What is MMC size?
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.
What is MMC GD and T?
In GD, maximum material condition (MMC) refers to a feature-of-size that contains the greatest amount of material, yet remains within its tolerance zone. Some examples of MMC include: Largest pin diameter. Smallest hole size.
What is MMC true position?
material conditions
True Position using material conditions (MMC/LMC) True position with a feature of size can control the location, orientation and the size of the feature all at once. MMC true position is helpful for creating functional gauges that can be used to quickly insert into the part see if everything is within spec.
How do you calculate clearance hole size?
The LMC clearance hole also can be calculated by adding the diameter of the fastener and the diameter of the fastener head and then dividing the sum by two. This method of selecting the LMC clearance hole size is a rule of thumb that will yield the largest hole that will fit under the head of the fastener.
How do you calculate virtual size?
Virtual Condition = Tolerance boundary that is constant for all sizes and generated by the cumulative effects of size and geometric tolerance at MMC. For an external feature of size with MMC specified, Virtual Condition = MMC + Geometric tolerance, or as-manufactured size + allowed geometric tolerance at that size.
What is bonus tolerancing?
In GD, bonus tolerance is a modification of a GD 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 tolerance, bonus tolerance becomes available.
How is virtual condition calculated?
What is clearance hole?
Filters. A hole through an object which is large enough to enable threads of a screw or bolt to pass through but not the head of the screw or bolt. noun.
What size bolt fits in a 7/16 hole?
Minimum Clearance Hole Diameters
| Bolt Size | Bolt Dia. [in] | Normal Fit [in] |
|---|---|---|
| 1/4″ | 0.2500 | 0.281 |
| 5/16″ | 0.3125 | 0.344 |
| 3/8″ | 0.3750 | 0.406 |
| 7/16″ | 0.4375 | 0.469 |
How does GD calculate virtual size?
The calculations for the Virtual Condition are shown below:
- Virtual Condition (internal feature) = MMC (smallest size) – Geometric Tolerance.
- Virtual Condition (external feature) = MMC (largest size) + Geometric Tolerance.
- Inner Boundary @ RFS = Smallest Feature Size – Geometric Tolerance.
What is maximum material condition (MMC) in GD?
What is Maximum material condition (MMC) in GD? In Design of any machine elements, it is necessary to follow the Geometric dimensioning and tolerancing for the Holes or shafts.
How do you calculate GD position tolerance?
Diametrical Actual Tolerance = 2 X under root (0.15) square + (0.00) square. Therefore actual GD Position Tolerance measured against 0.25 is 0.30. The part is rejected. Now calculate bonus tolerance = ( LMC Diameter – Actual Diameter ) = (4.20 – 4.10) = 0.10
What does MMC mean in dimensioning?
Maximum Material Condition (MMC) This is a condition where there exists a maximum amount of material within the given dimension tolerance zone. Maximum Material Condition is one side of the dimensional limits on a part. The other side of the tolerance range would be the Least Material Condition.
How to find the excess tolerance or tolerance deficit in MMC?
With the specified true position and T value, you can figure out the excess tolerance or tolerance deficit value using the below true position tolerance MMC formula. True position tolerance MMC is used as a geometric dimensioning and tolerancing (GD) location control over the electrical engineers design and drawings.