burr

burr

¹, bur

1. a washer fitting around the end of a rivet

2. a blank punched out of sheet metal

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burr

², buhr, bur

1. short for buhrstone

2. a mass of hard siliceous rock surrounded by softer rock

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

burr

[bər]

(botany)

A rough or prickly envelope on a fruit.

A fruit so characterized.

(metallurgy)

A thin, ragged fin left on the edge of a piece of metal by a cutting or punching tool.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

burr

1. A waste brick from the kiln which has been partially fused.

2. A batch of bricks fused together.

3. A rough or sharp edge left on metal by a cutting tool.

4. Same as burl, 1.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

burr

A type of metal damage in which the sharp, rough edge of a piece of metal is left when the metal is sheared, punched, or drilled. This type of damage is more common in case compressor blades.

An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Burr

 

(also called flash), a projection on the surface of a product that is being worked; it forms as a result of the extrusion of material into the gap along the joint of a tool (a die or a pair of rollers) or because of imperfect cutting of the billet. When metal is worked using other methods, burrs are formed only if the production process has not been adjusted properly or if a worn tool is used.

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Burr

 

in woody trees, a thickening or growth on the trunks, branches, or roots. Burrs result from the local thickening of tissues, apparently in response to irritation or damage to cambium cells and dormant buds by fungi, frost, fire, or mechanical injuries (blows, slashes). According to the external appearance and to the structure of the fibers, two types of burrs are distinguished: those with smooth surfaces and slightly wavy wood and those with uneven surfaces and knotty wood (burls). The former type develops on the trunks of all varieties of trees; on pines and firs such burrs have wavy and relatively broad annual rings and consist of short thick-walled tracheids with curved or separated ends and of numerous large heartwood rays. The wood of burrs is much denser and harder than the ordinary trunk wood. Depending on dimensions and texture, burr wood may be used for producing structural ornament or for small household and artistic objects.

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