Glass; unworked, in tubes, of fused quartz or other fused silica

HS v2022 Code: 700231

About glass; unworked, in tubes, of fused quartz or other fused silica

HS code 700231 covers the import and export of unworked glass tubes made from fused quartz or other fused silica. This type of glass is highly valued for its exceptional heat resistance, chemical stability, and optical properties, making it a crucial material in various industries, including electronics, scientific equipment, and specialized lighting. The global trade in fused silica glass tubes plays a significant role in supporting technological advancements and enabling the production of a wide range of essential products.

Production process

The production of fused silica glass tubes typically involves a multi-step process. First, high-purity quartz or other silica-rich raw materials are melted at extremely high temperatures, often exceeding 2,000°C. The molten glass is then formed into tubes through a process called drawing, where the glass is pulled through an orifice to create the desired diameter and wall thickness. The tubes may undergo additional processing, such as annealing or surface treatments, to enhance their properties and ensure consistent quality.

Production inputs

The primary raw material for the production of fused silica glass tubes is high-purity quartz or other silica-rich minerals. Specialized furnaces and drawing equipment are also essential inputs for the manufacturing process. Additionally, the industry relies on skilled labor, energy sources, and various support services to ensure efficient and consistent production.

Production outputs

The primary output of HS code 700231 is unworked fused silica glass tubes, which are then used as inputs for a wide range of applications. These tubes may be further processed or incorporated into products such as 701931 Glass; tubing, of fused quartz or other fused silica, unworked, 854390 Parts of electrical apparatus for line telephony or line telegraphy, and 901380 Optical devices, appliances and instruments, n.e.c. in chapter 90.

Revisions to 700231

Classification codes are adjusted frequently. The code may have been revised or replaced between system versions. The table below shows the history (newest to oldest) of the code 700231. The most recent 1 version of this code (700231) is in the HS v2022 system (this version):

This page shows the most recent version of code 700231.

Family tree for glass; unworked, in tubes, of fused quartz or other fused silica

    graph LR
    A["<a href='/classifications/hs/v2022/70'>70: Glass and glassware</a>"]
A --> B["<a href='/classifications/hs/v2022/7002'>7002: Glass in balls (other than microspheres of heading no. 7018), rods or tubes, unworked</a>"]
B --> C["<a href='/classifications/hs/v2022/700231'>700231: Glass; unworked, in tubes, of fused quartz or other fused silica</a>"]

    B --> D["<a href='/classifications/hs/v2022/700210'>700210: Glass; unworked, in balls (other than microspheres of heading no. 7018)</a>"]
B --> E["<a href='/classifications/hs/v2022/700220'>700220: Glass; unworked, in rods</a>"]
B --> F["<a href='/classifications/hs/v2022/700232'>700232: Glass; unworked, tubes, of glass having a linear coefficient of expansion not exceeding 5 x 10 (to the minus 6), (or 0.000005) per Kelvin within a temperature range of 0-300 degrees C</a>"]
B --> G["<a href='/classifications/hs/v2022/700239'>700239: Glass; unworked, in tubes, other than of glass having a linear coefficient of expansion not exceeding 5 x 10 (to the minus 6, (or 0.000005) ) per Kelvin within a temperature range of 0-300 degrees C, not fused quartz or other fused silica</a>"]

    

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