301 Half Hard vs 301 Full Hard Stainless Steel

The grade 301 stainless steel has five different temper conditions 1/4 hard, half hard, 3/4 hard, full hard, and spring hard. These temper conditions depend upon the required strength of 301 stainless steel. The 301 stainless steel has excellent corrosion resistance and a bright surface finish; therefore, it is used in many structural and decorative applications.

Due to its high work hardening rate, yield strength and tensile strength will increase significantly with each addition of cold work. The tempering process plays a very important role in making stainless steel.

Tempering is when we heat the stainless steel to a specific, precise temperature below the critical point. This process is done in open air or vacuum. Mostly the different temper conditions of 301 stainless steel are obtained through cold working, not heat treating.

Table of Contents

What is 301 half hard stainless steel?

The austenitic stainless steel 301 half hard has undergone cold rolling to achieve its half hard condition. The 301 1/2 hard has minimum 930 Mpa tensile strength and 510 Mpa yield strength, which makes it perfect for many applications.

The different tempers conditions of 301 stainless steel and mechanical qualities are obtained through cold working. Moderate tensile strength is required for the 301 half hard (AMS 5518) material to produce items that need strength and require only moderate drawing or forming.

What is 301 full hard stainless steel?

301 full hard stainless steel is austenitic stainless steel that is cold rolled to a full hard state, making them different from other 301 forms. This makes the metal more suitable for forming and extends its durability. Type 301 has a minimum yield strength of 1030 Mpa and a minimum tensile strength of 1320 Mpa in its full hard condition. It is perfect for springs because of its hardness and toughness combination.

301 half hard AMS 5518 VS 301 full hard AMS 5519

Half hard AISI 301 and full hard AISI 301 are grades of the same material. They both share an alloy composition and many physical characteristics, but due to different processing, they acquire different mechanical properties.

The tensile strength and hardness of 301full hard stainless steel are greater than half hard. Therefore, it is used where high tensile strength and hardness are required. On the other hand, 301 half hard stainless steel has more ductility, formability, and toughness than full-hard stainless steel. The half hard stainless steel is mainly used where we need strength, drawing and forming properties.

Comparison of 301 half hard and 301 full hard

When we compare 301 half hard and full hard, there are some differences in their properties. Let’s see the comparison from the following tables.

Mechanical properties

Mechanical properties	Half Hard AMS5518	Full Hard AMS 5519
Tensile strengthMin MPa	930	1320
Yield strength0.2% Min MPa	510	1030
Elongation	10%	0-3%
Hardness Vickers	310-370 HV	430-490 HV
Shear strengthMPa	730	860
Fatigue strengthMPa	540	550
Poisson’s ratio	0.28	0.28
Shear modulusGPa	77	77

Thermal properties

Thermal properties	Half Hard AMS5518	Full Hard AMS 5519
Latent heat of fusionJ/kg	280	280
Maximum temperature corrosion°C	410	410
Maximum temperature mechanical°C	840	840
Specific heat capacity J/kg-K	480	480
Thermal conductivity W/m-k	16	16
Thermal Expansion µm/m-K	17	17

Physical properties

physical properties	Half Hard AMS5518	Full Hard AMS 5519
Density g/cm3	7.88	7.88
Melting range°C	1399-1421	1399-1421
Specific gravity	8.03	8.03
Modulus of elasticity in tensionGPa	193	193

Common calculations

Properties	Half Hard AMS5518	Full Hard AMS 5519
Pitting Resistance	18	18
Resilience: Ultimate (Unit Rupture Work), MJ/m3	220	99
Resilience: Unit (Modulus of Resilience), kJ/m3	1880	2970
Stiffness to Weight: Axial points	14	14
Stiffness to Weight: Bending, points	25	25
Strength to Weight: Axial, points	42	52
Strength to Weight: Bending, points	32	37
Thermal Diffusivity, mm2/s	4.2	4.2
Thermal Shock Resistance points	25	31

Chemical composition

Elements	Half Hard	Full Hard
Carbon	0.15% Max	0.15% Max
Manganese	2.0% Max	2.0% Max
Silicon	1.0% Max	1.0% Max
Chromium	16.00-18.00%	16.00-18.00%
Nickel	6.00-8.00%	6.00-8.00%
Phosphorus	0.045% Max	0.045% Max
Sulfur	0.030% Max	0.030% Max
Nitrogen	0.10% Max	0.10% Max
Iron	Balance	Balance

Applications of 301 half hard and 301 full hard stainless steel

Due to its good corrosion resistance, high ductility, and strength, 301 half hard and full hard stainless steel are used in many applications.

Standard applications for stainless steel 301 Half Hard and Full Hard include the aerospace, automotive, architectural, ornamental, industrial, and food and beverage industries.