AISI 430 vs AISI 430F vs AISI 430FR

A complete comparison table for AISI 430 vs 430F vs 430FR, covering composition, mechanical, thermal, electrical/magnetic, processing, and corrosion properties.

Property	AISI 430	AISI 430F	AISI 430FR
UNS Number	S43000	S43020	S43000
EN Number	1.4511, 1.4016	—	—
Condition	Annealed / annealed – cold or hot finished	Annealed	Annealed
Type	Standard ferritic grade	Free-machining (Se/Mo added)	Free-machining, sulfur-added (magnetic solenoid grade)
Typical Uses	Auto trim, decorative/household trim, fasteners, flatware, architectural sections, piping, heat exchanger tubing	Same base uses; specified where free-machining is required	Solenoid housings, cores, pole pieces – magnetic components in corrosive environments
C (Carbon)	0 – 0.12	0 – 0.12	0 – 0.06
Cr (Chromium)	16 – 18	16 – 18	17.2 – 18.2
Mn (Manganese)	0 – 1	0 – 1.25	0 – 0.8
Mo (Molybdenum)	—	0 – 0.6	0 – 0.5
P (Phosphorus)	0 – 0.04	0 – 0.06	0 – 0.03
S (Sulfur)	0 – 0.03	0.15 – 0.25	0.24 – 0.4
Si (Silicon)	0 – 1	0 – 1	1 – 1.5
Density (g/Cm³)	7.62 – 7.82	7.62 – 7.82	7.57 – 7.77
Young’s Modulus (GPa)	195 – 205	195 – 205	195 – 205
Yield Strength (MPa)	245 – 345	430 – 470	325 – 365
Tensile Strength (MPa)	430 – 600	538 – 655	538 – 655
Elongation (% strain)	17 – 30	10 – 15	10 – 15
Hardness – Brinell (HB)	155 – 192	185 – 195	161 – 179
Hardness – Rockwell C (HRC)	0 – 11	9 – 12	0 – 12
Fatigue Strength @ 10⁷ cycles (MPa)	225 – 249	237 – 300	237 – 300
Fracture Toughness (MPa·m^0.5)	61 – 164	61 – 164	61 – 164
Melting Point (°C)	1430 – 1.510	1430 – 1.510	1430 – 1.510
Max. Service Temp. (°C)	750 – 870	750 – 870	750 – 870
Min. Service Temp. (°C)	-73 – -43	-73 – -43	-73 – -43
Thermal Conductivity (W/m·°C)	23 – 27	23 – 27	23 – 27
Thermal Expansion (µstrain/°C)	10 – 11	11.5 – 12.5	10 – 12
Electrical Resistivity (µohm·cm)	53 – 65	53 – 76	70 – 76
Magnetic Type	Magnetic	Magnetic	Magnetic
Metal Casting	Unsuitable	Unsuitable	Unsuitable
Metal Cold Forming	Acceptable	Unsuitable	Unsuitable
Metal Hot Forming	Acceptable	Limited use	Limited use
Metal Press Forming	Excellent	Excellent	Excellent
Metal Deep Drawing	Excellent	Unsuitable	Unsuitable
Machining Speed (m/min)	30.5	33.5	42.7
Weldability (overall)	Good (preheat/PWHT required)	Unsuitable (not recommended)	Unsuitable (not recommended)
Brazeability	Fair	Fair	Fair
Carbon Equivalency	0.533 – 0.787	0.533 – 0.835	0.607 – 0.777
PREN (Pitting Resistance Eq. No.)	16 – 18	16 – 20	17.2 – 19.9
Pitting & Crevice Corrosion	Low (<20)	Low (<20)	Low (<20)
Stress Corrosion Cracking	Slightly susceptible	Susceptible	Not susceptible
Intergranular (Weld Line) Corrosion	Moderate	Moderate	Moderate
Sea Water	Moderate	Restricted	Good
Sour Oil and Gas	Restricted	Poor	Poor
Weak Acids / Strong Acids	Excellent / Acceptable	Excellent / Acceptable	Excellent / Acceptable
Galling Resistance (Adhesive Wear)	Limited use	Limited use	Acceptable (S>0.15%)

Notes: 430F is a Se/Mo-type free-machining grade; 430FR is a sulfur-added free-machining grade used for magnetic solenoid components. Weldability is generally not recommended for free-machining grades (430F/430FR) due to sulfur/selenium additions causing hot cracking risk.