corrosion-proof
21Arc welding — uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point. They can use either direct (DC) or alternating (AC) current, and consumable or non consumable electrodes.… …
22Brass — For other uses, see Brass (disambiguation). Brass die, along with zinc and copper samples. Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.[1] In …
23Drilling fluid — This article is about fluids used when drilling a well. For fluids used with drill bits during metal working, see cutting fluid. Driller pouring a foaming agent down the rod string on a drilling rig In geotechnical engineering, drilling fluid is… …
24Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
25Wrought iron — is commercially pure iron. In contrast to steel, it has a very low carbon content. It is a fibrous material due to the slag inclusions (a normal constituent). This is also what gives it a grain resembling wood, which is visible when it is etched… …
26Heckler & Koch USP — Type Pistol Place of origin …
27Karabiner 98k — Karabiner 98 Kurz Karabiner 98 kurz Type Bolt action rifle Place of origin …
28Concrete — This article is about the construction material. For other uses, see Concrete (disambiguation). Outer view of the Roman Pantheon, still the largest unreinforced solid concrete dome.[1] …
29Platinum — This article is about the chemical element. For other uses, see Platinum (disambiguation). iridium ← platinum → gold Pd ↑ Pt ↓ Ds …
30Penny (United States coin) — Cent (Penny) United States Value 0.01 of a U.S. dollar Mass  2.5 g  (0.080 troy oz) Diameter  19.05 mm  (0.750 in) Thickness …
