Maraging 300
Maraging 300 is the most widely used grade in the maraging family. It provides an exceptional nominal yield strength of 300,000 psi (2068 MPa) while maintaining sufficient ductility for complex aerospace applications. It is an 18% nickel, cobalt-molybdenum steel.
- Common Forms: Round Bar, Forged Billet, Plate.
- Key Feature: Ideal balance of extreme strength and functional ductility.
- Heat Treatment: Low-temperature aging with minimal distortion.
- Purity: Typically supplied as Double Melted (VIM-VAR).
Maraging 300 is the "Gold Standard" for ultra-high-strength applications. While harder than Maraging 250, it retains enough fracture toughness to be used in critical rotating components and structural aerospace parts. Its unique chemistry allows it to be machined in the annealed condition and then hardened with virtually no dimensional change.
Ultra-High Strength
Achieves tensile strengths exceeding 300 ksi, significantly higher than conventional high-strength steels like 4340 or 300M.
Dimensional Stability
The aging process (900°F) causes negligible size change, allowing parts to be finished to tolerance before heat treatment.
Nitriding Capability
Can be nitrided to achieving high surface hardness for wear resistance, useful in gear and transmission applications.
| Element | Content (%) |
|---|---|
| Nickel (Ni) | 18.0 - 19.0 |
| Cobalt (Co) | 8.5 - 9.5 |
| Molybdenum (Mo) | 4.6 - 5.2 |
| Titanium (Ti) | 0.5 - 0.8 |
| Aluminum (Al) | 0.05 - 0.15 |
| Iron (Fe) | Balance |
*Note: Increased Titanium content vs. Maraging 250 provides the higher strength levels.
| Product Form | Standards (AMS / ASTM / MIL) |
|---|---|
| Bar, Forgings | AMS 6514 |
| Plate, Sheet, Strip | AMS 6521 |
| Military Spec | MIL-S-46850 Type IV |
| Chemical Comp | ASTM A538 (Grade B) |
As the "Gold Standard" of the maraging steel family, we supply Maraging 300 in a wide array of premium, double vacuum melted (VIM-VAR) forms, specifically engineered to support the critical demands of the aerospace, motorsport, and defense industries.
Round Bar & Billet
The most requested form. Supplied in the solution annealed condition, ready for CNC machining into ultra-high-strength motorsport driveshafts, gears, and aerospace landing gear components.
Plate & Sheet
High-strength flat stock utilized for fabricating lightweight, extremely durable tactical missile skins, solid rocket motor cases, and advanced defensive armor.
Forgings & Seamless Rings
Custom forged blocks and ultra-high-strength rolled rings forming the core structure of specialized gas centrifuges, industrial heavy-duty couplings, and rotating engine components.
Wire & Welding Filler
Specialized wire forms utilized for manufacturing extreme-duty torsion springs and providing matching filler metal to ensure full-strength maraging steel weldments.
| Property | Typical Values (Room Temp) |
|---|---|
| Yield Strength (0.2% Offset) | 290 - 300 ksi (2000 - 2068 MPa) |
| Ultimate Tensile Strength | 300 - 315 ksi (2068 - 2172 MPa) |
| Elongation | 7 - 10 % |
| Reduction of Area | 40 - 50 % |
| Hardness (Rockwell C) | 53 - 55 HRC |
| Fracture Toughness (KIC) | ~60 ksi√in |
*Note: Properties achieved after aging at 900°F (482°C) for 3-6 hours.
Aerospace Structural Components
Landing gear components, flexure shafts, and structural members requiring high strength-to-weight ratios.
Motorsports
High-performance racing crankshafts, gears, and connecting rods subjected to extreme cyclic loading.
High Speed Rotors
Industrial gas centrifuges and flywheel energy storage systems requiring dimensional integrity at high RPMs.
Rocket Motor Cases
Pressure vessels and casings for solid-fuel propulsion systems.
Need Maraging 300?
We supply premium quality Maraging 300 (VIM-VAR) in a wide range of bar sizes and plates. Material is fully certified to AMS and MIL specifications.
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