AISI 302 Stainless Steel Properties, SS302 Composition, Magnetic, Density, Hardness, Equivalent

Type 302 stainless steel is basically a higher carbon version of type 304, a variant of 18-8 stainless steel. Its carbon content is ≤0.15%, and the minimum chromium content is only 1% less than 304. Grade 302 stainless steel spring wire (specified in ASTM A313) has high heat resistance and good corrosion resistance, and has excellent spring performance in the full hard or tempered condition. The main difference between SS 302, 304 and 304L is the carbon content, so there is a difference in the amount of carbide precipitation that may occur in the heat affected zone (HAZ) after heating and cooling cycles are encountered in welding. The P content of type 303 and 303Se is ≤0.20%, plus 0.15% of Se or S for free machining. These elements are not conducive to weldability and may cause severe hot cracking of the weld metal. AISI 301 has lower nickel and chromium content, so the work hardening rate is higher than AISI 302.

Datasheet & Specification

The following tables and lists give the stainless steel 302 datasheet and specification including chemical composition, physical properties and mechanical properties, heat treatment, welding, etc.

Chemical Composition

SS 302 material chemical composition is listed in the following table.

Datasheet 1, The table below shows AISI 302 chemical composition.

Type 302 Stainless Steel Composition, %
ASTM	AISI (UNS)	C, ≤	Si, ≤	Mn, ≤	P, ≤	S, ≤	Cr	Ni	N, ≤	Mo, ≤	Cu, ≤
ASTM A313/A313M	302 (UNS S30200)	0.12	1.00	2.00	0.045	0.03	17.0-19.0	8.0-10.0	0.1	–	–
ASTM A276/A276M; ASTM A479/A479M; ASTM A580/A580M; ASTM A314; ASTM A473 ASTM A959;		0.15	1.00	2.00	0.045	0.03	17.0-19.0	8.0-10.0	0.1	–	–
ASTM A240/A240M; ASTM 666; SAE J405		0.15	0.75	2.00	0.045	0.03	17.0-19.0	8.0-10.0	0.1	–	–
SAE AMS 5688	SAE 30302	0.15	1.00	2.00	0.04	0.03	17.0-19.0	8.0-10.0	–	0.75	0.75

Notes:

• ASTM A313/A313M: Stainless Steel Spring Wire
• ASTM A276/A276M: Standard Specification for Stainless Steel Bars and Shapes
• ASTM A240/A240M: Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
• ASTM A580/A580M: Stainless Steel Wire
• ASTM A479/A479M: Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels
• ASTM A959: Standard Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels
• ASTM A473: Stainless Steel Forgings
• ASTM A314: Standard Specification for Stainless Steel Billets and Bars for Forging
• ASTM 666: Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate, and Flat Bar
• SAE J405: Chemical Composition of SAE Wrought Stainless Steels
• SAE AMS 5688: Steel, Corrosion-Resistant, Wire 18Cr-9Ni (SAE 30302) Spring Temper

AISI 302 Stainless Steel Properties

The datasheets below list grade 302 stainless steel properties including physical properties and mechanical properties.

Physical Properties

Type 302 grade stainless steel physical properties are listed in the table below such as density, melting point, specific heat, electrical resistivity, elastic modulus (modulus of elasticity), thermal conductivity, and coefficient of thermal expansion (CTE).

Datasheet 2, AISI 302 stainless steel properties – 1.

Notes:

• 10^-6·K^-1 = 10^-6/K
• 1 Ω·mm²/m = 1 μΩ·m
• 1 g/cm3 = 1 kg/dm3 = 1000 kg/m3
• 1 GPa = 1 kN/mm2
• 1 MPa = 1 N/mm2

Type 302 Physical Properties
Density, g/cm3 (lb/in3)	7.9 (0.289)
Melting point, °C (°F)	1400-1420 (2550-2590)
Specific heat capacity, J/kg·K (Btu/lb ·°F)	500 (0.12) at 20 °C (68 °F)
Electrical resistivity, μΩ·m	0.72 at 20 °C (68 °F)
Conductivity, % IACS	3
Magnetic permeability	1.02 (Approximate)
Elastic modulus (Modulus of Elasticity), Gpa (106 psi)	193 (28)
Thermal conductivity, W/m·K (Btu/ft · h ·°F)	16.2 (9.4) at 100 °C (212 °F)
	21.5 (12.4) at 500 °C (932 °F)
Coefficient of thermal expansion (CTE), 10-6/K (μin./in. ·°F)	17.2 (9.6) at 0-100 ℃ (32-212 °F)
	17.8 (9.9) at 0-315 ℃ (32-600 °F)
	18.4 (10.2) at 0-538 ℃ (32-1000 °F)

Acoustic properties
Material	Density (ρ)	Sonic velocities, 105 cm/s			Acoustic impedance
	g/cm3 (lb/in3)	Vl	Vt	Vs	(Zl) 106 g/cm2 · s
Type 302	7.9 (0.29)	5.66	3.12	3.12	4.47
Vl- Longitudinal (compression) waves; Vt- Transverse (shear) waves; Vs- Surface waves For longitudinal waves Zl = ρVl.

SS 302 Mechanical Properties

AISI 302 stainless steel mechanical properties are given in the datasheet below including tensile strength, yield strength, elongation, reduction in area, Brinell and Rockwell hardness, etc.

Datasheet 3, Type 302 stainless steel spring wire properties – 2.

ASTM A313 Stainless Steel Spring Wire Tensile Strength Requirements for Types 302 Class 1 and 304
Diameter (d), in.	Diameter (d), mm	Bend Test, Minimum Number of Bends	ksi	Mpa
≤0.009	≤0.23	–	325-355	2240-2450
0.009<d≤0.010	0.23<d≤0.25	–	320-350	2205-2415
0.010<d≤0.011	0.25<d≤0.28	–	318-348	2190-2400
0.011<d≤0.012	0.28<d≤0.30	–	316-346	2180-2385
0.012<d≤0.013	0.30<d≤0.33	–	314-344	2165-2370
0.013<d≤0.014	0.33<d≤0.36	–	312-342	2150-2360
0.014<d≤0.015	0.36<d≤0.38	–	310-340	2135-2345
0.015<d≤0.016	0.38<d≤0.41	–	308-338	2125-2330
0.016<d≤0.017	0.41<d≤0.43	–	306-336	2110-2315
0.017<d≤0.018	0.43<d≤0.46	–	304-334	2095-2300
0.018<d≤0.020	0.46<d≤0.51	–	300-330	2070-2275
0.020<d≤0.022	0.51<d≤0.56	–	296-326	2040-2250
0.022<d≤0.024	0.56<d≤0.61	–	292-322	2015-2220
0.024<d≤0.026	0.61<d≤0.66	–	291-320	2005-2205
0.026<d≤0.028	0.66<d≤0.71	8	289-318	1995-2190
0.028<d≤0.031	0.71<d≤0.79	8	285-315	1965-2170
0.031<d≤0.034	0.79<d≤0.86	8	282-310	1945-2135
0.034<d≤0.037	0.86<d≤0.94	8	280-308	1930-2125
0.037<d≤0.041	0.94<d≤1.04	8	275-304	1895-2095
0.041<d≤0.045	1.04<d≤1.14	8	272-300	1875-2070
0.045<d≤0.050	1.14<d≤1.27	8	267-295	1840-2035
0.050<d≤0.054	1.27<d≤1.37	8	265-293	1825-2020
0.054<d≤0.058	1.37<d≤1.47	7	261-289	1800-1990
0.058<d≤0.063	1.47<d≤1.60	7	258-285	1780-1965
0.063<d≤0.070	1.60<d≤1.78	7	252-281	1735-1935
0.070<d≤0.075	1.78<d≤1.90	7	250-278	1725-1915
0.075<d≤0.080	1.90<d≤2.03	7	246-275	1695-1895
0.080<d≤0.087	2.03<d≤2.21	7	242-271	1670-1870
0.087<d≤0.095	2.21<d≤2.41	7	238-268	1640-1850
0.095<d≤0.105	2.41<d≤2.67	5	232-262	1600-1805
0.105<d≤0.115	2.67<d≤2.92	5	227-257	1565-1770
0.115<d≤0.125	2.92<d≤3.17	5	222-253	1530-1745
0.125<d≤0.135	3.17<d≤3.43	3	217-248	1495-1710
0.135<d≤0.148	3.43<d≤3.76	3	210-241	1450-1660
0.148<d≤0.162	3.76<d≤4.11	3	205-235	1415-1620
0.162<d≤0.177	4.11<d≤4.50	3	198-228	1365-1570
0.177<d≤0.192	4.50<d≤4.88	1	194-225	1335-1550
0.192<d≤0.207	4.88<d≤5.26	1	188-220	1295-1515
0.207<d≤0.225	5.26<d≤5.72	1	182-214	1255-1475
0.225<d≤0.250	5.72<d≤6.35	1	175-205	1205-1415
0.250<d≤0.278	6.35<d≤7.06	1	168-198	1160-1365
0.278<d≤0.306	7.06<d≤7.77	1	161-192	1110-1325
0.306<d≤0.331	7.77<d≤8.41	1	155186	1070-1280
0.331<d≤0.362	8.41<d≤9.19	1	150-180	1035-1240
0.362<d≤0.394	9.19<d≤10.00	1	145-175	1000-1205
0.394<d≤0.438	10.00<d≤11.12	1	140-170	965-1170
0.438<d≤0.500	11.12<d≤12.70	1	135-165	930-1140
>0.500	>12.70	–	130-160	895-1105
When wire is specified in straightened and cut lengths, the minimum tensile strength shall be 90 % of the values listed in the table.

ASTM A313 Tensile Strength Requirement for SS302 Class 2
Diameter		Cold Drawn Nominal	Stress Relieved
in.	mm	ksi (MPa)	ksi	Mpa
0.050-0.160	1.30-4.00	290 (2000)	290-340	2000-2345
Stress relieved at 800-850°F (430-455°C) for 1/2h and air cooled.

ASTM A276 Type 302 Stainless Steel Mechanical Properties
ASTM	AISI (UNS)	Tensile Strength, Mpa (ksi), ≥	0.2% Yield Strength, Mpa (ksi), ≥	Elongation in 2 in. (50 mm), %, ≥	Reduction of Area, %, ≥	Conditions
ASTM A276/A276M	302, 302B, 304, 304LN, 305, 308, 309, 309S, 309Cb, 310, 310S, 310Cb, 314, 316, 316LN, 316Cb, 316TI, 317, 321, 347, 348	515 (75)	205 (30)	40	50	Annealed, Hot finished
		620 (90)	310 (45)	30	40	Annealed, Cold finished, Dia ≤ 1/2 in (12.7mm)
		515 (75)	205 (30)	30	40	Annealed, Cold finished, Dia > 1/2 in (12.7mm)

	ASTM A240 Type 302 Mechanical Properties
ASTM	AISI (UNS)	Tensile Strength, Mpa (ksi), ≥	0.2% Yield Strength, Mpa (ksi), ≥	Elongation in 2 in. (50 mm), %, ≥	Brinell Hardness, HB, ≤	Rockwell Hardness, HRB, ≤
ASTM A240/A240M	302 (UNS S30200)	515 (75)	205 (30)	40	201	92

ASTM A473 SS302 Mechanical Properties
ASTM	AISI (UNS)	Tensile Strength, Mpa (ksi), ≥	0.2% Yield Strength, Mpa (ksi), ≥	Elongation in 2 in. (50 mm), %, ≥	Reduction of Area, %, ≥	Conditions
ASTM A473/A473M	302 (UNS S30200)	515 (75)	205 (30)	40	50	Annealed

ASTM A479 SS302 Mechanical Properties
ASTM	AISI (UNS)	Tensile Strength, Mpa (ksi), ≥	0.2% Yield Strength, Mpa (ksi), ≥	Elongation in 2 in. (50 mm), %, ≥	Reduction of Area, %, ≥	Conditions
ASTM A479/A479M	302 (UNS S30200)	515 (75)	205 (30)	30	40	Annealed

ASTM A580 Type 302 Mechanical Properties
ASTM	AISI (UNS)	Tensile Strength, Mpa (ksi), ≥	0.2% Yield Strength, Mpa (ksi), ≥	Elongation in 2 in. (50 mm), %, ≥	Reduction of Area, %, ≥	Conditions
ASTM A580/A580M	302 (UNS S30200), 302B (UNS S30215)	620 (90)	310 (45)	30	40	Annealed, cold finished
		515 (75)	205 (30)	35	50	Annealed

ASTM A666 302 Mechanical Properties
ASTM	AISI Type (UNS)	Conditions	Tensile Strength, MPa (ksi), ≥	0.2% Yield Strength, MPa (ksi), ≥	Elongation in 50 mm (2 in.), %, ≥	Brinell Hardness (HB), ≤	Rockwell Hardness (HRB), ≤
ASTM A666	302 (UNS S30200)	Annealed	517 (75)	205 (30)	40	201	92
		Full Hard	1275 (185)	965 (140)	3 (<0.015 in.); 4 (≥ 0.015 in)
		1/2 Hard (Half Hard)	1035 (150)	760 (110)	9 (<0.015 in); 10 (≥ 0.015 in)
		3/4 Hard	1205 (175)	930 (135)	5 (<0.015 in); 6 (≥ 0.015 in)
		1/4 (Quarter-hard) Hard	862 (125)	517 (75)	10 (≤ 0.03 in); 12 (> 0.03 in)
		1/8 Hard	690 (100)	380 (55)	35
	302 plate, strip, sheet	1/16 Hard	585 (85)	310 (45)	40
	302 flat bar		620 (90)	310 (45)	40 (>0.030 in)

Type 302 Grade Stainless Steel Heat Treatment

• SS 302 annealing temperature is 1010-1120 °C (1850-2050 °F), recommended temperature is 1400 °C (1900 °F)
• Oven stress-relief temperature and time for wire: 345 °C (650 °F), 30 minutes.
• Typical stress relief temperature for SS302 steel spring wire: 425-480 °C (800-900 °F) based on 30 min at temperature, only suitable for stress relief after coiling and not valid for stress relieving after shot peening. When the spring is to be used at a high temperature, the stress relief temperature should be close to the upper limit of this range to minimize relaxation in use. Otherwise, lower temperature are better.
• SS 302 typical forging temperature range is 925-1260 °C (1700-2300 °F).

Welding

SS 302 may be readily welded by friction welding, seam welding and flash welding process; arc welding not recommended. If a filler metal is required, E/ER308 or E/ER308L is recommended.

Heat Resistance

Maximum service temperatures in air

• Intermittent service: 870 °C (1600 °F)
• Continuous service: 925 °C (1700 °F)

Corrosion Resistance

Corrosion of AISI 302 stainless steel in marine environment
AISI Type	Average corrosion rate, mm/year	Average depth of pits, mm (mils)	Appearance
302	<2.5 x 10-5	0.03 (1.2)	Spotted with rust stain on 10% of surface

Applications

AISI 302 stainless steel is widely used in industrial and architectural industries, such as stamping, steel springs, wire rope, metal mesh, woven wire mesh, screen mesh, stainless steel decorative mesh, perforated metal sheet, steel mesh, metal filter and strainer, steel washer, handrail, etc.

SS 302 Equivalent Material

Grade 302 stainless steel equivalent to European EN standard (Germany DIN EN, British BSI…), Chinese GB, ISO, and Japanese JIS, etc.