What Is The Ideal Stainless Steel Grade For Water Bottles? 304，316，304L or 306L

There are many stainless steel insulated water bottles on the market. Do you know their material composition in detail? When choosing a stainless steel water bottle, the grade of stainless steel is a key factor. Common stainless steel grades include 304, 316, 304L and 316L. They each have different characteristics and advantages. Understanding the differences between these stainless steels can help you choose the stainless steel insulated water bottle that best suits your needs. As a professional stainless steel vacuum insulated water bottle manufacturer from China, we have extensive knowledge about these materials. In this article, we will discuss the characteristics of these materials in detail to help you choose the right and qualified stainless steel insulated water bottle, and give reasonable suggestions on the use and maintenance of stainless steel insulated water bottles.

SS304 Stainless Steel Water Bottle

304 stainless steel is the most widely used material on the market. It is known for its good corrosion resistance and high strength. It does not contain harmful substances such as lead and cadmium and fully complies with health standards. It is very suitable as a material for water bottles and drinking water bottles. There is absolutely no need to worry about harmful substances dissolving into the water.
The corrosion resistance of 304 stainless steel is quite good, it can resist general acid and alkali corrosion, and it is not easy to rust. Thinking about our daily drinking water environment, whether it is a home kitchen or an office, 304 stainless steel water bottles can easily cope with it. Moreover, its processing performance is also very good, and it can be made into water cups or kettles of various shapes. The surface is smooth and it is particularly convenient to clean.

But not all 304 stainless steel is food grade. 304 food grade stainless steel must pass the corresponding food safety test. In China, 304 food grade stainless steel must comply with the safety test of GB 4806.9-2016 national food safety standard. In the United States, 304 food grade stainless steel (FDA) is subject to the 21 CFR 177.2600 standard. When buying a thermos cup, you should also pay attention to whether the outer packaging, instructions, etc. indicate that the material has passed the corresponding national food safety standard. If not, you can ask the seller to show the quality inspection report for further inspection.

SS316 Stainless Steel Water Bottle

316 stainless steel is a more advanced material. 316 stainless steel adds molybdenum to 304 stainless steel, which further improves its corrosion resistance. Especially in environments containing chlorides, such as coastal areas and swimming pools, 316 stainless steel is more corrosion-resistant and less prone to rust. Moreover, the strength and hardness of 316 stainless steel are also higher than 304 stainless steel, and it is less likely to deform. This means that if you often need to carry a water cup when traveling, or the water cup is often bumped, 316 stainless steel will be a more durable choice.

Of course, 316 stainless steel has a wider range of applications. Due to its stronger heat resistance, low temperature resistance and corrosion resistance, 316 stainless steel can perform well in some high temperature, low temperature or corrosive occasions. Compared with 304 stainless steel, the price of 316 stainless steel is indeed higher. If you have a higher budget and pursue a higher quality of life, then 316 stainless steel water cups are definitely worth your possession.

Is 316 Material Really Better Than 304 Material?

316 is of medical grade, while 304 is of edible grade.

304 stainless steel contains more than 18% chromium and more than 8% nickel, while 316 stainless steel contains up to 12% nickel, and 2% molybdenum is added, so 316 has better corrosion resistance and high temperature resistance than 304.

But in fact, this difference in advantage will only be revealed under extremely harsh conditions.
For example, heat treatment environments with temperatures of hundreds or thousands of degrees, high-intensity corrosion environments, high-tech fields such as equipment used in seawater, chemistry, dyes, papermaking, oxalic acid, and fertilizers.

But as a daily necessity, stainless steel thermos cups are mostly used to hold white water, and the highest temperature of water is only 100℃. In this case, there is not much difference in the performance of 304 and 316.

The price of 316 stainless steel water bottles is often more expensive than that of 304 stainless steel water bottles, so when choosing stainless steel water bottles, it is enough to choose food-grade 304 stainless steel. Although it is not recommended to use stainless steel thermos bottles to store juice, coffee and other beverages that are easy to corrode stainless steel, if you really need to store coffee in a stainless steel bottle, then I would recommend that you choose a 316 stainless steel bottle with good corrosion resistance.

Are 304L and 316L materials better than 304 and 316?

The “L” in 304L and 316L stands for “Low”, which means low carbon steel.

The carbon content of 304 is not higher than 0.08%, and the carbon content of 304L is not higher than 0.03%. In most cases, there is basically no difference in the corrosion resistance and heat resistance of these two materials;

However, when performing some heat treatments up to 800 or 900 degrees, non-low carbon steel may cause intergranular corrosion, reducing the mechanical strength of the metal. In this case, it is more appropriate to use 314L and 316L. Low carbon steel is mainly used in the production of outdoor open-air machines in the chemical, coal, and petroleum industries with high requirements for resistance to intergranular corrosion. The choice between 304L and 304 is primarily a consideration for the chemical industry and is generally not a factor in stainless steel water bottle manufacturing.

For daily use of stainless steel insulated water bottles, the maximum temperature of the boiling water we add is 100 degrees Celsius, and the characteristics of 304L or 316L are not needed at all. Therefore, it is unnecessary to spend more money to buy 304L or 316L stainless steel insulated water bottles.

Accessories Material Of Insulated Water Bottle

The inner liner of the stainless steel thermos is food grade 304 stainless steel or 316 stainless steel, and the materials of other accessories of the thermos are also very important.

For example, the lid of the thermos must be made of edible PP material, such as tritan or ppsu. PC material is not recommended. Because the thermos is filled with hot water, under the action of water vapor for a long time, the plastic of PC material is likely to release bisphenol A. In addition, the straw and rubber plug of the cup must be made of food grade silicone. The main inspection standards for food grade silicone are FDA and LFGB. Qualified silicone is free of odor, dirt and normal color. If there is a clear pungent odor, please do not buy it.

Can A Stainless Steel Water Bottle Be Used For Beverages?

We often hear such a statement, which roughly means that 304 stainless steel insulated water bottles cannot hold other liquid materials except boiled water; 316 stainless steel insulated water bottles can hold various things such as milk, juice, and tea.

But on the other hand, there are often some articles telling us that using stainless steel insulated water bottles to hold tea, coffee, and juice drinks will precipitate harmful heavy metals. So, can insulated water bottle hold other liquids besides boiled water?

Most beverages are acidic or alkaline liquids. Stainless steel with high manganese content and low nickel content has poor corrosion resistance, is easy to rust and precipitate heavy metals, so it is not suitable for various types of acid and alkali liquids. For example, the manganese content of 201 industrial stainless steel is as high as 17%, and the nickel content is only 6%, which is a typical high manganese and low nickel material.

But 304 and 316 are actually stainless steel with high manganese content and low nickel content, and the nickel content of 316 is higher than that of 304, so theoretically, 316 is more suitable for acid and alkali liquids than 304.

On the other hand, food safety standards in most countries not only require food-grade stainless steel to meet certain criteria for corrosion resistance and high-temperature durability but also impose stringent limits on the leaching of five heavy metals: lead, chromium, nickel, cadmium, and arsenic.

Only insulated water bottles that have passed these heavy metal precipitation tests can be sold as qualified products on the market. Therefore, as long as you buy a qualified insulated water bottle produced by a regular manufacturer, whether it is 304 or 316, it can be used to hold beverages such as coffee and juice.

However, it is still not recommended to store acidic and alkaline beverages such as juice, coffee, and tea. It is recommended to use it only to store water. Why?
The above are the reasons:

1. Easy to breed bacteria: The thermos is very tightly sealed, easy to absorb odors, and difficult to remove. The smell of coffee and juice is likely to remain in the cup, and the thermos has more sanitary dead corners than ordinary water cups, which is too easy to hide dirt and breed bacteria.
2. Easy to corrode the liner: Some carbonated beverages contain a lot of gas, which causes the pressure inside the cup to increase in a sealed thermos, making the cup lid difficult to open or even explode; and carbonated beverages themselves contain acid, which may corrode the liner if placed in the thermos for a long time, reducing the life of the thermos.
3. Residual tea stains: Storing tea in a stainless steel thermos, soaking it in high temperature for a long time will only destroy the flavor and taste of the tea, and it is easy to leave tea stains in the cup, which is not easy to clean.

In view of the above reasons, in order to ensure the safety of your drinking water and the durability of the thermos, it is recommended to use it exclusively to hold plain water, so as to maximize the stability of the internal environment of the bottle and ensure that the water you drink is always safe and pure.

A Detailed Guide To Choosing And Buying A Quality Stainless Steel Insulated Water Bottle?

1.Purchase Through Formal Channels And Choose Well-Known Brand Products

If you are in the market for a stainless steel thermos, I would suggest going through the right channels to buy it such as large malls, authorized dealers or at their official flagship stores. This will not only make sure that the product is of high quality and has efficient after sales services but it will help you avoid buying of counterfeit products. Furthermore, pick a thermos from an established brand as these brands often go through rigorous quality testing, are well known in the market and have dependable product warranties.

2.Check The Material Type Of Stainless Steel Insulated Water Bottle

Be mindful of the product label and instructions when making a purchase so as to ascertain what kind of material it’s made of. For example, high-quality stainless steel thermos bottles usually indicate the austenitic stainless steel used, such as SUS304 or SUS316 stainless steel. Such marks can guide consumers on whether their acquisitions conform to food contact materials’ safety regulations.

3.Judging Product Quality By Smell

You should take the top off and smell if there is any weird smell, when you go shopping for thermos. Most of the times, these thermos are made of food grade materials which do not emit any strange smells. It indicates that perhaps this thermos cup is substandard if one can sense a strong smell of plastic or any other acrid odor that is perceived through the nose only.

4.Check The Smoothness Of The Surface Of The Insulated Water Bottle

Top-grade stainless steel thermos are made with utmost precision. Shoppers should inspect the thermos to see if its inner liner, outer wall and rim are free from scratches, dents or visible seams. Smooth and flawless surfaces tend to last longer during usage, accumulate fewer germs and are easy to clean.

5.Pay Attention To The Material Of Accessories Such As Sealing Rings And Straws

Sealing rings, straws, as well as other components of a thermos cup which have contact with liquids easily must contain food-grade silicone materials. Such materials should be heat resistant and elastic enough to preclude the creation of any toxic substances upon coming into contact with liquids and this will assure its safety when using it. Upon purchase you can clarify these accessories’ types from their product manual.

6.Test For Water Leakage And Thermal Insulation Performance After Purchase

Consumers are therefore advised to initially conduct basic tests on water leakage and heat preservation performance after acquiring a thermos. Hot water should be poured into the thermos, the lid tightly closed, and checked for any leaks. Checking on the change of temperature of the water after being left for a couple of hours can test the heat preservation performance. Most high quality thermoses have more than 6 hours of heat preservation time that guarantees their practicality and convenience in daily life.

Conclusion

Food-grade 304, 316 or 304L and 316L are all suitable as materials for stainless steel water bottles. In daily life, there is little difference between them. As a professional stainless steel insulated water bottle manufacturer, I recommend you to buy the most cost-effective 304 stainless steel water bottle. It is competent for most scenarios. Of course, if you live in an environment with higher corrosion resistance requirements such as the seaside, 316 stainless steel water bottle is a better choice. There are few 304L and 316L stainless steel water bottles on the market, and the price is relatively high. Their characteristics can be met by ss304 or ss316, so there is no need to buy them.

Of course, in addition to selecting the materials for stainless steel water bottles, it is also very important to learn to choose qualified products produced by regular manufacturers. I hope you get the stainless steel water bottle you want.

About MOYA

MOYA is leading vaccum insulated bottle manufacturer from China，we provide wholesale insulated water bottles and thermos flask.our wholesale insulated water bottles.Our wholesale insulated water bottles have more than 60 styles, including classic and trendy styles, with various capacities and sizes. As a professional vaccum insulated bottle manufacturer, we are committed to providing clients with the most comprehensive OEM & ODM custom insulated water bottle services. Here at MOYA, we can design a brand new insulated water bottle from 0 to 1 according to your ideas.
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