# What is true position GD&T?

**GD&T**uses a notion called

**True Position**when tolerancing locations. There are two forms of

**True Position**–one for a feature size under a material condition (Maximum Material Condition or Least Material Condition), and one for

**True Position**Regardless of Feature Size (RFS).

A.

### What is the position tolerance?

**Position Tolerance**(symbol: ?) is a geometric dimensioning and tolerancing (GD&T) location control used on engineering drawings to specify desired location, as well as allowed deviation to the

**position**of a feature on a part.

#### What is meant by tolerance of form?

**Form Tolerance**- A**form tolerance**states how far an actual surface is permitted to vary from desired geometric**form**. Expressions of these**tolerances**refer to limits of size, flatness, straightness, parallelism, perpendicularly, angularity, roundness, cylindricity, profile of a surface and profile of a line.#### What is the symbol of flatness?

**GD&T**Flatness is very**straight**forward. It is a common symbol that references how**flat**a surface is regardless of any other datum's or features. It comes in useful if a feature is to be defined on a drawing that needs to be uniformly**flat**without tightening any other dimensions on the drawing.#### What is the parallel?

an imaginary circle on the earth's surface formed by the intersection of a plane**parallel**to the plane of the equator, bearing east and west and designated in degrees of**latitude**north or south of the equator along the arc of any meridian. the line representing this circle on a chart or map.

B.

### What is GD&T tolerance?

Geometric Dimensioning and Tolerancing (

**GD&T**) is a system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and computer-generated three-dimensional solid models that explicitly describes nominal geometry and its allowable variation.#### What is MMC and LMC?

**MMC**is the condition of a feature which contains the maximum amount of material, that is, the smallest hole or largest pin, within the stated limits of size.**LMC**is the condition in which there is the least amount of material, the largest hole or smallest pin, within the stated limits of size.#### What is GD&T?

Geometric Dimensioning and Tolerancing (**GD&T**) is a system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and computer-generated three-dimensional solid models that explicitly describes nominal geometry and its allowable variation.#### What is GDT used for?

**GD&T**stands for Geometric Dimensioning and Tolerancing. It is a system of symbols, rules and definitions used to define the geometry of mechanical parts.**GD&T**is one of the most powerful tools available that can improve quality, reduce cost and shorten delivery time.

C.

### What is MMC and LMC?

**MMC**is the condition of a feature which contains the maximum amount of material, that is, the smallest hole or largest pin, within the stated limits of size.

**LMC**is the condition in which there is the least amount of material, the largest hole or smallest pin, within the stated limits of size.

#### What is LMC of a hole?

Definition: Least material condition is a feature of size symbol that describes a dimensional or size condition where the least amount of material (volume/size) exists within its dimensional tolerance. The callout also overrides**GD&T**Rule#2 or the Regardless of Feature Size rule.#### What is a feature of size?

In GD&T the term**feature-of-size**(FOS) refers to any surface, or set of parallel surfaces associated with a**size**dimension. Specific examples of**features of size**include: A hole diameter (a cylindrical surface) Plate thickness (two opposed parallel surfaces)#### What is the meaning of material condition?

Definition: Maximum**Material Condition**or for short, MMC, is a feature of size symbol that describes the**condition**of a feature or part where the maximum amount of**material**(volume/size) exists within its dimensional tolerance.

Updated: 2nd October 2019