Fiberglass gaskets are classified in sub-heading 7019.90 which provides for glass fibers (including glass wool) and articles thereof.
The Section XVII Note 2(a) exclusion for joints, washers or the like precludes gaskets of any material from classification in any of the provisions of that Section. Note 1-c of Chapter 84 states that the Chapter does not cover machinery, appliances or other articles for technical uses or parts thereof, of glass (heading 7019 or 7020). Therefore, fiberglass gaskets for use in the goods of Section XVII (i.e. Motor vehicles, transportation vehicles etc.) or in the goods of Chapter 84 would be classifiable in subheading 7019.90 rather than elsewhere in the tariff.
A fiberglass gasket that is solely or principally used as a part of an article in Chapter 85 or Chapter 90 is classifiable in the appropriate provision for parts.
HQ 089425 (i.e. US Ruling), dated September 26, 1991, classified oven door gaskets made from fiberglass, reinforced with steel wire mesh and coated with silicone, and used for domestic and commercial bake ovens, as articles of glass fibers in subheading 7019.90.50, HTSUS. The gasket was not classified as a part because gas ovens and parts thereof are classifiable in Chapter 84, and articles of fiberglass are precluded from classification in any of the provisions of Chapter 84. However, a fiberglass gasket for a domestic microwave oven would be classifiable in subheading 8516.90.50, HTSUS, and a fiberglass gasket for a domestic electric cooking range would be classifiable in subheading 8516.90.80, HTSUS.