One-stop Fastener
Custom Manufacturing Expert

Ask me anything

Contact information for headquarters sales
Contact information for Indonesia sales
Contact information for India sales

Tel: +86 13560730094

Consult

Categories:

Fastener Stainless Steel: Types & Forms

[Abstract]:Stainless steel is roughly classified into 200, 300 and 400 series. The 300 series is the most widely used, while the 200 and 400 series serve as its alternatives.

As one of the most widely used materials in the fastener industry, stainless steel significantly affects product selection and cost control. This article provides a detailed analysis of its mainstream classifications, material characteristics and industrial forms.

In industrial classification, stainless steel is generally divided into three major series: the 200 series, 300 series and 400 series. The 300 series dominates fastener applications, while the 200 and 400 series serve as alternative materials for specific scenarios. Notably, the 400 series is essentially ferritic stainless steel, commonly known as “stainless iron”. It contains no nickel element and is magnetically attractable. In contrast, both 200 and 300 series stainless steel contain nickel and are non-magnetic, which provides a simple method to distinguish the 400 series from the other two categories.

Material prices are highly correlated with nickel content. The 300 series features the highest nickel content and is most sensitive to nickel price fluctuations; the 200 series has low nickel content; the 400 series is completely nickel-free. As the most representative grade of the 300 series, 304 stainless steel price trends typically reflect the overall market fluctuation and serve as a core cost reference for the fastener industry.

The 300 series includes multiple refined grades such as 304, 304L, 316, 316L, 321, 309S and 310S. Grade differences are determined by variations in chemical composition, which directly differentiate mechanical and corrosion-resistant properties. For example, the primary difference between 304 and 304L, as well as 316 and 316L, lies in carbon content, where the letter “L” denotes low-carbon stainless steel with improved intergranular corrosion resistance.

In terms of material forms, stainless steel is mainly supplied in five types: coils, sheets, profiles, steel pipes and finished components. Among them, coils and sheets are the most essential forms for fastener manufacturing. Profiles are processed from steel plates into shaped materials such as angle steel, flat steel, I-beams and channel steel. Steel pipes mainly refer to seamless pipes, distinguished from welded pipes by one-piece forming technology. Component products include pipe fittings such as elbows and flanges.

Coils and sheets are essentially identical in material properties and differ only in delivery form. Coils are supplied in continuous rolled form, while sheets are supplied as individual flat plates. Plates directly produced as finished sheets are defined as original sheets, mostly thick plates over 16 mm, which cannot be rolled into coils due to thickness limitations.

The two forms adopt different pricing mechanisms. Coils are priced by actual weighed weight with relatively higher unit cost, while sheets are calculated by theoretical weight. In actual trade, the measured thickness of sheets is usually slightly lower than the nominal thickness, forming a common industry price difference.

According to rolling processes, stainless steel plates are classified into hot-rolled and cold-rolled types. Hot-rolled plates are marked NO.1, while cold-rolled plates adopt 2B or BA surface finishes. BA surfaces provide higher smoothness and brightness close to a mirror effect, whereas formal mirror stainless steel requires customized secondary processing with no standard stock available.

Most standard 304 sheets are processed by uncoiling and flattening stainless steel coils. Custom-length cutting is available to meet personalized dimensional requirements for fastener production.

In terms of thickness specifications, domestic cold-rolled plates are generally below 3 mm, while hot-rolled plates are mostly above 3 mm. A thickness of 3 mm covers both hot-rolled and cold-rolled products. Imported cold-rolled plates can reach 4–6 mm in thickness. Industrially, hot-rolled plates of 3–12 mm are defined as medium plates, and those above 12 mm are thick plates, collectively referred to as hot-rolled medium and thick plates. Cold-rolled products are uniformly defined as cold-rolled thin plates, providing diverse material options for fastener design and manufacturing.

Professional consultant team online, ready to provide solutions for you

Contact Now

Fastener Stainless Steel: Types & Forms

Related News

Latest Products