ISO C35E4 Alloy Steel Bar C35E4 Round Bars C35 Rods

Product Description

ISO C35E4 (often simply referred to as C35 in broader contexts) is a high-quality non-alloy medium-carbon structural steel. Under the ISO 683-1 standard, the "E4" suffix typically denotes a specific control over residual elements and sulfur content, often intended for induction hardening or specific quenching requirements to ensure high purity and consistent mechanical behavior.

1. Chemical Composition

C35E4 is a "clean" carbon steel, balanced to provide better toughness and ductility than higher carbon grades like C45.

2. Mechanical Properties

The performance of C35E4 depends on its heat treatment state. It is most commonly used in the Normalized (+N) or Quenched and Tempered (+QT) condition.

3. Key Technical Characteristics

• Hardenability: Being a medium-carbon steel, it has limited through-hardenability. It is best suited for parts with smaller cross-sections or for surface (induction/flame) hardening.

• Weldability:Fair. Preheating is recommended for sections thicker than 20mm to prevent cracking in the heat-affected zone (HAZ).

• Machinability:Excellent. C35E4 is favored in high-volume CNC manufacturing because it chips well and results in a high-quality surface finish.

• Ductility: It offers a higher degree of "forgiveness" and toughness compared to C45, making it less prone to brittle fracture under sudden loads.

4. Global Equivalents

C35 is a universal grade with very close matches across all major international standards:

5. Common Applications

C35E4 round bars and rods are typically used for components requiring moderate strength and high fatigue resistance:

• Automotive: Levers, connecting rods, and crankshafts for small engines.

• Fasteners: Medium-strength bolts, studs, and nuts (Class 5.8 or 6.8).

• General Engineering: Simple axles, drive shafts, spacers, and keyed shafts.

• Agricultural: Pivot pins, bushings, and light-duty structural supports.

Available Supply Forms

• Round Bars: Available in hot-rolled (black), peeled, or ground finishes.

• Precision Rods: Often supplied in h9 or h11 tolerances for direct use in lathes.

• Standard Condition: Usually stocked in Normalized (+N) or Untreated state.