Dec 14, 2017 · GD&T: Material Modifiers, what are they? How do they work? If you have been around part drawings and manufacturing long enough, there's a pretty good chance you've seen a feature control fame with a circled letter after the tolerance.

Material Modifiers provide one of three callouts that describe whether a feature contains the maximum or minimum amount of material when fabricated, thus affecting the overall tolerance of the feature. MMC - Maximum Material Condition. LMC - Least Material Condition. RFS - Regardless of Feature of Size.

When should we use MMC (Maximum Material Condition), LMC (Least Material Condition) and RFS (Regardless of Feature Size)? What are the practical implications of these modifiers? This text emphasizes the relationship between material modifiers and fit conditions.

Least Material Condition (LMC) is the size of a feature of size for which the part contains the minimum amount of material. For an internal feature of size, the LMC size is the largest allowable size. For an external feature of size, the LMC size is the smallest allowable size.

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. For example, when a feature is designed to be fitted with another feature, such as a pin or a hole, the tolerances for the size and position affect the result.

Dec 13, 2014 · 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.

Maximum Material Condition (MMC) and Least Material Condition (LMC): Simple Definitions. 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.

What are Material condition modifiers? GD&T on holes (and shafts) provides a powerful tool for increasing inspection yield without trial-and-error fitting or binning. Used when the size of the feature interacts with its location.

Jun 25, 2024 · How do you know when to use the MMC and MMB modifiers? To answer this question, Jason reviews the example drawing, below, of a simple part that uses the MMB and MMC modifiers, explaining why these modifiers can only be applied to a feature of size.

GD&T is a set of rules and symbols describing a part’s nominal geometry and the permissible variation range. It emphasizes the part’s function and parts assembly, allowing for larger tolerances on less critical design features. This approach can …