303 Stainless Steel Machined Parts & Properties | ISO 9001:2015 | Penta Precision

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303 Machining, Properties & Components

What is 303?

Stainless steel 303 is the most readily machineable austenitic stainless steel.

The addition of Sulphur in the steel composition improves machining but also causes a decrease in the corrosive resistance and a slight reduction of the toughness when compared to 304.

Main Attributes of Stainless 303:

  • Excellent machinability
  • Non-seizing and non-galling properties make it ideal for moving parts
  • Good mechanical resistant properties 
  • Good corrosion resistance in mild environments (less corrosion resistance than 304)
  • Not suitable for moist/marine environments
  • Non-magnetic
  • Good resistance to oxidisation when intermittently exposed to temperatures of up to 760°C and continuous exposure to 870°C although not recommended for continuous use at 425-860°C as sensitive to carbide precipitation
  • Poor weldability


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Detailed information about 303 for designers including UK stock sizes and technical properties can be found in the tabs below. Please note: this information is provided as a guide only. All information is based on our present knowledge and is given in good faith. No liability will be accepted by Penta Precision in respect of any action taken by any third party in reliance thereon.

Similar or obsolete designation and trade names

You may also see 303 referred to as:

303 Components, Applications & Industries

Here are some examples of the industries and components for which 303 stainless steelis appropriate. This is by no means an exhaustive list. Please do get in touch if you are considering using 303 and we can talk through your project with you.

Typical Components & Applications:

303 is typically used in applications that require parts to be heavily machined e.g.

  • Shafts
  • Bushings
  • Gears
  • Food processing & production equipment
  • Valve bodies & fittings
  • Pump components
  • Nuts, bolts & screws
  • Aircraft fittings & parts
  • Springs
Industry Examples:
  • Aerospace
  • Electrical
  • Architecture
  • Food & packaging



    303 Replacement Part

    303 Stainless Processing Machinery Replacement Part

    303 Machining Service

    Penta Precision provides highly accurate machined parts in stainless 303. Customers turn to us when they have had quality and delivery issues with their existing suppliers and need a reliable precision machining partner.

    Penta Precision provides the following 303 stainless steel services: 

    Reasons to Choose Penta:

    We are regularly machining 303 for customers all over the UK. Our customers depend on our machining expertise as well as our outstanding delivery performance, to machine the highest quality parts. Contact us to discuss how we can help you with your 303 machining requirements. 

    Can we meet your
    303 stainless steel machining needs?
    Call our engineering team on
    +44 (0) 23 9266 8334
    or contact us via our email form

    “Penta Precision produced two polished acrylic mould prototypes for us, which needed to fit together seamlessly. Penta produced the mould to the exact size and within the time that we needed. I will definitely use them again for future projects.” Matt - Design Manager

    Tel: +44 (0) 2392 668 334

    Fax: +44 (0) 2392 668 335

    Connect with us:

    Penta Precision Engineering Ltd

    Aspen House

    Airport Service Road



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