Copper carvings, Dnipropetrovsk region.

" Send applications to viber (operator Our professional managers will be happy to advise each client. Material: copper. Type of connection: direct connection. Copper x internal thread. The choice of fitting depends not only on the type and size of the section, but also on the suitable material that harmoniously joins the pipeline.
(//tractor-service.com)
Today, threaded fittings are made of copper, brass, steel, cast iron, and polypropylene, which is especially popular recently. Also, threaded connections made of different materials have individual operational properties.

For example, if it is necessary to build a highly resistant and anti-corrosion system, then affordable fittings for copper pipes are necessary; reliable cast iron threaded fittings and steel fittings are optimal for price/quality when planning main pipelines in industry; if aesthetic qualities are important in the first place, with necessarily high operational characteristics, then expensive brass fittings are used; but the most profitable, economical and no less reliable investment for home plumbing will be fittings for metal-plastic pipes. It should be noted the growing popularity of polypropylene fittings on the domestic market, which is due to their versatility, without losing excellent operational characteristics."