Rubber Washer Bolt Hexagon Socket Cap Head Black Galvanizing

Rubber washer bolt is a cap head bolt with a rubber washer under the head. The hex socket screw drive has a hexagonal recess and may be driven by a hex wrench, also known as an Allen wrench, Allen key, hex key or inbus as well as by a hex screwdriver (also known as a hex driver) or bit. Tamper-resistant versions with a pin in the recess are available.
The abbreviation “Inbus” is derived from “Innensechskant Bauer & Schurte”, analogous to the US use of “Allen key”. Ever Hardware provides custom-made fasteners and customizable packaging.

Galvanization, or galvanisation, (or galvanizing as it is most commonly called in that industry), is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which parts are submerged in a bath of molten zinc. Galvanizing protects in three ways:
It forms a coating of zinc which, when intact, prevents corrosive substances from reaching the underlying steel or iron.
The zinc serves as a sacrificial anode so that even if the coating is scratched, the exposed steel will still be protected by the remaining zinc.
The zinc protects its base metal by corroding before iron. For better results, the application of chromates over zinc is also seen as an industrial trend.