If the Flatness with Figure B is given, there is a restriction that it should be manufactured within 0.02mmĮven if irregularities occur as shown in the figure on the right of Figure D.Īccordingly, a flat component surface desired by the designer If no Flatness GD&T is applied, uneveness may occur as shown in Figure C, resulting in unwanted defective products. To the bottom surface as shown in Figure B. To be manufactured flat, Flatness GD&T must be applied

In this case, in order for the bottom surface of the component For example, let's say we manufacture parts as shown in Figure A.įor production, drawings must be prepared as shown in Figure B below. It is used to make certain surfaces of the parts flat to the desired level. Reasons for use and examples and methods of marking. That is, the tolerance indicated in the drawing to what extent (mm or micrometer) of unevenness is used on the plane.ī. Tolerance indicated in the drawing how flat the plane of the part should be made.

(Note that the Geometric Tolerance is basically a symbol used in the drawing of the part.) In this posting, we will look at Geometric Tolerance( Geometric Dimensioning and Tolerancing, GD&T),Įspecially Flatness and Parallelism (definition, reason for use),Īnd distinguish between the two concepts.

Symbol for flatness on a drawing