From the official SI websiteArchived 2021-04-19 at the Wayback Machine, The International System of Units – 9th edition – Text in English Section 2.3.4: "For example, the quantity torque is the cross product of a position vector and a force vector. The SI unit is newton-metre. Even though torque has the same dimension as energy (SI unit joule), the joule is never used for expressing torque."
Page, Chester H. (1979). "Rebuttal to de Boer's 'Group properties of quantities and units'". American Journal of Physics. 47 (9): 820. Bibcode:1979AmJPh..47..820P. doi:10.1119/1.11704.
grainger.com
"Dial Torque Wrenches from Grainger". Grainger. 2020. Demonstration that, as in most US industrial settings, the torque ranges are given in ft-lb rather than lbf-ft.
Page, Chester H. (1979). "Rebuttal to de Boer's 'Group properties of quantities and units'". American Journal of Physics. 47 (9): 820. Bibcode:1979AmJPh..47..820P. doi:10.1119/1.11704.
From the official SI websiteArchived 2021-04-19 at the Wayback Machine, The International System of Units – 9th edition – Text in English Section 2.3.4: "For example, the quantity torque is the cross product of a position vector and a force vector. The SI unit is newton-metre. Even though torque has the same dimension as energy (SI unit joule), the joule is never used for expressing torque."
