Countersink


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countersink

[′kau̇nt·ər‚siŋk]
(design engineering)
The tapered and relieved cutting portion in a twist drill, situated between the pilot drill and the body.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Countersink

 

(Russian, zenkovka; from German senken, “to sink, lower”), a cutting tool used for countersinking. Countersinks usually form part of a set with centering drills. The sizes of countersinks in each set depend on the diameter of the hole; in all sets, the vertex angle is 60°. Coun tersinks are made for chamfering center holes with diameters of 0.5 to 1.5 mm (ordinary countersinks), for holes with diameters of 0.5 to 6 mm (with or without protective taper), and for holes with diameters of 8 to 12 mm (with tapered stem). Countersink cutting elements are made from high-speed steel; countersinks with tapered stems are welded and the stems are made from carbon structural steel.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

countersink

countersink
A boring bit having a conical-shaped cutter; used to make a depression to receive the head of a screw or bolt so that it does not protrude above the surface.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
To accomplish the countersink in the others cases (C2 and 3), deformed shape of workpiece shows that the punch pushed the material towards the free regions as shown in Fig.
YOU can drill a pilot hole with a standard drill bit, then create a recess for the screw head with a countersink cutter.
Draw lines 2 inches and 18 1/2 inches from the bottom, then countersink 1 1/4-inch deck screws along these lines 3/4 inch from each edge of each board.
Use hole saw to countersink rail ends; customize fits as needed.
Due to our extensive product development efforts, we've combined several unique features, such as our POWERBOLIC[R] bit design, to ensure that the SMART-BIT quickly and easily produces the proper countersink every time."
The TIPO C25 has been specially developed to process sheet materials from 1.00mm to 25mm with the facility to punch, mill, drill, countersink, tap, ream, mark and high definition plasma-cut, all in the one processing cycle.
8 screws, then drill, countersink and screw the shelving onto the fillets using 11 2" No.
If you don't drill a countersink recess, the screw head may snap off before it sinks into the MDF.
The new Cham-Bit has a two-part design that allows simple re-sharpening of the countersink body while the drill is removed, and has the ability to lengthen small diameter drills while increasing rigidity and maintaining accuracy.
To assemble the cabinet, drill and countersink the fixings for the two side piece into the worktop, and attach using one and a half inch No.