What is virtual condition in GD&T?

Virtual Condition is defined as the boundary generated by the collective effects of the specified MMC limit of size of a feature and any applicable geometric tolerance. For example, the MMC size of a shaft plus its axial Straightness tolerance, or the MMC size of a hole minus its Position tolerance.

What is virtual and resultant condition in GD&T?

There is a virtual condition (an inner boundary for a hole) that is equal to the MMC hole size minus the specifi ed position tolerance. A resultant condition (an outer boundary for a hole) is created by the LMC hole size plus the allowable position tolerance.

What is the best definition for virtual condition?

Virtual condition is the theoretical extreme boundary condition of a feature of size generated by the collective effects of MMC and any applicable geometric tolerances.

What is the virtual condition of the pin?

For an internal feature of size, such as a hole, the virtual condition is equal to the size at MMC minus the size of the tolerance zone. For the hole in Figure VC1. 2, the diameter of the virtual condition is the diameter of the MMC hole minus the diameter of the position tolerance zone. Figure VC1.2.

What is virtual and resultant conditioning?

For an external feature of size with MMC specified, Virtual Condition = MMC + Geometric tolerance, or as-manufactured size + allowed geometric tolerance at that size. Resultant Condition = Worst case tolerance boundary generated by the cumulative effects of size and geometric tolerance.

What is the use of virtual condition in GD&T?

The Virtual Condition of a feature is a concept used to describe the worst-case envelope which either of two features must lie within in order to mate acceptably. For a shaft that fits into a hole, the shaft virtual condition must be smaller than the hole virtual condition.

How do you find virtual conditions?

The calculations for the Virtual Condition are shown below:

1. Virtual Condition (internal feature) = MMC (smallest size) – Geometric Tolerance.
2. Virtual Condition (external feature) = MMC (largest size) + Geometric Tolerance.
3. Inner Boundary @ RFS = Smallest Feature Size – Geometric Tolerance.

What is LMC and MMC?

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 does MMC on datum mean?

MMC symbol next to a Datum (must be a feature of size also) = something completely different: it means you get to shift the tolerance zone over by the amount the Datum is over it's smallest allowed size.

What is MMC virtual condition Mcq?

What is MMC Virtual Condition? a) The collective effect of the MMC limit of size of a feature of size, and any applicable geometric tolerance.

What is MMC and LMC in GD&T?

Maximum material condition (MMC) is used to indicate tolerance for mating parts such as a shaft and its housing. Least material condition (LMC) is used to indicate the strength of holes near edges as well as the thickness of pipes.

What is feature of size?

“Feature of size” is the geometric shape defined by size dimensions such as length and angle. Examples of feature of size include cylindrical and spherical forms as well as two opposing planes. Since the feature is defined by size dimensions, the overall size changes along with the dimensions.

What is the best definition for virtual condition quizlet?

What is a virtual condition? A constant value of a worst-case boundary generated by the collective effects of a size feature specified at MMC or LMC material condition and the geometric tolerance for that material condition.

What is Max material condition?

Maximum Material Condition (MMC) exists when a part or feature contains the maximum amount of material everywhere, e.g. minimum size hole, or maximum size shaft.

What is a resultant condition?

Posted by John-Paul Belanger on Feb 13, 2008 in GD&T questions | 6 comments. If you are familiar with GD&T, you've probably heard of “virtual condition.” It is a number that represents a worst-case combination of a feature's size along with its geometric tolerance.

What is material condition modifier?

Use material condition modifiers in GD&T measurements to specify how the tolerance zone is affected by other tolerances that apply to a feature or datum feature.

What is tolerance modifier?

For some geometric tolerances that are applied to a feature of size, you must specify a material condition modifier (MMC, LMC, or RFS per Rule #2) for the tolerance zone. Keep in mind that the MMC and LMC modifiers introduce a bonus tolerance to the specified tolerance zone.

What is the difference between MMC and MMB?

The MMC size is the largest size, and the MMB is the boundary perpendicular to datum [A]. The diameter of the MMB is equal to the MMC size plus the Perpendicularity tolerance.

What is a bonus tolerance?

In GD&T, bonus tolerance is a modification of a GD&T tolerance that under certain conditions increases the tolerance, hence the term “bonus”. More specifically, when the maximum material condition (MMC) symbol is used to modify a GD&T tolerance, bonus tolerance becomes available.

What are the 3 types of tolerances?

These are grouped into form tolerance, orientation tolerance, location tolerance, and run-out tolerance, which can be used to indicate all shapes.

What does RFS mean in GD&T?

Definition: Regardless of Feature Size (RFS) is the default condition of all geometric tolerances by rule #2 of GD&T and requires no callout. Regardless of feature size simply means that whatever GD&T callout you make, is controlled independently of the size dimension of the part.

How do you read position tolerance?

An example of position tolerance is shown below. The top figure shows the position symbol applied to two holes. The boxed symbols can be read "relative to datums A, B, and C, the position of these hole centers shall lie within a cylindrical tolerance zone of diameter 0.3".

How do you calculate MMC and LMC?

For an feature of size specified at MMC, Resultant Condition = LMC + Geometric Tolerance allowed. This is a single tolerance and size event.

What is floating fastener formula?

The location tolerance is equal to the difference between the diameter of the clearance hole and the diameter of the fastener. = . 020 + (. 285 – .

What is datum sequence?

1. The order in which datums are specified determines how a part is to be positioned while inspecting the controlled feature(s).