ชุดดอกสว่าน SHR-025-8920K

Sherwood Jobber Drills Steam Tempered HSS

Sherwood Jobber drills are general-purpose engineering drills for steels, cast steel, grey cast iron, malleable cast iron, nickel brass, aluminium alloy 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 passed over the product during a controlled tempering cycle, producing a black oxide layer. Black tools are generally recommended for ferrous applications where the 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. 

Point angle: 118, helix angle: normal, web thickness: standard, relief angle: 10-20, tolerance of diameter: h8, tolerance of shank: f11.
Suitable for drilling a wide range of different materials, all drills are ground flute industrial quality and will be blue finish unless otherwise requested. Manufactured to BS328:Part 1: 1986,DIN338RN.

ORDER CODE : SHR-025-8920K

•  Set contains: Metric:- 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0mm. Inch:- 1/16", 5/64", 3/32", 7/64", 1/8", 9/64", 5/32", 11/64", 3/16", 13/64", 7/32", 15/64", 1/4", 17/64", 9/32", 19/64", 5/16", 21/64", 11/32", 23/64", 3/8", 25/64", 13/32", 27/64", 7/16", 29/64", 15/32", 31/64" and 1/2". Gauge 1-60.