Turned, ground, and polished

{{Use mdy dates|date=January 2022}}

Turned, ground, and polished (TGP) is a classification of finishing processes often used for metal shafting. Turning (on a lathe) creates straight round bars without the strain induced by cold drawing, while grinding and polishing improves the surface finish and roundness for high dimensional accuracy.{{Cite web |url=http://www.amcastle.com/pdfs/carbonbar.pdf |title=Cold Finished Carbon Steel Bars: Quik Guide |publisher=Castle Metals |access-date=September 3, 2013 |archive-url=https://web.archive.org/web/20121224040137/http://www.amcastle.com/pdfs/carbonbar.pdf |archive-date=December 24, 2012 |url-status=dead}} Extreme straightness is critical in high-speed applications to prevent vibration and reduce wear on bearings.{{Cite web | url=http://www.speedymetals.com/s-101-turned-ground-polished.aspx |publisher=Speedy Metals |title=1045 Steel Round, Turned, Ground & Polished |access-date=January 7, 2022}}