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18-8 Stainless Steel vs Grade 5 – What’s the Difference

18-8 Stainless Steel vs Grade 5

When choosing bolts and fasteners, you want to use the right material. Two common choices are 18-8 stainless steel and grade 5. They may seem similar at a glance, but key differences make 18-8 stainless steel the superior choice. This blog explores those differences and explains why 18-8 stainless steel should be your go-to option.

What is 18-8 Stainless Steel?

18/8 stainless steel is a type of steel alloy that contains 18% chromium and 8% nickel. It is highly resistant to rust and corrosion, making it an ideal choice for cookware, utensils, food storage containers, and other kitchen items. Its non-reactive properties also make it safe for contact with food products.

What is Grade 5?

Grade 5 metal is an alloy of titanium and aluminium. It has excellent strength-to-weight ratio, corrosion resistance, and fatigue resistance when subjected to extreme temperatures. It is often used in aerospace applications and motorsports due to its lightweight and durability.

Difference Between 18-8 Stainless Steel and Grade 5


The first difference between 18-8 stainless steel and grade 5 is their composition. Grade 5 bolts are made of carbon steel, which is a slightly lower grade than stainless steel. On the other hand, 18-8 stainless steel comprises 18% chromium and 8% nickel. This composition gives it its name. Chromium makes the steel more resistant to corrosion and tarnishing, while nickel adds strength and toughness. Because of its composition, 18-8 stainless steel is often called “Marine Grade” or “A4 Stainless Steel.”

Corrosion Resistance

As mentioned, 18-8 stainless steel is resistant to corrosion and tarnishing. This property makes it ideal for use in environments where it is likely to come into contact with water, such as marine and coastal areas. Grade 5 bolts, on the other hand, are less corrosion-resistant and may rust or tarnish over time, especially in wet or humid conditions.


While 18-8 stainless steel and grade 5 bolts are strong, the former is generally stronger. This is because stainless steel is a harder material than carbon steel, which is what grade 5 bolts are made of. Additionally, the nickel in 18-8 stainless steel provides added strength and toughness, making it more resistant to wear and tear.


Another difference between 18-8 stainless steel and grade 5 is their appearance. 18-8 stainless steel has a shiny, polished look that can enhance the appearance of whatever it’s used on. Grade 5 bolts, however, have a more realistic look and may not be as visually appealing. Tarnishing and corrosion only further detract from their appearance over time. With 18-8 stainless steel, this is never a concern.


Cost is a possible downside of using 18-8 stainless steel over grade 5. It is generally a more expensive material than carbon steel. The benefits of using 18-8 stainless steel – including its corrosion resistance, strength, and appearance – far outweigh the cost difference.


In conclusion, while grade 5 bolts may seem viable, 18-8 stainless steel is the superior choice. From its composition to its strength to its corrosion resistance and appearance, it outperforms grade 5. Though 18-8 stainless steel may be slightly more expensive, its added benefits make it worth the investment. So the next time you consider a bolt or fastener, choose 18-8 stainless steel.

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