1. Overview
C75S belongs to the family of high carbon spring steels (C67S, C70S, C75S, C80, C85S, C95S), widely recognized for its excellent hardness, tensile strength, and elasticity after proper heat treatment.
Jiaxiao MTC manufactures C75S high carbon steel strips in both cold-rolled annealed et hardened and tempered conditions, ensuring high precision in thickness, width, and flatness tolerances.
2. Chemical Composition and Equivalent Grades
| Standard | Equivalent Grades | C (%) | Mn (%) | P max | S max | Si (%) |
|---|---|---|---|---|---|---|
| DIN | CK75 | 0.72–0.80 | 0.50–0.80 | ≤0.035 | ≤0.035 | 0.17–0.37 |
The high carbon content (around 0.75%) allows C75S steel to achieve excellent hardness after hardening and tempering, while manganese and silicon enhance its strength and toughness.
Equivalent international grades include:
- AISI 1075 (USA)
- BS CS75 (UK)
- JIS SUP4 (Japan)
- EN C75 (Europe)
3. Production Process
C75S strips from Jiaxiao MTC are manufactured under strict quality control:
- Hot Rolled Steel Coils: Sourced from ISO-certified suppliers.
- Acid Pickling: Removes oxide scale and improves surface quality.
- Cold Rolling: Reduces thickness and enhances dimensional accuracy.
- Annealing (optional): Softens material and increases ductility.
- Hardening & Tempering: Heat treatment for strength and elasticity.
- Slitting, Edge Treatment, and Polishing: Achieve the required width, edge shape (slit, square, or rounded), and surface finish (natural, blue, yellow, polished).
Jiaxiao MTC’s advanced facilities — including 4-high reversing cold rolling mills, continuous annealing furnaces, et precision levelling equipment — guarantee consistent mechanical properties and excellent surface flatness.
4. Mechanical Properties
| Condition | Hardness | Tensile Strength (Approx.) | Typical Surface | Edge Type |
|---|---|---|---|---|
| Annealed | ≤180 HV | 579 N/mm² | Bright or polished | Slit / Mill |
| Hardened & Tempered | 30–55 HRC | up to 1700 N/mm² | Blue, Yellow, or Polished | Rounded / Square |
C75S strips can be customized according to application requirements in both annealed et tempered states, with thickness ranging from 0.1mm–5.0mm and width up to 500mm.
5. Applications
Due to its balance between strength and flexibility, C75S is used in a wide variety of mechanical and industrial fields:
- Spring Manufacturing:
Ideal for flat springs, shutter springs, and precision coil springs where resilience and shape memory are essential. - Saw Blade Production:
Commonly used for band saws, hacksaws, and circular saw blades due to high wear resistance and edge retention. - Hand Tools:
Applied in trowels, scrapers, putty knives, and other construction tools requiring durable, flexible steel. - Automotive Components:
Suitable for clutch washers, spring seats, and clips that undergo repeated mechanical stress.
6. Quality Control and Tolerances
Jiaxiao MTC ensures strict dimensional and mechanical consistency.
Thickness tolerance: ±0.015mm–±0.070mm depending on range.
Width tolerance: ±0.20mm–±0.80mm.
Flatness et straightness are verified under class R1–R4 tolerances to guarantee uniform performance during stamping or coiling.
Each coil undergoes:
- Chemical composition analysis
- Hardness and tensile strength testing
- Visual and surface inspection
before being packed in anti-rust paper, plastic film, and sealed for sea-worthy export.
7. Advantages of Jiaxiao MTC’s C75S Strips
- Precise control of hardness and elasticity through heat treatment
- Excellent surface quality and dimensional accuracy
- Customizable thickness, width, and edge profiles
- Proven performance in shutter springs and saw blade production
- 20+ years of manufacturing experience for industrial-grade steel strips
8. Packaging and Delivery
Each coil is lightly oiled, wrapped in plastic film and anti-rust paper, and securely packed into standard 20ft containers.
Customized packaging and labeling are available according to buyer specifications.
9. About Jiaxiao MTC
Guangzhou Jiaxiao Material Technology Co., Ltée.
is a professional manufacturer of high carbon steel strips, alloy steel strips, et bandes d'acier inoxydable in both hardened & tempered et cold-rolled annealed conditions.
With a 25,000 m² production area, over 100 skilled employees, and advanced rolling, recuit, and polishing equipment, Jiaxiao MTC supplies more than 15,000 tons per year to global industries including springs, blades, automotive parts, and tools.
