Flatness (manufacturing)

In <a href="/facts/Manufacturing/3qW7bcdy">manufacturing</a> and <a href="/facts/Mechanical_engineering/cbId4fye">mechanical engineering</a>, flatness is an important geometric condition for <a href="/facts/Workpiece/ws4oSvXv">workpieces</a> and <a href="/facts/Machine_tool/XPHaqz0p">tools</a>. Flatness is the condition of a surface or derived median plane having all elements in one plane.
<a href="/facts/Geometric_dimensioning_and_tolerancing/xlfqadu6">Geometric dimensioning and tolerancing</a> has provided geometrically defined, quantitative ways of defining flatness <a href="/facts/Operational_definition/CDnIenDo">operationally</a>.
Flatness deviation may be defined in terms of <a href="/facts/Least_squares_fit/50jIwbxC">least squares fit</a> to a plane ("statistical flatness") or worst-case (the distance between the two closest parallel planes within). It can be specified for a given area and/or over an entire surface. 
In the manufacture of precision parts and assemblies, especially where parts will be required to be connected across a surface area in an <a href="/facts/Hermetic_seal/N4W2PQnS">air-tight</a> or <a href="/facts/Waterproofing/xAmUoTUG">liquid-tight</a> manner, flatness is a critical quality of the manufactured surfaces. Such surfaces are usually <a href="/facts/Machined/Yrjfj6IV">machined</a> or <a href="/facts/Grinding_operations/r60I0Y5Y">ground</a> to achieve the required degree of flatness. Metrology of such a surface can confirm and ensure that the required degree of flatness has been achieved as a key step in a manufacturing processes. 
Two parts that are flat to about 1 <a href="/facts/Helium_light_band/CXVRF336">helium light band</a> (HLB) can be "wrung" together, which means they will cling to each other when placed in contact. This phenomenon is commonly used with <a href="/facts/Gauge_blocks/nm9znRk8">gauge blocks</a>.

Flatness (manufacturing) open-in-new

Flatness (manufacturing)