PRECISION ALLOY

SUNNING STEEL LIMITED supplies a complete programme of precision alloys in strip, bright bar, wire, and ring form, covering the four families most specified by European engineering buyers:

• Soft magnetic grades: 1J50, 1J79, 1J22
• Controlled-expansion grades: 4J29, 4J36
• Precision resistance grades: 6J22, 6J23, 6J40
• Heating grade: Cr20Ni80

Precision alloys serve as critical materials with applications across a wide range of sectors, including electronics and electrical engineering, consumer electronics, precision instrumentation, information and communications, metal-to-glass/ceramic sealing, automatic control, automotive, aerospace, and nuclear power.

Precision strip is produced down to a minimum thickness of 0.005 mm with a maximum width of 450 mm, and thickness tolerance can be held to ±0.5 µm. The dimensional control required for transformer cores, magnetic shielding, hermetic seals, precision resistors, and heating elements. Bright bar, wire and rings complete the range for machining, winding and fabrication.

Application

• Electronics & Electrical: Sensor cores, choke cores, sensors, specialty transformers, solenoid valves, magnetic shielding, wave springs, etc.
• Consumer Electronics: Mobile phone display panels and mid-frames, electronic connectors, wireless earphones, 5G base station components, etc.
• Automatic Control: Signal amplifiers, sensors, switches
• Precision Instruments: Pressure-sensing diaphragms
• Information & Communication: Fiber optic connectors, cable shielding

Advantages

1. Excellent physical properties of the product
2. Accurate chemical composition of materials, low inclusion content, and high purity of materials
3. High dimensional accuracy, good strip shape, high flatness, and excellent surface quality indicators
4. The steel strip coil is heavy; the maximum coil weight is 2800kg

Specifications-Table

Comparison Table of Precision Alloy Grades
Alloy Type	Grade	Comparable Grades	Cold-Rolled Strip	Cold-Drawn Wire	Forged & Rolled Bar
Soft Magnetic Alloy	1J50		✓		✓
	1J79	Permalloy	✓	✓	✓
	1J22	Hiperco 50	✓		✓
Controlled-Expansion Alloy	4J29	Covar	✓	✓	✓
	4J36	Invar	✓	✓	✓
Precision Resistance Alloy	6J22	Karma	✓
	6J23	Evanohm	✓
	6J40	Constantan	✓
Heating Alloy	Cr20Ni80		✓

Precision Alloy Product Specifications
Product Type	Thickness/mm	Width/mm	Length/mm	Remarks
Hot Rolled Plate	6–100	100–400	100–3000
Hot Rolled Strip	3–6	100–450	100–25000
Bar	Φ10–Φ150	—	100–4000
Cold Rolled Plate	0.9–3.0	300–1000	100–3000
Cold Rolled Strip	0.1–2.0	200–450	—	Coil
Cold Rolled Thin Strip	0.03–0.1	200–450	—	Coil
Foil	0.005–0.03	≤100	—	Coil
Wire	Φ3–Φ10	—	—	Coil

FAQs