114pcs HSS GroundFluteJobberDrill

Specification of 114pcs HSS GroundFluteJobberDrill

Sherwood HSS Jobber Drill Ground Flute Set-114 Pieces

Sherwood Jobber drills are general-purpose drills for steels, cast steel, grey cast iron, malleable cast iron, brass, aluminium alloy of nickel and graphite. With precision-ground flutes and black finish (W-finish), this is the most common surface finish and is the result of a steam tempering operation in which steam is just passed over the product during a controlled tempering cycle, producing a black oxide layer. Black tools aregenerally recommended for applications where the ferrous oxide layer aids chip flow, helps to dissipate heat by retaining some coolant on the tool surface and also helps to prevent the tool from staining.

HSS Jobber Drill Ground Flute Set-114 Pieces
Industrial quality. Ground flute, blue finish. Supplied in indexing metal cases.
Point angle: 118, helix angle: normal, web thickness: standard, relief angle: 10-20, tolerance of diameter: h8, tolerance of shank: f11.