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:'''L''' die hoekmomentumvektor is
:t staan vir tyd.
Die gevolg van beide hierdie definisies is dat wringkrag 'n vektor is, wat in die rigting van die as van die draaibeweging wat dit sal veroorsaak.
==Eenhede==
Wringkrag het dimensies van krag vermenigvuldig met [[afstand]] en die [[SI|SI-eenhede]] van wringkrag word geskryf as "[[newton meter]]" (N m of N·m).<ref name="BIPM 5.1">SI Brosjure Weergawe 8, Afdeling 5.1, Bureau International des Poids et Mesures, 2006, [http://www1.bipm.org/en/si/si_brochure/chapter5/5-1.html], afgelaai 2007-04-01</ref>
Die [[joule]] is die SI-eenheid vir [[energie]] of [[meganiese werk|werk]] en kan ook uitgedruk word as N·m, joule word egter nie gebruik om wringkrag uit te druk nie. Aangesien 'n mens aan energie kan dink as die dotproduk van krag en afstand is energie altyd 'n skalaar terwyl wringkrag die kruisproduk is van krag en afstand en is 'n [[pseudovektor]] grootheid.
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As a consequence of either of these definitions, torque is a [[vector]], which points along the axis of the rotation it would tend to cause.
==Units==
Torque has dimensions of force times [[distance]] and the [[SI]] units of torque are stated as "[[newton metre]]s" (N m or N·m).<ref name="BIPM 5.1">{{cite web | title = SI brochure Ed. 8, Section 5.1 | publisher = Bureau International des Poids et Mesures | date = 2006 | url = http://www1.bipm.org/en/si/si_brochure/chapter5/5-1.html | accessdate = 2007-04-01}}</ref> Even though the order of "newton" and "metres" are mathematically interchangeable, the BIPM ([[Bureau International des Poids et Mesures]]) specifies that the order should be N·m not m·N.<ref name="BIPM 2.2.2">{{cite web | title = SI brochure Ed. 8, Section 2.2.2 | publisher = Bureau International des Poids et Mesures | date = 2006 | url = http://www1.bipm.org/en/si/derived_units/2-2-2.html | accessdate = 2007-04-01}}</ref>
The [[joule]], which is the SI unit for [[energy]] or [[mechanical work|work]], is also defined as 1 N·m, but this unit is not used for torque. Since energy can be thought of as the result of "force dot distance", energy is always a scalar whereas torque is "force cross distance" and so is a [[pseudovector|(pseudo) vector]]-valued quantity. Of course, the dimensional equivalence of these units is not simply a coincidence; a torque of 1 N·m applied through a full revolution will require an [[energy]] of exactly 2π joules. Mathematically,
:<math>E= \tau \theta\ </math>
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