M4-0.7 Hex Socket Tip Point Set Screw DIN 914 Steel Black Oxide 45H

Description

M4-0.7 Hex socket tip point set screw is a type of screw generally used to secure an object within or against another object, normally not using a nut. The most common examples are securing a pulley or gear to a shaft. Set screws are usually headless (also called blind), meaning that the screw is fully threaded and has no head projecting past the major diameter of the screw thread. If a set screw has a head, the thread will extend all the way to the head (whereas a bolt might have an unthreaded shank between the head and thread). A blind set screw (known in the UK as a grub screw, quite possibly from its figurative resemblance to a soil-dwelling grub) is almost always driven with an internal-wrenching drive, such as a hex socket (Allen), star (Torx), square socket (Robertson), or slot. The set screw passes through a threaded hole in the outer object and is tightened against the inner object to prevent it from moving relative to the outer object. It exerts compressional or clamping force through the bottom tip that projects through the hole. Ever Hardware provides custom made fasteners and customizable packaging.

45H equals Grade 12.9, 12.9-grade M4-0.7 hex socket tip point set screw 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 an 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.
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.
The five basic steps for the black oxide conversion coating are clean; rinse; black oxide; rinse; supplementary coating (after-finish). If rust or scale is present on the part, additional steps such as acid pickling or alkaline de-scaling may have to be added before oxidizing. Neutralizing and/or further rinsing may be necessary on assemblies and parts with blind holes to eliminate “flowering” or bleed-out. Black oxide cannot be produced over plated parts (zinc, nickel, chromium, cadmium, phosphate). This plating must be stripped prior to the black oxide process.