Industrial 303 Stainless Steel Bar Stock for CNC and Turning Work

Products Specification

Industrial 303 Stainless Steel Bar Stock for CNC and Turning Work

The 303 stainless steel bar stock is a top-tier material widely used in industries that demand high precision and excellent machinability, especially in CNC machining, turning, and screw machining operations. Known for its outstanding cutting performance and corrosion resistance, 303 stainless steel is the preferred choice for high-speed automated production, ensuring both quality and cost-effectiveness.

This product page is designed to provide engineers, manufacturers, and procurement specialists with detailed information about 303 stainless steel bar stock—its material properties, available sizes, surface finishes, and its applications in industrial machining. This high-performance material is perfect for turning, drilling, threading, milling, and CNC machining of complex components requiring precision and durability.

1. Product Overview

The 303 stainless steel bar stock is manufactured to meet the highest standards of quality and performance. Its primary feature is the sulfur addition, which significantly enhances machinability without compromising on the material’s strength and corrosion resistance. This makes it ideal for industries where machining efficiency is paramount, such as the automotive, aerospace, and electronics sectors.

Key Features

• Superior machinability: Exceptional cutting performance with low tool wear

• Corrosion resistance: Excellent resistance to mild environments and chemicals

• Bright finish: Smooth, aesthetically pleasing surface ideal for high-visibility parts

• Dimensional accuracy: Tight tolerances and high straightness for precision work

• Cost-efficient: Reduced machining time, lower tool wear, and fewer part rejects

The 303 stainless steel is specifically formulated for CNC machining and turning work, where high-speed cutting and complex geometries are involved.

2. Chemical Composition

303 stainless steel is a member of the AISI 300 series and contains several elements that enhance both machinability and performance. The table below outlines the typical chemical composition of 303 stainless steel bar stock.

Table 1: Chemical Composition of 303 Stainless Steel

The sulfur content (0.15 – 0.35%) is crucial for the exceptional machinability that 303 stainless steel provides. The sulfur improves chip formation during cutting, making it easier to machine at higher speeds.

3. Mechanical Properties

The 303 stainless steel bar stock is engineered to provide a balance of strength, ductility, and toughness while ensuring ease of machining. The following mechanical properties apply to 303 stainless steel in its annealed condition:

Table 2: Mechanical Properties

These properties make 303 stainless steel suitable for a variety of precision applications, including parts subject to light mechanical stress and medium-impact environments.

4. Physical Properties

In addition to its mechanical characteristics, 303 stainless steel has distinct physical properties that ensure reliable performance in various environmental conditions.

Table 3: Physical Properties

The thermal conductivity and coefficient of expansion are moderate, which is suitable for most industrial and manufacturing environments.

5. Surface Finishes and Tolerances

To meet specific machining and application requirements, 303 stainless steel bar stock comes in a range of surface finishes. Whether you require a polished finish for aesthetic components or a ground finish for precision machining, this material offers a high level of versatility.

Table 4: Surface Finish Options

Each of these finishes provides different levels of precision and appearance, depending on the demands of the application.

Standard Dimensions and Tolerances

303 stainless steel bar stock is available in various diameters and lengths, with custom options for specific applications. The typical diameter range for standard bar stock is from 4 mm to 200 mm, with lengths ranging from 1 meter to 3 meters or customized lengths depending on customer specifications.

Table 5: Available Sizes and Tolerances

6. Applications

Due to its unique properties, 303 stainless steel bar stock is ideal for high-speed machining applications in a variety of industries. Below are some of the most common industrial applications of 303 stainless steel:

Common Applications

• CNC Machined Components: Precision-machined parts for automotive, electronics, and industrial equipment

• Turned Parts: Shafts, pins, bushings, and other cylindrical components

• Fasteners and Fittings: Bolts, nuts, screws, and washers used in demanding applications

• Instrument Parts: Housings and casings for instrumentation devices

• Gears and Couplings: Components used in mechanical drive systems

• Aerospace Parts: Non-critical components like brackets and fittings

• Food and Beverage Equipment: Machinery components that come into contact with food products (low-corrosion environments)

Industries That Benefit from 303 Stainless Steel Bar Stock

• Automotive: Engine components, fasteners, and structural parts

• Aerospace: Precision parts for aircraft and spacecraft

• Medical Devices: Surgical tools and non-implantable devices

• Electronics: Connectors, housings, and components for electronic devices

• Marine: Parts exposed to mild seawater environments

• Food Processing: Equipment parts and machines in contact with food

• General Engineering: Mechanical and structural components for various industries

7. Comparison of Stainless Steel Grades

While 303 stainless steel bar stock is an excellent choice for machinability and corrosion resistance, it is important to compare it to other stainless steel grades for specific application needs.

Table 6: 303 Stainless Steel vs. 304 and 316

303 stainless steel is best suited for applications where machinability is a higher priority than extreme corrosion resistance, which makes it ideal for CNC turning and machining operations.

8. Manufacturing Process

To ensure the highest quality of 303 stainless steel bar stock, the manufacturing process involves multiple stages of quality control and precision finishing:

1. Hot Rolling: Initial forming of the stainless steel into bars

2. Cold Drawing: To improve dimensional accuracy and surface finish

3. Centerless Grinding: Achieves tight tolerances and smooth surfaces

4. Surface Finishing: Polishing