While it is more difficult to pinpoint who invented steel, Harry Brearley is often credited with the finding of stainless steel. In 1913, while working to create a metal that would keep gun barrels from wearing down, the metallurgist created a steel with 12.8% chromium content. Steels high in chromium are less susceptible to corrosion. Stainless steel takes many forms that are used in our daily lives. For example, kitchen roofing materials, hot water tanks, MRI scanners, and can-cutting cutlery sold on late night infomercials all use some form of stainless steel. Stainless steel can even be used as a kind of soap. While it won’t necessarily kill germs, a piece of stainless steel can de-stink a potent smell. ASTM A313/A313M-18: Standard Specification for Stainless Steel Spring Wire provides guidelines for the standard specification of stainless steel spring wire.
In a past post, we discussed another type of steel wire. The steel wires centered on in ASTM 228/A228M-18: Standard for Steel Wire, Music Spring Quality, while high in strength, do not have the same stainless steel properties as the wires covered by ASTM A313/A313M-18. The spring wire discussed in ASTM A313/A313M-18 is intentionally corrosive. Stainless steel contains a minimum of 10.5% chromium. In addition, other elements are often used to up the amount of corrosion resistance.
There are over 100 grades of stainless steel. To make categorization of these steels easier, they are put into classifications. Most of them can be put into one of five groups:
- Precipitation hardening
ASTM A313/A313M-18 has a scope that provides information on austenitic, austenitic-ferritic, and age-hardenable stainless steel round spring wire meant especially for the manufacture of springs.
ASTM A313/A313M-18’s referenced documents include:
- ASTM A555/A555M Specification for General Requirements for Stainless Steel Wire and Wire Rods
- ASTM A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
- ASTM E527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)
- SAE J1086 Numbering Metals and Alloys
ASTM A313/A313M-18 revises the 2017 version of the same standard. Changes to the standard include:
- A footnote was added to Table 1 that states Nb and Cb are equivalent terms.
ASTM A313/A313M-18: Standard Specification for Stainless Steel Spring Wire is available on the ANSI Webstore.