Tag: GDandT Symbol

GD&T Position
by GD&T Guy on December 22, 2014.

Position is one of the most useful and most complex of all the symbols in GD&T. The two methods of using Position discussed on this page will be RFS or Regardless of Feature Size and under a material condition (Maximum Material Condition or Least Material Condition). Position is always used with a feature of size.

by GD&T Guy on December 21, 2014.

GD&T Symbol:  Relative to Datum: No MMC or LMC applicable: No Drawing Callout: Description: The circularity symbol is used to describe how close an object should be to a true circle. Sometimes called roundness, circularity is a 2-Dimensional tolerance that controls the overall form of a circle ensuring it is not too oblong, square, or…

by GD&T Guy on December 20, 2014.

Special Note: Parallelism actually has two different functions in GD&T depending which reference feature is called out. The normal form or Surface Parallelism is a tolerance that controls parallelism between two surfaces or features. The surface form is controlled similar to flatness with two parallel planes acting as its tolerance zone. Axis Parallelism is a tolerance…

GDT Symbol cylindricity
by GD&T Guy on December 18, 2014.

GD&T Symbol: Relative to Datum: No MMC or LMC applicable: No Drawing Callout: Description: The Cylindricity symbol is used to describe how close an object conforms to a true cylinder. Cylindricity is a 3-Dimensional tolerance that controls the overall form of a cylindrical feature to ensure that it is round enough and straight enough along…

GD&T Symbols Profile of a surface
by GD&T Guy on December 18, 2014.

GD&T Symbol:  Relative to Datum: Optional MMC or LMC applicable: No Drawing Callout: Description: Profile of a surface describes a 3-Dimensional tolerance zone around a surface, usually which is an advanced curve or shape. If it is called out on a curved surface, like a fillet on a welded part, the entire surface where the radius…

RUNOUT circular GD&T symbol
by GD&T Guy on December 16, 2014.

GD&T Symbol:  Relative to Datum: Yes MMC or LMC applicable: No Drawing Callout: Description: Runout is how much one given reference feature or features vary with respect to another datum when the part is rotated 360° around the datum axis. It is essentially a control of a circular feature, and how much variation it has…