4140 Steel Build Platform - AMS 6395 - ASTM A829 - UNS G41400

4140 steel plate (AMS 6395) is an aircraft-quality, chromium-molybdenum alloy steel prized for its exceptional strength, toughness, and hardenability. Engineered for demanding environments, this grade offers superior resistance to fatigue and wear, making it a reliable choice for structural and mechanical components that require durability under stress. Its alloy composition ensures consistent performance in applications where precision and resilience are critical.

Supplied in normalized or heat-treated conditions, 4140 steel delivers an excellent balance of strength, ductility, and machinability, allowing for efficient fabrication and finishing. It can be further heat-treated to achieve hardness levels up to 50 HRC in thinner sections, providing versatility for parts that demand high hardness without sacrificing toughness. This combination of properties makes 4140 ideal for aerospace, defense, oil and gas, and other industries where performance and reliability are non-negotiable.

Advanced Inventory Size Ranges for 4140

Type	Size Range	Specifications	Get a Quote
Build Platforms	0.500" - 5.000"	AMS 6395, ASTM A829, UNS G41400	Get a Quote

Ideal for Additive Manufacturing Build Platforms

In Powder Bed Fusion (PBF) systems, platform rigidity and thermal stability are critical for maintaining part integrity and dimensional accuracy. 4140 steel offers exceptional strength and toughness, ensuring a stable surface through repeated thermal cycles and heavy build loads. Its excellent hardenability and wear resistance make it a reliable choice for demanding environments where precision and durability are essential—such as aerospace, defense, energy, and industrial applications.

Why Choose United Performance Metals?

At United Performance Metals, we manufacture 4140 Steel Build Platforms to exacting standards, offering:

Superior Strength & Stability: Maintains flatness and structural integrity under high thermal and mechanical stresses.
Excellent Machinability & Weldability: Enables precision finishing for optimal powder bed performance.
Heat-Treatable for Enhanced Hardness: Achieve hardness levels up to 50 HRC for extended platform life.
Custom Sizes: Available to fit your specific PBF machine requirements.

Other industry standards we comply with:

Common Trade Names

AISI 4140, SAE 4140

Industry Applications for 4140

Landing Gear Components
Structural Fittings
Drill Collars
Turbine Shafts
Machine Bases

Chemical Composition

	Element	Percent by Weight Min	Percent by Weight Max
C	Carbon	0.38	0.43
Mn	Maganese	0.75	1.00
Si	Silicon	0.15	0.35
Cr	Chromium	0.80	1.10
Mo	Molybdenum	0.15	0.25
P	Phosphorous		0.035
S	Sulfur		0.040
Fe	Iron	Balance

Physical Properties

Property	Values
Density	7.85 g/cm³
Modulus of Elasticity	190–210 GPa
Thermal Expansion	12.2 μm/m-°C
Thermal Conductivity	~42 W/m·K
Poisson's Ratio	0.27–0.30

Mechanical Properties

Condition	Tensile (MPa)	Yield (MPa)	Hardness
Annealed	655–785	415–585	~197 HB
Normalized	710–850	470–630	~229 HB
Quenched & Tempered	835–1080	655–900	45–50 HRC

Additional Info

A Brief History of 4140 Steel

4140 steel emerged in the early 20th century as alloy steels became increasingly important to heavy industry. As steelmaking advanced beyond simple carbon steels, metallurgists began adding chromium and molybdenum to improve strength, toughness, and hardenability.

By the 1920s–1930s, the automotive, oil, and machinery sectors demanded steels that could handle higher loads, deeper hardening, and more severe service conditions. This led to the development of the 41xx family of chromium‑molybdenum steels and 4140 becoming the most widely used grade.

How 4140 was Developed

Early carbon steels lacked the strength and heat‑treat response needed for rapidly growing industries. Researchers discovered that adding chromium improved wear resistance and hardenability, and molybdenum improved high-temperature strength and reduced brittleness. These discoveries formed the foundation of the 41xx series. 4140 was engineered to harden deeply and uniformly, maintain toughness after quenching, and resist fatigue and shock loads. These traits made it ideal for demanding mechanical applications.

Early Applications of 4140

As soon as it became commercially available, 4140 was adopted in industries that needed strong, durable, heat‑treatable components. Common early applications included automotive parts, oil & gas equipment, industrial machinery, forgings, and firearms.

How 4140 is Used Today

4140 remains one of the most versatile and widely used alloy steels in modern manufacturing.

Industrial: Shafts, spindles, arbors, gears, sprockets, couplings, power-transmission components, hydraulic cylinder rods
Oil & Gas: Drill collars, tool joints, frac equipment, high-pressure fittings
Automotive: Axles and drive shafts, suspension components, high-strength fasteners, transmission parts
Tooling & Die: Mandrels, dies, fixtures, high-strength jigs
Defense: Barrels, receivers, high-stress structural parts

Your Trusted Supplier of 4140 Steel

UPM Advanced Solutions supplies 4140 steel build platforms in sizes 0.500" - 5.000". These build platforms are ideal for Powder Bed Fusion (PBF) systems, offering exceptional strength, toughness, and a stable surface for repeated thermal cycles and heavy build loads.

Product FAQs

4140 demonstrates high tensile and yield strength, excellent toughness and fatigue resistance, good wear resistance, and deep, uniform hardenability. 4140 also is good for machining in the annealed condition.

4140 has a reputation for being a workhorse material for PBF (Powder Bed Fusion) build plates because its mechanical and thermal behavior aligns extremely well with what a build plate must endure. When you break down the demands of PBF—rapid heating, steep thermal gradients, repeated stress cycles, and the need for predictable flatness—4140 checks the right boxes in a way that many steels don’t.