained heat) | Longer (short pulse, less heat buildup) |
| Energy Efficiency | Transformer idle losses | Higher, charges only when welding |
| Machine Weight / Stability | Lighter construction | Heavy-duty frame, up to 2000KG (DN-250) |
Application Scenarios
Galvanized Sheet Metal Nut Welding
Requires low heat input to prevent zinc coating burn-off around the weld zone. The CD discharge pulse (10-50ms) limits the heat-affected zone, preserving corrosion resistance of galvanized nuts and plates. Suitable for electrical cabinets, automotive brackets and construction hardware components.
Stainless Steel Screw and Bolt Projection Welding
Stainless steel fasteners require consistent projection collapse with minimal oxidation. The short CD pulse reduces surface discoloration, minimizing post-weld cleaning requirements. Suitable for kitchen equipment, medical device housings and food-grade container manufacturing.
Mixed Fastener Batch Production
The manual load/unload + automatic weld operating mode enables rapid changeover between different nut sizes, screw types and stud bolt specifications. Operators place the workpiece and press start — the machine automatically executes squeeze, discharge, hold and release. Suitable for contract manufacturers and hardware suppliers running mixed production schedules.
How CD Projection Welding Works
| Step 1 | Step 2 | Step 3 | Step 4 | Step 5 |
|---|---|---|---|---|
| Capacitor Charging | Workpiece Positioning | Electrode Pressing | CD Pulse Discharge | Hold & Release |
The complete welding cycle finishes in 10-50ms. The operator manually loads the workpiece and initiates the program. All subsequent steps — squeeze, discharge, hold, off — are automatic.
Technical Specifications
| Parameter | DN(B)-100 | DN(B)-160 | DN(B)-200 | DN(B)-250 |
|---|---|---|---|---|
| Rated Power (KVA) | 100 | 160 | 200 | 250 |
| Power Input | 3-Phase AC 380V | |||
| Max. Short Circuit Current (KA) | 30 | 35 | 40 | 45 |
| Duty Cycle (%) | 50 | |||
| Max. Electrode Force (N) | 6000 | 6000 | 10000 | 15000 |
| Electrode Length (mm) | 450 | 500 | ||
| Working Stroke (mm) | 80 | |||
| Cooling Water (L/min) | 20 | |||
| Max. Welding Capacity (mm) | 3.0+3.0 | 4.0+4.0 | 5.0+5.0 | 6.0+6.0 |
Professional Manufacturing Capability
Xinwei Welding Technology Co., Ltd. operates an 18,000 square meter manufacturing facility with a dedicated R&D team of over 20 engineers. ISO 9001, CE and RoHS certified. Serving customers in more than 30 countries worldwide.
As a resistance welding specialist, Xinwei designs and manufactures capacitor discharge projection welders with customized electrodes and fixtures for specific fastener applications. Every machine undergoes welding cycle verification and parameter optimization before shipment.
Why Choose Xinwei CD Projection Welding Machine
| Feature | Your Benefit |
|---|---|
| Capacitor Discharge Technology | 10-50ms weld cycle preserves coating integrity on galvanized materials |
| Projection + Spot Welding | One machine handles both nut projection welding and sheet metal spot welding |
| Manual Load / Auto Weld Mode | Simple operation, reduced dependency on skilled welders |
| Grid-Friendly Charging | No instantaneous current surge, stable workshop voltage |
| Four Model Options | 100 to 250KVA, welding capacity from 3.0+3.0mm to 6.0+6.0mm |
| 12-Month Warranty | Remote support, spare parts and optional on-site training |
Free CD Welding Sample Test
Send us your nuts, screws, bolts and sheet metal samples. Our welding engineers will test the optimal capacitor discharge parameters on your actual materials and provide a detailed report including weld nugget inspection, pull-out test results and recommended machine configuration — free of charge.
Send your fastener samples for a free CD welding test
Welding Quality Verification
✓ Weld Nugget Cross-Section Inspection Per Machine
✓ Pull-Out Force Testing on Welded Fastener Samples
✓ Surface Coating Integrity Check for Galvanized Materials
✓ ISO 9001:2015 Certified Quality Management System
✓ CE and RoHS Compliance for International Markets
Frequently Asked Questions
Q: How is capacitor discharge welding different from AC resistance welding?
Capacitor discharge welding stores energy in a capacitor bank and releases it in a single 10-50ms pulse. This is significantly faster than AC welding (200-500ms). The short pulse produces less heat on the workpiece, preserving coatings on galvanized materials, and draws power gradually from the grid rather than creating a high-current surge.
Q: Can this machine weld coated or galvanized fasteners?
Yes. The short CD discharge pulse (10-50ms) generates minimal heat input at the weld zone, making it particularly suitable for galvanized nuts, zinc-coated screws and other surface-treated fasteners where coating preservation is critical.
Q: What materials and fastener types are compatible?
The machine handles carbon steel, stainless steel, aluminum and galvanized materials. It supports projection welding of nuts, screws, bolts and studs, as well as standard spot welding of metal sheets up to the rated capacity of each model (3.0+3.0mm to 6.0+6.0mm depending on model).
Q: Does capacitor discharge welding reduce electricity costs?
Yes. Unlike AC welders that draw high current continuously, the CD system charges capacitors at a lower power level between welds and only discharges during the brief welding pulse. This eliminates idle transformer losses, avoids workshop voltage drops and can reduce electricity costs for facilities with time-of-use pricing.
Get Your CD Fastener Welding Configuration
Tell us your fastener type, material, sheet thickness and production volume. Our engineers will recommend the right DN model and design the electrode configuration for your application.
12-Month Warranty | Free Welding Test | Factory Direct from Xinwei
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.