Stainless Steel 304/304L

General Description

Type 304/304L stainless steel, with its chromium-nickel content, is the most versatile and widely used of the austenitic stainless steels. No other grades of stainless steel come in so many forms and finishes or is used with such diverse applications. These grades can be severely deep drawn without intermediate annealing, which has made these grades the industry standard in the manufacture of drawn stainless parts. The lower carbon content in 304L grade increases resistance to intergranular corrosion following welding or stress relieving. These grades of stainless steel are the most economical and readily available.

Applications

  • Curettes
  • Screws / prostheses / plates
  • Medical needles
  • Medical syringes
  • Sensor probes
  • Catheters
  • Heat exchangers

Reference Standards

  • AMS5566
  • AMS5569
  • AMS5647
  • AMS6845
  • ASTM A213
  • ASTM A269
  • ASTM A312
  • ASTM A632
  • ASTM F899
  • Mil-T 8504
  • Mil-T 8606

Characteristics

  • Cold working will achieve higher tensile strengths as well as leaving the material slightly magnetic.
  • Annealing will result in little to no magnetism—perfect for operating theatres or implants within the body.
  • The properties can easily be manipulated to allow for forming of complex shapes.
  • Most economical and readily available stainless steel
  • Good general corrosion resistance

Typical Chemistry

Carbon 0.07%*
Manganese 2.00%
Phosphorous 0.045%
Sulfur 0.03%
Silicon 0.75%
Chromium 18.00% 20.00%
Nickel 8.00% 10.50%
Nitrogen 0.10%

*304L has a lower carbon content of 0.03% max

Possible Mechanical Properties

Hardness 82 HRB 38 HRC
Tensile Strength 90 ksi 170 ksi
Elongation 50% 5%
Tensile Strength vs Elongation

General Properties

Density 0.289 lb/in3
Elastic modulus 28000 ksi
Shear modulus 11200 ksi
Mean specific heat (32-212F) 0.120 Btu/lb/F
Thermal conductivity (32-212F) 112 BTU-in/hr-ft2 - F
Mean CTE (32-1200F) 10.4x10-6 in/in/F
Electrical resistivity (68F) 72 microohm-cm
Magnetic Permeability (Annealed) 1.020

Tubing-specific Requirements

  • Lengths: Tubing is normally furnished in mill lengths of 5 ft, but it can be supplied in up to 20 ft lengths with a shear cut end.
  • Cut End Finish: Precision cut-to-length pieces with burr-free ends can be furnished when specified.
  • Roundness: Difference in minimum and maximum OD measurements must be equal or less than half the OD tolerance.
  • Surface Finish: OD and ID surface finish (Rq or RMS) limits may be specified. ID and OD surface finish values are only reported for dimensions >0.020".
  • Typical OD Surface: < 20 μin Rq.
  • ID Surface finish: Depends on the reduction (drawing) method. Free sunk tubing has a typical ID surface finish <150 μin Rq. Plug drawn tubing can have an ID surface finish range with values as low as < 20 μin Rq.
  • Straightness: No deflection greater than 5% of the outside diameter for tubing with OD > 0.020” or 0.001” maximum deflection for tubing with OD <0.020”. Any special straightness requirements shall be agreed upon between the purchaser and supplier. Tubing should not “wobble” as defined per ASTM F2819

Additional tubing specification information can be found in K001-15a Standard Specification for Miniature Laser Welded and Drawn Stainless Steel and Nickel-Chromium Alloy Tubing for General Use.

Available dimensions

K-Tube has the capability to make tubing with the wall thickness and outside diameter combinations in the table below. Tubing with an OD/Wall ratio lower than 20:1 can be drawn to the final dimensions. Tubing with an OD/Wall ratio between 20:1 and 40:1 must be centerless ground to the final dimensions. K-Tube's capabilities are constantly improving, please inquire if your dimensions are outside of the listed dimensions.

Download The 304-304L K-Tube Stainless Steel Data Sheet

Download the 304-304L K-Tube Stainless Steel Data Sheet (PDF) to easily share all the details on this page with your team.

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