raw material advantages: high-quality electrical pure iron guarantee

We insist on providing Relay Core solutions: Automotive Relay Core, Latching Relay Iron Core, Grooved Core for AC Relay, EV Relay Core and raw materials (TD4C) produced by large Chinese state-owned enterprises, which have significant characteristic advantages:

Relay Cores

Performance indicators	TD4C standard value	Common materials in the industry
Iron content	≥99.8%	≤99.5%
Coercive force (Hc)	≤32A/m	≥50A/m
Magnetic permeability (μm)	≥5000	≤3000
Hardness (HV)	80-100	120-150
Grain size level	8 level	6 level

Material core advantages:
(1). Ultra-high purity ensures excellent soft magnetic properties
(2). Low coercive force achieves a fast magnetization/demagnetization response
(3). Uniform grain structure ensures magnetic performance consistency
(4). Moderate hardness is conducive to cold heading

Relay Core Family

Precision Cold Heading Production Process

1. Tungsten steel alloy mold manufacturing
Using YG15 tungsten steel material, hardness reaches HRA90
The mold life can reach more than 1 million times
The cavity accuracy is controlled at ±0.005mm

2. One mold, three-punch cold heading process

Process	Processing content	Precision control
First punch	Preforming	±0.03mm
Second punch	Finishing shape	±0.02mm
Third punch	Final forming and chamfering	±0.01mm

Process advantages:
Production efficiency increased by 40%
The material utilization rate reached 98%
Relay core cold heading consistency significantly improved

3. Key process control points

(1). Dimension control
Daily spot checks using a three-coordinate measuring machine
Critical dimensions CPK≥1.67

(2). Surface quality control
Surface roughness Ra≤0.8μm
No visible cracks or burrs

(3). Weight control
Single piece weight tolerance ±0.5%
Automatic weighing and sorting system

Production Processes and Types of Iron Core

post-processing process and quality control

1. Heat treatment demagnetization process
Using hydrogen protection continuous annealing furnace
Temperature control: 850±5℃
Coercive force after annealing ≤25A/m
Magnetic permeability increased by more than 30%

2. Nickel plating surface treatment

Parameter	Standard value	Detection method
Coating thickness	5-8μm	X-ray thickness gauge
Coating bonding	No peeling	Thermal shock test
Salt spray test	≥72h no rust	Neutral salt spray test
Surface resistance	≤0.5mΩ	Four-probe method

3. 100% CCD full inspection
- Inspection items: size, appearance, coating
- Inspection accuracy: 0.01mm
- Automatic rejection rate of defective Straight Coil Cores: 100%
- Inspection speed: 300pcs/min

Iron Core Details Show

Quality assurance system

1. Process quality control
IQC incoming material inspection: magnetic property test of each batch of raw materials
IPQC process inspection: hourly size sampling
OQC factory inspection: full performance test

2. List of testing equipment
1. Magnetic property tester
2. Three-coordinate measuring machine
3. Metallographic microscope
4. X-ray coating thickness gauge
5. Automatic CCD detection sorting machine

3. Industry certification
ISO9001:2015 quality management system
IATF16949 automotive industry certification

With 20 years of experience in focusing on Relay Iron Core manufacturing, we have built a complete quality assurance system from electrical pure iron core raw material selection to cold heading core precision molding, and then to strict process quality control. Our core DT4C Iron Cores have won the long-term trust of global customers with excellent magnetic properties, precise dimensional control, and stable quality performance.

Relay lron Cores Cold Heading Production Dust-free Workshop

Company Profile and Core Advantages

As China's leading relay core professional manufacturer, we have more than 20 years of rich experience in cold heading core production. Our Coil Core for Electromagnetic relays are widely used in power relays, automotive relays, high-voltage DC relays, power magnetic latching relays, signal relays, and industrial relays, providing high-precision and high-consistency core magnetic components for the global relay industry.

1. Quality control system for the entire industry chain
Implement full quality control from raw material procurement to finished product packaging
Own an independent mold workshop, specializing in the production of tungsten steel alloy cold-heading molds
Introduce precision cold heading equipment imported from Taiwan to ensure dimensional accuracy of ±0.01mm

2. Professional production process
Adopt the "one mold three punches" advanced cold heading process
Original heat treatment demagnetization process
Fully automatic nickel plating production line to ensure surface treatment consistency

3. Strict testing standards
100% CCD full inspection to ensure zero defects before leaving the factory
Magnetic performance testing equipment to ensure that electromagnetic parameters meet the standards
Passed IATF16949 automotive industry quality management system certification

Application of relay core in various relays