Due to the need for heat insulation, the thermos tumbler is divided into two layers, which are called the “outer tank” and the “inner tank”. Since the inner tank is in direct contact with the water or other beverage, the requirements for materials are more stringent, in this case, 304 stainless steel, the food grade material is often used. And 316 stainless steel,better material than 304 is not uncommon. For the outer tank, since it does not directly hold the water or other beverage, the material requirements are not as high as the inner tank. 201 stainless steel can be used as a qualified material for the outer tank. However, in recent years, more and more businesses and factories have begun to advertise their thermos cup and tumbler products as “double-layer 304” or even “double-layer 316”, which seems to be a thankless task.

304 composition is 18Cr-9Ni, which is the most widely used stainless steel and heat-resistant steel. It is used in food production equipment, general chemical equipment, nuclear energy, etc., and has good corrosion resistance. However, 201 stainless steel contains high manganese content, is prone to rust, and is not corrosion-resistant. The corrosion resistance of 316 is better than that of 304. In daily life, thermos cups will inevitably be stained with various liquids. The thermos cups with 304 and 316 outer walls have less loss due to bad contact and naturally have a longer service life.

In addition, it is also attractive to customers who pursue high-quality products. If you regard the thermos cup as a gift, you naturally hope that the quality of the product will get better and better. Perhaps many customers do not understand the difference between 304 stainless steel and 210 stainless steel, but as long as they are told that the quality of 304 is better than that of 201, they will undoubtedly choose the former, although this difference does not affect normal use and drinking water。

The last point is that the competition in the thermos cup market is becoming increasingly fierce. In order to make their products stand out among the many dazzling products, many businesses have to rack their brains to innovate, from various layers (glossy, matte, glitter, sublimation) to various accessories (straw, lid, handle) ) to various processes (laser, silk screen and 3d/uv), the various external modifications of the cup seem to have come to an end. Merchants who have not tasted the sweetness in these aspects choose to optimize the internal part of the cup, that is, the material, although This optimization is not as eye-catching as the former and the cost is higher, but in the current fierce competition environment, no features means being eliminated. “High quality” is easier to achieve than other features that require creativity to create.

All in all, though double “304” or double “316” means better quality, it doesn’t means they are the must, as a customer, we should choose products by our standards, for most of us, inner 304 stainless steel and outer 201 stainless steel is good enough.