Hand scraper

A hand scraper is a single-edged tool used to scrape metal or other materials from a surface.

[1] Three raw cast surface plates (plates that have been "seasoned" by having their residual stress relieved and receiving suitable surface treatments, but which remain unfinished), a flat scraper (as pictured at the top of the image), and a quantity of engineer's blue (or red lead) were all that was required in the way of tools.

[citation needed] Grinding and machining stresses the metal thermally and mechanically, while scraping and lapping do not.

[citation needed] Lapping and grinding do not achieve the long-distance flatness that scraping can, as they act on the entire surface rather than local high or low spots.

[citation needed] The oil film will instead be swept, away leaving nothing but bare metal and the risk of seizure.

Such frosting will increase oil retention but will also drastically reduce bearing area and capacity.

[citation needed] There is no possibility of achieving hydrodynamic bearing performance on normal sliding machine ways.