Stainless Steel vs Galvanized Steel: Some Key Differences

Are you done looking for screws? You’ve likely seen that some of them are made of 100% stainless steel, while others are made of galvanized steel. Because of this, it’s hard to recognize the difference between them. Keeping in view everything, the two of them look and function similarly. So, what’s the contrast between stainless steel and galvanized steel?

These two kinds of screw materials are sold by every home-improvement retailer on the planet. There’s no simple response to this inquiry that which is best since the two kinds of steel have their pros and cons. All things considered, stainless steel and galvanized steel have the equivalent common objective of ensuring against rust and corrosion and they accomplish this objective astoundingly well. Before selecting one for a utility, first, we have to do a deep analysis of both these materials. Their quality, strength, and pricing, hence everything matters.

 

Stainless Steel

The term stainless steel is utilized to portray steel that has been blended in with at least 10% chromium. The expansion of chromium as a composite assist with securing against rust.

304 Grade Stainless Steel
316 Grade Stainless Steel

Properties
Stainless steel is shinier and progressively refined looking. While stainless steel isn’t invulnerable to rust, it positively has a more significant level of opposition than 100% steel. This is the reason stainless steel is frequently utilized in open-air conditions where there’s a lot of dampness. The chromium attempts to secure the metal against rust.

Composition
Stainless steel alloys are composed primarily of iron, with varying amounts of carbon, chromium, and other elements such as nickel, molybdenum, and titanium. The composition of these alloys can be adjusted to provide specific properties such as corrosion resistance, strength, and ductility. Threading and cold forming cause stainless bolts to become slightly magnetic, some fasteners will be more magnetic than others depending on size and how quick the cold forming process is. The detailed composition of stainless steel types is listed below;

Grades
(by ASTM standard)
Content by weight
Chrome Nickel Carbon (max) Molybdenum (max)
18-8 Stainless Steel 18% 8% 0.08% 0%
305 Stainless Steel 17%-19% 8%-10% 0.12% 0%
316 Stainless Steel 16%-18% 10%-14% 0.08% 2%
410 Stainless Steel 11.5%-13.5% 0% 0.15% 0%

 

Galvanized, Plated

Galvanized steel, then again, is a sort of steel that has been covered in a layer of zinc. Much like its partner, galvanized steel is additionally made to secure against rust. The zinc goes about as an obstruction of assurance between airborne dampness and the steel, shielding it from rust.

Zinc Plated Steel

 

Hot Deep Galvanized Steel

 

Yellow Zinc Plated Heat Hardened Steel

Properties
Galvanization is a procedure that plates steel in a way that shields it from rusting or eroding. This makes galvanized steel incredible for indoor and outside use. It additionally implies that you can support the galvanized tie or metal piece in a way that reaches another metal or material and do so by utilizing a different fastener or screw. It has different coatings;

Composition

Galvanized steel comprises of plunging a completed steel item into a hot shower of zinc. In this procedure, a bond happens, mixing the zinc to the outside of the steel. The zinc plate bonding develops until the external layer is fully composed of zinc. The external layer of this new steel item is harder than the steel to which it is attached to. The steel currently has a defensive layer of plating shielding it from rust. It has different coatings;

Material Coating Thickness Temperature Range Expected
Durability
Suitability
US Metric US Metric
Zinc Plated Up to 1 mil Up to 25 μm -148°F – 392°F -100°C – 200°C 15+ years Indoor

&

Outdoor

Hot Dipped 1.7 – 3.4 mils 43-58 μm -148°F – 392°F -100°C – 200°C 45-80 years Indoor

&

Outdoor

Electroplated 0.2 mil 5 μm -148°F – 392°F -100°C – 200°C 10+ years Indoor

&

Outdoor

*mil – a unit length in the US system equal to a thousandth inch or 0.001 inches.
*μm – a unit of length in the Metric system equal to one millionth (10-6) of a meter.

Comparison

Strength Analysis

Both galvanized and stainless screws are the absolute best materials for strength and quality. They are particularly valid for metal fixation, that’s why they are commonly known as self-tapping metal screws. Nonetheless, there are some measures you will need to observe while selecting between the two.

Stainless steel screws are made out of a few components, with chromium being the most noteworthy of the added substances and nickel a nearby second. The greatest and most significant point is that the whole of the clasp is stainless. It isn’t only a covering. Its quality and rust insurance are all through. That represents its higher rigidity rating. Companies did pressure tests on latches to mention that, what sort of crazy burden-bearing limit these stainless steel machine screws have. Stainless steel has a tensile PSI quality of 100,000 to 150,000. Hot Dipped galvanized screw has a rigidity of 62,000 PSI since they are grade 2 fasteners.

 

 

Material Tensile Strength Yield Strength
PSI MPa PSI MPa
Stainless Steel 100000-150000 689-1034 30000-40000 206-275
Galvanized Steel 38000-62000 262-427 21000-31000 144-213

Rusty Nature

The process of galvanization involves the application of a molten zinc coating onto a core of plain steel. While it is rare, the core of the screw may be exposed due to wear and tear over time.

In contrast, stainless steel screws are protected by their inherent chromium composition, which enables the formation of a passivation layer that provides excellent resistance to rust and corrosion. However, if the availability of oxygen is limited, such as in the presence of water, stainless steel screws may still corrode. Although such scenarios are relatively rare, it is essential to consider the potential risk of rusting in any application involving water and stainless steel screws.

Conclusion

Both have their distinct properties acquainted with their utility. Galvanized steel screw is cheaper than stainless steel screw but stainless steel screw is much more durable due to their anti-rust chromium property. This isn’t generally an immediate challenge. Galvanized screws have that solid, dull, mechanical look, while stainless steel is shinier and more refined looking. Thus, galvanized wins with regards to its cheap price, stainless steel with regards to quality, and rust insurance.

References

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