UNS T51606 Case Hardening Steel Round Bar Rods

Product Description

1. Material Identification and Cross References

• UNS Designation: UNS T51606

• AISI/SAE Designation: AISI P6 (P-6 Tool Steel)

• Trade Name: Carpenter 158 / CarTech No. 158 / C-158

• DIN / WNr Standard: DIN 1.2735 / DIN 15NiCr14

• EN Standard: EN ISO 4957 / EN 10084

• US Specifications: AMS 6265, ASTM A646, QQ-S-624C

2. Chemical Composition (Nominal Mass Percent)

• Carbon: 0.10

• Nickel: 3.50

• Chromium: 1.50

• Manganese: 0.50

• Silicon: 0.30

• Iron: Balance

3. Physical Properties

• Density: 7.87 grams per cubic centimeter

• Specific Gravity: 7.87

• Modulus of Elasticity: 207 GPa

• Modulus of Rigidity: 81.4 GPa

• Coefficient of Thermal Expansion: 11.88 x 10^-6 per degree Celsius (20 to 100 degrees Celsius)

4. Mechanical Properties

• Annealed Supply Hardness: Maximum 229 HBW (Brinell)

• Core Tensile Strength: 1100 to 1300 MPa

• Core Yield Strength (0.2% offset): Minimum 800 MPa

• Core Impact Resistance (Charpy-V): High core toughness and shock resistance

• Achievable Surface Hardness: 60 to 64 HRC (after carburizing, quenching, and tempering)

5. Heat Treatment Parameters

• Forging: 1100 to 1150 degrees Celsius (Do not forge below 900 degrees Celsius)

• Soft Annealing: 650 to 700 degrees Celsius followed by slow furnace cooling

• Stress Relieving: 590 to 650 degrees Celsius

• Carburizing Temperature: 870 to 925 degrees Celsius (Target case carbon depth: 0.80% to 1.00%)

• Quenching / Hardening: 775 to 815 degrees Celsius in oil

• Sub-Zero Treatment: -73 degrees Celsius for 1 hour to transform retained austenite

• Tempering: 150 to 200 degrees Celsius for stress relief and maximum wear resistance

6. Manufacturing and Supply Specifications

• Available Formats: Hot Rolled Round Bars, Cold Drawn Rods, Forged Round Shafts, Centerless Ground Bars

• Diameter Range: 6 mm to 800 mm (Standard Stocking: 12 mm to 400 mm)

• Delivery Condition: Soft Annealed (+A) or Normalized

• Surface Finishes: Black As-Rolled, Turn-Peeled, Centerless Ground, Bright Polished

• Machinability Rating: Approximately 40 percent relative to AISI B1112 free-cutting steel

7. Primary Industrial Applications

• Heavy-duty drive gears, transmission pinions, spline shafts, and bevel gears

• Firearms components including high-stress bolts, receivers, and barrel extensions

• Plastic injection molds and zinc die-casting dies requiring high core strength

• Pneumatic hammer components, rock drill assemblies, and heavy-duty wrist pins

• High-tensile industrial fasteners, heavy clamping hardware, and structural pins