AISI 303 1.4305 SUS303 Austenitic Stainless Steel

303 stainless steel is an austenitic stainless steel widely used in applications requiring extensive machining operations such as turning and milling. Due to its excellent machinability, good rust resistance, and sufficient strength and toughness, corresponding grades can be found in various standards. For example: X8CrNiS18-9/1.4305 in European standard EN 10088-3, Y1Cr18Ni9/Y12Cr18Ni9 in Chinese standard GB/T 1220, SUS303 in Japanese standard JIS G4303.

Grade 303 stainless steel significantly enhances its machinability through the addition of elements such as sulfur during the smelting process. This enables it to perform exceptionally well in machining operations like turning, milling, drilling, and tapping. It not only withstands higher cutting speeds but also effectively reduces tool wear and produces short chips that are easily evacuated.

1: Steel equivalent

2: Chemical composition

3: Mechanical properties

Mechanical properties for Y1Cr18Ni9/Y12Cr18Ni9 from standard GB/T1220 and SUS303 from JIS G4303.

Mechanical properties for X8CrNiS18-9/1.4305 from standard EN10088-3.

Mechanical properties at room temperature of steels in the COLD-WORKED condition from standard EN10088-3

4: Supply size & Tolerance & Stock size

Qilu steel stock hot rolled bar and forged bars more than ten thousands tons every month, below our our stock size.

1): Stock diameter for hot rolled bar

2) : Stock diameter for hot forged bar

3): We also have stocks for cold drawn sheet (from 0.2-3mm) and hot rolled plate (from 4mm to 60mm)

Since the stocks change everyday, if you want to know our stock available information, please contact our salesman.

5: Ultrasonic Test

EN10228-3 class III or Sep 1921-84 D/D

6：Steel making & Forging processing

1): Steel making process:

  EF+LF+VD

  EAF+LF+VD

  EF+LF+VD+ESR

  EAF+LF+VD+ESR

2): Forging processing:

Hot forging temperature: 900-1200℃

Cooling in the air

7: Heat treatment  

1）: Solution annealing

Heat 303 steel to 1010-1150℃ in the furnace

Quick cool in the air/water

2):  Aging

Heat to 850-930℃

8：Application

303 stainless steel is widely used in components requiring high-precision, high-efficiency automated machining due to its excellent machinability, good corrosion resistance, and machinability. Its primary applications include:

• Mechanical and automotive industries: Bolts, nuts, screws, shafts, pins, gears, pump shafts, valve cores, etc.

• Electronics, Electrical, and Instrumentation: Sensor housings, connectors, precision instrument components, watch gears, etc.

• Hardware and Consumer Goods: Kitchenware handles, cutlery accessories, high-end hardware fittings, musical instrument components, etc.

• Other Fields: Non-implantable medical devices, fasteners for chemical processing equipment, etc.