Carbon steel is an iron-carbon alloy. Based on carbon content it is divided into:
Low-carbon steel (C < 0.25%): also called mild steel, offering excellent ductility and toughness and easy forming.
Medium-carbon steel (0.25% <= C <= 0.6%): balances strength and toughness while remaining machinable.
High-carbon steel (C > 0.6%): provides the greatest hardness and strength but lower toughness/ductility, suited to high-strength, wear-resistant tools and components.
1. Strength and toughness depend on carbon content-low-carbon grades emphasize toughness, while medium-carbon grades balance strength with ductility.
2. Formability: carbon steels can be hot- or cold-worked, welded, cut, forged, and cast with ease, especially low-carbon grades.
3. Wear resistance: medium- and high-carbon alloys tolerate frictional wear, making them suitable for sliding parts.
4. Cost efficiency: compared with alloy steels they are economical and made from readily available feedstock.
1. Mechanical parts such as gears, shafts, bolts, and connecting rods that require dependable strength and toughness.
2. Structural members-including building frames, bridge components, and pressure vessels-that demand load-bearing capacity and durability.
3. Automotive structures such as frames, body components, and engine parts that rely on both strength and wear resistance.
High carbon content is the key performance driver-the greater the carbon, the higher the attainable hardness and strength.
High hardness and wear resistance achieved through quenching and tempering.
Limited toughness: the high carbon level makes the steel relatively brittle.
Low hardenability compared with alloy tool steels, so only small sections through-harden in water or oil.
Poor red hardness: hardness drops rapidly above roughly 250 deg C.
Cost-effective because expensive alloy elements are not required.
Cutting and measuring tools such as turning tools, planers, milling cutters, drills, gauges, and plugs.
Cold-forming dies including blanking dies, thread rolling plates, and wire-drawing dies.
Hand tools-hammers, screwdriver bits, reamers, chisels, saw blades, etc.
Mechanical parts that need hardness and wear resistance, such as springs or certain automotive components.
High elastic limit: large deflection is possible without permanent set, ensuring full spring recovery.
High fatigue strength that tolerates long-term cyclic loading without cracking.
Stress-relaxation resistance so spring force does not decay quickly under repeated load.
High tensile/yield strength paired with adequate toughness to avoid brittle failure.
Strict cleanliness requirements-low inclusions and carbides keep performance stable.
Excellent surface quality with controlled defects and decarburization to protect fatigue life.
Automotive: suspension and chassis springs.
Rail vehicles: shock-absorbing and suspension springs.
Industrial machinery: springs in presses, actuators, and general equipment.
Consumer goods: mattress and furniture springs.
Precision instruments: miniature and calibration springs.
Musical instruments: e.g., piano wire springs and other sound mechanisms.
Very high tensile strength so coils withstand large forces without breaking or taking a set.
Outstanding fatigue resistance for springs that operate under continuous cycling.
Superior surface quality with tightly controlled defects and decarburized layers to protect fatigue life.
Excellent winding/forming behavior during spring coiling.
Automotive: engine-valve, clutch, and brake springs.
Precision instruments requiring stable miniature springs.
General machinery and tooling spring assemblies.
Mattress support units and upholstery springs.
Electronics: contact springs and connectors.
Fitness equipment, hinges, seat supports, and other consumer hardware.
High tensile strength after cold drawing.
High hardness suited to load-bearing products.
Retains useful elasticity for springs and elastic members.
Simple manufacturing-cold drawing alone often achieves the required properties.
Cost-effective compression, extension, and torsion springs.
Wire mesh, fencing, and screens.
Construction reinforcement such as wire rope or rebar ties.
Mechanical parts that need strength and wear resistance.
Primarily carbon steel with silicon, manganese, phosphorus, and sulfur; exact chemistry follows the base grade (low/medium/high carbon).
High strength: tensile levels can approach 2,000 MPa after tempering.
High hardness: quenching forms a hard martensitic surface.
Tough core: retains ductility to resist brittle failure.
Fine grain structure: specialized heat treatment refines grains for improved performance.
Customizable: heat-treatment schedules can be tuned for specific strength/ductility targets.
High-performance springs, mechanical parts, and other components that must endure abrasion or high stresses.
Chromium (~0.5%-1.5%) boosts hardenability, hardness, and wear resistance.
Vanadium (~0.1%-0.3%) refines grains to raise toughness, strength, and fatigue resistance.
Carbon (~0.5%-0.6%) supplies the base hardness and strength.
High strength with useful toughness for impact- and stress-loaded parts.
Excellent wear resistance thanks to chromium carbides.
Great fatigue performance from vanadium grain refinement.
Good hardenability for uniform properties through thicker sections.
Better corrosion resistance than plain carbon steel (though not stainless).
Automotive suspension, valve, and other durable springs.
High-strength hand tools such as wrenches, sockets, and screwdrivers.
Mechanical parts including gears, shafts, and bolts subjected to heavy loads.
Automotive driveline and suspension components that require fatigue resistance.
Chromium (~0.5%-1.5%) raises hardenability, hardness, and wear resistance.
Molybdenum (~0.15%-0.5%) boosts hot strength, toughness, and resistance to temper embrittlement.
Carbon (~0.3%-0.5%) delivers the base strength after heat treatment.
High strength and toughness for shock- or stress-loaded parts.
Excellent hardenability so even thick sections harden uniformly.
Superior high-temperature performance-Mo maintains strength and stability at elevated temperatures.
Resists temper embrittlement, keeping toughness after heat treatment.
Good wear and fatigue resistance for components under repeated loads.
Automotive components such as crankshafts, connecting rods, gears, and drive shafts.
Pressure vessels, boiler tubes, and petrochemical piping operating in hot, high-pressure service.
Springs that demand fatigue strength and durability (suspension, valve, and actuator springs).
Hand tools, bolts, and fasteners that require strength and wear resistance.
Aerospace hardware exposed to extreme temperature and stress.
Chromium ~0.6%-1.0% for hardenability and wear resistance.
Silicon ~1.2%-2.8% to raise elastic limit, temper resistance, and fatigue strength.
Carbon ~0.5%-0.7% for base hardness/strength.
Manganese as a supplementary element to aid hardenability.
High elastic limit allowing large deflection without permanent set.
Outstanding fatigue resistance for springs under repeated loading.
Strong resistance to temper softening, so performance holds at elevated temperatures.
Great hardenability across larger cross-sections.
Improved corrosion resistance over plain carbon steels.
Automotive: suspension, valve, and clutch springs operating under high stress/temperature.
Industrial machinery: heavy-load and vibration-prone springs such as dampers.
Rail vehicles: suspension and buffer springs exposed to repeated impact.
Aerospace components that require reliable, durable springs.
Specialty springs for furnace doors, high-pressure valves, and other extreme environments.
Carbon (~0.5%-0.7%) guarantees base hardness and strength.
Silicon (~1.2%-2.8%) elevates elastic limit, temper resistance, and fatigue strength.
Manganese (~0.6%-1.2%) improves hardenability, strength, and toughness.
High elastic limit for large deflection without set.
Good fatigue resistance for long-term cyclic loading.
Improved hardenability across thicker sections.
Resists temper softening at service temperatures.
Balanced strength and toughness for medium-load service.
General spring production-automotive, damper, and machinery springs.
Automotive suspension/valve/clutch components.
Elastic members and structural parts in machinery (washers, buffers, etc.).
Railway suspension and buffer springs.
Agricultural machinery springs and wear parts.
Chromium 16%-26% supplies fundamental corrosion resistance.
Nickel 6%-22% stabilizes the austenitic structure and improves toughness and corrosion resistance.
Carbon kept very low (<0.08%) to avoid intergranular corrosion.
Additional elements such as Mo, N, or Mn may be added for pitting resistance or strength.
Excellent corrosion resistance in oxidizing, acidic, and saline environments.
Outstanding toughness and ductility even at low temperatures, with good formability.
Essentially nonmagnetic in the annealed condition (may become slightly magnetic after cold work).
Good weldability without post-weld heat treatment.
Cannot be hardened by heat treatment; strengthening relies on cold work.
Higher cost due to nickel content.
Food-processing and kitchen equipment-cookware, utensils, sanitary tanks.
Chemical processing vessels, piping, and storage tanks resistant to acids/alkalis.
Architectural trim such as facades, railings, and handrails for aesthetics and durability.
Medical devices and surgical instruments requiring biocompatibility and corrosion resistance.
Automotive exhaust systems and decorative trim.
Oil and gas piping, valves, and pumps operating in harsh conditions.
Springs requiring corrosion resistance in food or medical equipment (even though elasticity is lower than other stainless families).
Chromium 11.5%-18% provides baseline corrosion/oxidation resistance.
Carbon 0.1%-1.2% ensures hardenability.
Optional Ni/Mo/V additions tailor properties for special uses.
Heat-treatable to very high hardness and strength (HRC 50-60).
Moderate corrosion resistance versus austenitic grades.
Magnetic in both annealed and hardened conditions.
Limited weldability-preheat/postheat often required to prevent cracking.
Lower toughness, especially after hardening.
Cutting tools and blades (kitchen knives, surgical instruments, scissors).
Springs needing high strength with moderate corrosion resistance.
Wear components such as bearings, gears, bolts, and nuts.
Hand tools and molds that must resist wear.
Aerospace parts like turbine blades and structural components.
Oil and gas valves, pumps, and hardware used in corrosive service.
Chromium about 12%-17% for corrosion and oxidation resistance.
Nickel about 3%-9% to stabilize the (semi-)austenitic matrix and enhance toughness/corrosion resistance.
Copper, aluminum, titanium, niobium, etc., which form strengthening precipitates (Cu, Ni3Al, Ni3Ti) during aging.
Carbon held low (<0.07%) to maintain weldability and corrosion resistance.
Very high strength and hardness after aging, rivaling high-strength alloy steels.
Better corrosion resistance than martensitic stainless steels.
Maintains toughness even at elevated strength levels.
Easy forming/machining in the solution-treated condition; strength develops after aging.
Good weldability because of low carbon; aging after welding restores strength.
Properties are tunable via aging temperature and time to meet different requirements.
Aerospace structures, turbine parts, and fasteners requiring high strength, corrosion resistance, and low weight.
Oil and gas high-pressure valves, pump parts, and pipe fittings operating in corrosive, high-stress service.
Chemical-processing hardware such as reactors and agitator components.
Medical instruments and orthopedic implants needing high strength and biocompatibility.
Springs for precision instruments and valves where both strength and corrosion resistance are critical.
Nuclear-industry components that must survive extreme environments.
Premium products (e.g., golf clubs, performance sporting goods) demanding high strength and low weight.
Nickel (Ni): roughly 17%-19%; the primary alloying element that forms a low-carbon martensitic structure and boosts toughness.
Cobalt (Co): about 8%-12%; accelerates precipitation during aging to raise strength.
Molybdenum (Mo): approximately 3%-5%; increases strength and toughness.
Titanium (Ti): around 0.3%-1.8%; forms Ni3Ti precipitates that dramatically elevate hardness and strength.
Aluminum (Al): added in certain grades to aid the aging response.
Carbon (C): kept extremely low (<0.03%), distinguishing maraging steels from conventional high-strength grades.
Ultra-high strength: Aging produces tensile strengths on the order of 1,400–2,400 MPa (or higher), ranking among the strongest steels available.
Excellent toughness: Despite the strength level, maraging steels retain good toughness and impact resistance—rare for ultra-strong alloys.
Dimensional stability: Minimal distortion during aging benefits precision components.
Good weldability: Very low carbon content enables welding; post-weld aging restores full strength.
Ease of machining prior to aging: Solution-annealed stock remains relatively soft for machining, forming, and welding; high strength develops only after aging.
Moderate corrosion resistance: Not stainless, yet adequate for general atmospheric service.
Higher cost: Nickel, cobalt, and molybdenum raise alloy cost relative to conventional steels.
Aerospace: Landing-gear structures, airframe members, and rocket-engine hardware that demand extreme strength-to-weight ratios.
Moldmaking: Plastic injection and die-casting molds requiring strength, toughness, and dimensional stability.
Precision tooling: High-accuracy tools, gauges, and precision mechanical components.
Military and defense: Artillery, missile, and armored-vehicle components that must withstand severe loads and impact.
Nuclear industry: Reactor parts that must remain stable in extreme conditions.
Oil and gas: Deep-sea drilling equipment, high-pressure valves, and pump components that endure heavy stresses.
Motorsports and high-performance vehicles: Drive shafts, transmission parts, and other lightweight yet ultra-strong components.
Primarily copper, nickel, and zinc with no actual silver content.
Appearance: bright silver-white, often mistaken for sterling silver.
Corrosion resistance: nickel content improves resistance to tarnish and chemicals.
Formability: easily cold-worked into intricate shapes.
Non-magnetic: useful near magnetic-sensitive electronics.
Home goods and flatware, plus numerous musical-instrument fittings.
Copper 95%-99% as the base.
Beryllium 0.5%-3% provides precipitation hardening.
Optional Co/Ni/Fe additions further tailor properties.
Ultra-high strength: aged tensile strength ~1200-1400 MPa, hardness ~HRC 38-42.
Outstanding elasticity and fatigue resistance for precision springs.
Good electrical/thermal conductivity (~15%-60% of pure copper) paired with strength.
Excellent corrosion resistance in atmosphere, seawater, and many chemicals.
Non-magnetic and spark-free-safe for sensitive or explosive environments.
Machinable in the annealed state; peak properties achieved after aging.
Higher cost and Be toxicity require careful handling controls.
High-performance springs, clips, diaphragms, and precision elastic components.
Electrical contacts, connectors, switches, relays, and sockets.
Non-sparking safety tools for oil, gas, chemical, and mining work.
Aerospace and instrumentation parts needing strength, reliability, and non-magnetic behavior.
Automotive connectors, sensors, and switchgear.
Medical instruments and implants thanks to corrosion resistance and biocompatibility.
Oil/gas valves, pump parts, and downhole tools requiring spark-free durability.
Moldmaking (injection or die-casting) where high hardness and thermal conductivity help productivity.
Copper (~85%-92%).
Tin (~4%-10%) for strength, hardness, and corrosion resistance.
Phosphorus (~0.01%-0.5%) acts as a deoxidizer and strengthens elasticity/fatigue performance.
Optional Pb/Zn/Fe additions fine-tune machinability or corrosion behavior.
Exceptional elasticity and fatigue life for dependable springs.
Strong corrosion resistance against seawater, atmosphere, and many chemicals.
Good wear and anti-galling behavior for bearings and sliding parts.
Decent electrical and thermal conductivity (though lower than pure copper).
Excellent cold-working, bending, stamping, and welding characteristics.
Non-magnetic, making it suitable for sensitive instrumentation.
Switch, contact, and instrument springs.
Electrical/ electronic connectors, relays, and terminals.
Bearings, bushings, and sliding components needing anti-galling behavior.
Cymbals, gongs, and other musical instruments for their tonal response.
Marine hardware that must endure seawater.
Chemical-processing valves, pumps, and piping.
Precision-measurement components requiring dimensional stability.
Primarily nickel and copper with aluminum and titanium for precipitation hardening.
High strength/hardness: yield strength about three times that of Monel 400 after aging.
Excellent corrosion resistance in seawater, many non-oxidizing acids, salts, and alkaline media.
Thermal stability: maintains strength up to ~649 deg C (1200 deg F).
Tough at low temperatures down to −200 deg F.
Non-magnetic below −200 deg F, ideal for magnetic-field environments.
Marine: propeller shafts, pump shafts, impellers.
Oil/gas: drilling equipment, downhole tools, valve components.
Nickel ~50%–55% for base high-temperature/corrosion performance.
Chromium ~17%–21% for oxidation and corrosion resistance.
Iron ~18%–19% for cost reduction/structural support.
Molybdenum + niobium ~4%–5% boost creep strength.
Titanium + aluminum ~0.5%–1.5% provide precipitation hardening (Ni3(Ti,Al)).
Other elements (Co, C, Mn, Si, etc.) vary with grade.
Outstanding high-temperature strength (700 deg C–1000 deg C+).
Excellent oxidation/corrosion resistance to oxidizing, sulfidizing, and chloridizing media.
Strong fatigue and thermal-fatigue resistance.
Certain grades (e.g., 718) can be precipitation-hardened for higher strength.
Good weldability while retaining properties.
Typically non-magnetic or weakly magnetic.
Difficult to machine due to hardness/work-hardening behavior.
High material cost because of Ni/Cr/Mo content.
Aerospace: turbine blades, combustors, exhaust systems, rocket hardware.
Nuclear: reactor components and fuel-processing equipment.
Chemical/petrochemical: reactors, heat exchangers, piping, valves, pumps.
Power generation: gas turbines, boilers, steam generators.
Automotive: high-performance exhausts, turbocharger parts.
Marine/offshore equipment exposed to seawater.
Waste-treatment incinerators and exhaust systems needing high temp + corrosion resistance.
Cobalt (Co) matrix alloyed with chromium, nickel, tungsten, iron, etc.
High-temperature strength/stability: resists creep and retains strength for hot-section parts.
Corrosion/oxidation resistance: chromium-rich oxide films protect in acidic or alkaline media.
Wear resistance: complex carbides survive severe frictional service.
High Curie temperature: cobalt remains ferromagnetic at temperatures where nickel alloys lose magnetism.
Aerospace: jet-engine vanes/blades and other high-temperature components.
Medical: artificial joints and implants requiring corrosion resistance and biocompatibility.
Oil & gas: valve seats, sleeves, and bushings exposed to wear/corrosion.
General industry: heat-treatment fixtures, burner nozzles, cutting tools, and dies.
Alpha stabilizers: e.g., aluminum, tin, zirconium.
Beta stabilizers: e.g., molybdenum.
Other additions: iron, vanadium, etc., adjust mechanical performance.
Balanced properties: combines α-alloy corrosion/thermal stability with β-alloy strength and workability.
Heat-treatable: solution/aging treatments can boost strength roughly 50%-100%.
Good high-temperature capability: operates stably around 400 deg C–500 deg C.
Excellent forge/weldability.
Aerospace: turbine blades/vanes and other hot components.
Medical: implants such as artificial joints leveraging corrosion resistance and biocompatibility.
Oil & gas: valve seats, sleeves, bushings needing wear and corrosion resistance.
General industry: heat-treatment fixtures, burner nozzles, cutting tools, and dies.
Beta stabilizers: molybdenum, vanadium, niobium, iron, chromium, etc.
Supplemental elements: aluminum, nickel, zirconium, tin, and others tailor properties.
Excellent workability from the BCC structure (good ductility/toughness for cold forming).
High strength and fracture toughness after solution + aging.
Certain grades exhibit superelastic behavior under stress.
Aerospace: landing gear, compressor disks, wing joints, fasteners.
Biomedical: orthopedic implants and artificial joints leveraging biocompatibility and lower modulus.
Other fields: premium bicycle frames and sporting goods that benefit from high strength-to-weight.
Nickel (Ni): about 50%-51% to deliver the characteristic alloy behavior.
Titanium (Ti): roughly 49%-50% working with nickel to enable SME and superelasticity.
Minor additions: small amounts of copper, chromium, iron, etc., may be added to tune transformation temperatures or specific properties.
Shape memory effect (SME): Deforms at low temperature, then returns to its preset shape when heated to the transformation temperature (about 30 deg C–110 deg C, adjustable) as it changes from martensite to austenite.
Superelasticity: Near body temperature it can accommodate roughly 8%-10% recoverable strain—far beyond ordinary metals—returning to its original form once the load is removed.
Biocompatibility: Non-toxic and non-irritating, suitable for implants and medical instruments.
Corrosion resistance: Resilient against body fluids, seawater, acids, alkalis, and other corrosive media.
High strength and toughness: Provides excellent tensile strength combined with resilience.
Nonmagnetic or weakly magnetic: Compatible with MRI or environments sensitive to magnetism.
Machining challenges: Pronounced work hardening and tool wear require specialized processes such as laser cutting or EDM.
High cost: Complex production and the price of nickel/titanium elevate material cost.
Potential nickel allergy concerns: Some patients may be sensitive to nickel, so medical use demands evaluation.
Medical devices: Vascular stents, guidewires, catheters, orthopedic implants (spinal correctors), and orthodontic wires leveraging SME and superelasticity.
Minimally invasive instruments: Endoscopic components and surgical tools that benefit from recoverable deformation.
Aerospace: Aircraft components, deployable satellite antennas, and rocket parts that require shape-memory actuation.
Robotics and actuators: Robot joints, actuators, and artificial muscles that exploit controllable motion.
Consumer electronics: Flexible antennas, eyeglass frames, and other resilient products.
Automotive: Engine components, thermal valves, and seat-belt pretensioners.
Industrial uses: Thermal switches, pipe couplings, vibration-damping devices, and more.
Architecture and decor: Smart building materials and decorative elements that respond to temperature.
Most grades are nickel-titanium (Ti-Ni) systems; small additions of other elements can fine-tune transformation temperatures and properties.
Outstanding recoverable strain, superelasticity, fatigue resistance, and biocompatibility thanks to reversible phase transformation.
Broadly deployed in aerospace, consumer products, and medical devices wherever large recoverable deformation is required.