Double Ended Insert Screws Hexagon Socket Threaded Black Bolts

Double ended insert screws have the same length threads on each end usually to house a nut. Both ends have chamfered points. A stud is upright support in the wall of a building to which sheathing, drywall, etc., are attached. Ever Hardware provides custom-made fasteners and customizable packaging.

Black oxide or blackening is a conversion coating for ferrous materials, stainless steel, copper and copper-based alloys, zinc, powdered metals, and silver solder. It is used to add mild corrosion resistance, for appearance and to minimize light reflection. To achieve maximum corrosion resistance the black oxide must be impregnated with oil or wax. One of its advantages over other coatings is its minimal buildup.

12.9-grade steel means that a component manufactured form this grade of steel has 12X100 N/mm^2 tensile strength and 9 is a multiplier means 90% of 1200 = 1080 N/mm^2 is the yield strength of the grade.
Similarly, we also have grade 8.8, 10.9, 6.8 also. This is the imperial method implied by engineers to differentiate between different sets of steel grades. Mainly used to differentiate the bolts and nuts. like Grade 12.9 Hexagonal Bolt.

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