Выражения встречаются в контексте описания компании, занимающейся производством различных вариантов стальных труб. Видимо, какие-то виды продуктов или услуг.

Конкретный абзац:
Its products include steel pipes and its variants, such as high pressure resistant steel pipes, galvanized zinc-coated steel pipes, cold castings and bolted joints, as well as fabricated steel structures and steel frames for construction purposes. The Company is also involved in steel casting, stainless steel coating, construction and freight transportation.

Заранее спасибо