SS 1550 Alloy Steel Bar 1550 Round Bars 1550 Rods

Product Description

SS 1550 (Swedish Standard) is a high-quality medium-carbon structural steel. Under the Swedish steel numbering system, the "15" prefix denotes unalloyed or low-alloy structural steels, and "50" indicates the carbon content level.

This grade is nearly identical to the European C35 or C40 grades and is widely used throughout Scandinavia for mechanical engineering applications where a balance of strength, ductility, and machinability is required.

1. Chemical Composition

SS 1550 is a non-alloy steel with a carbon content of approximately 0.35%.

2. Mechanical Properties

Its performance is typically measured in the Normalized (+N) or Quenched and Tempered (+QT) state.

3. Key Technical Characteristics

• Surface Hardening: SS 1550 is very well-suited for flame or induction hardening. This process allows for a high-wear surface (up to 45–50 HRC) while keeping the core tough and resistant to impact.

• Machinability: It has excellent machining properties. It is a favorite for high-speed turning and milling because it provides a good surface finish and predictable tool life.

• Weldability: Fair. It is more weldable than SS 1650 (C45), but preheating to approximately 150°C is still recommended for thicker sections to avoid cold cracking in the heat-affected zone.

• Ductility: It offers better impact resistance and elongation than higher carbon grades, making it safer for parts subjected to shock or vibration.

4. Global Equivalents

If you are sourcing internationally, SS 1550 corresponds to these common standards:

5. Common Applications

SS 1550 round bars and rods are typically found in the automotive, agricultural, and general machinery sectors:

• Shafts & Spindles: Drive shafts, pump shafts, and axle journals.

• Fasteners: High-quality bolts, studs, and specialized tie rods.

• Mechanical Parts: Levers, connecting rods, spacers, and hubs.

• Gears: Low-to-medium load gears and racks (often induction hardened).

Stock & Availability

• Round Bars: Available in a wide range of diameters, from 10mm to 350mm+.

• Precision Rods: Available as cold-drawn or centerless ground for high-precision CNC work (h9 tolerances).

• Condition: Typically supplied in Normalized (+N) or Untreated condition.