Regardless of Feature Size Explained
By Lucas Lo | Updated: Sep. 03, 2025
Table of Contents
In Geometric Dimensioning and Tolerancing, there are three kinds of main material modifiers, including Regardless of Feature Size, Maximum Material Condition, and Least Material Condition.
This article will comprehensively explain definition of GD&T Regardless of Feature Size.
1. What is Regardless of Feature Size in GD&T?
In Geometric Dimensioning and Tolerancing(GD&T), Regardless of Feature Size is a kind of controlling condition for geometric tolerances.
Regardless of Feature Size defines that the controls of all geometric tolerances within the feature control frame of a specific feature are totally independent from the feature’s actual size.
In other word, no matter how much the actual size of the controlled feature deviates from its basic dimension within the acceptable zone, the feature’s geometric tolerances are fixed and will not vary due to the actual size.
Regardless of Feature Size does not allow any bonus tolerance for geometries.
Regardless of Feature Size is usually easy to be ignored because it is the default condition of all geometric tolerances on engineering drawings according to the Rule #2 of ASME Y14.5.
It means that there is no specific symbol for Regardless of Feature Size, and if there is no any modifying symbol(such as Maximum Material Condition or Least Material Condition) specified within the feature control frame of the controlled feature, all geometric tolerances are controlled Regardless of Feature Size by default.
2. What are Functions of Regardless of Feature Size?
As a kind of tight and absolute tolerancing control condition, Regardless of Feature Size stands out in stability, reliability, and precision. The main functions of Regardless of Feature Size are as follows.
- Simplifying Engineering Drawings
As the default condition of all geometric tolerances(such as GD&T Position, GD&T Perpendicularity and GD&T Parallelism), Regardless of Feature Size works without indicational symbol on engineering drawings.
It effectively simplifies drawing indications and prevents design intent from being misunderstood, which helps to enhance communication efficiency and reduce cost.
- Eliminating Bonus Tolerance
Regardless of Feature Size would eliminate bonus tolerance. It keeps all indicated geometric tolerances constant and independent from dimension.
For instant, when a hole’s perpendicularity is under control of Regardless of Feature Size, whether the actual size of the hole is the maximum or minimum value within its allowable zone, the tolerance zone of the perpendicularity remains the same.
The change of the actual size would not provide bonus tolerance for the perpendicularity. Therefore, Regardless of Feature Size can ensure tight control on geometric tolerances.
- Ensuring Consistency of Key Geometric Functions
Since all geometric tolerances are irrelevant to actual dimension of the controlled feature under Regardless of Feature Size, it is commonly suitable for the parts that have high requirements on stability of geometric accuracy.
Regardless of Feature Size can avoid the geometric accuracy to be looser due to dimensional deviation, thereby ensuring the consistency of key geometric functions of controlled features.
- Ensuring Even Tolerancing Distribution
When it is required that multiple features must distribute on their ideal positions evenly in unity, Regardless of Feature Size can ensure that all features would be controlled under the same strictly geometric tolerance.
None of the feature would be special and get larger tolerance zone because of its dimensional deviation.
For example, for a set of mounting holes used for installing a circuit board, their relative positions (specified with positional tolerancing) are critical for stress distribution on the circuit board.
Using RFS ensures that the positional accuracy of each hole is consistent, preventing situations where some holes could be more misaligned simply because they were drilled slightly larger, which ensures even stress distribution across the circuit board.
- Enhancing Measuring Efficiency
When Regardless of Feature Size is applied, instead measuring the actual size of the feature before, it only needs to directly measure the geometric tolerancing value during inspection.
It simplifies measuring procedure and calculating step, thus enhancing measuring efficiency.
3. RFS VS MMC and LMC
In Geometric Dimensioning and Tolerancing, Regardless of Feature Size(RFS), Maximum Material Condition(MMC), and Least Material Condition(LMC) are three different material modifying conditions.
They are mostly different on indication and bonus tolerance.
Regardless of Feature Size is the default condition where geometric tolerances are constant and independent from actual size of the controlled feature. There is no specific symbol for Regardless of Feature Size.
If there is no modifying symbol indicated within feature control frame of the feature, it is default that all geometric tolerances are under Regardless of Feature Size.
Most importantly, Regardless of Feature Size does not allow any bonus tolerance for geometric tolerances. The zone of geometric tolerance is constant regardless of the deviation of actual size from the basic dimension.
Maximum Material Condition refers to the condition where the maximum material amount is contained by the specific feature within its acceptable dimensional tolerance.
In other word, MMC means the smallest size of an internal feature like a hole and the largest size of an external feature like a pin.
Unlike Regardless of Feature Size, Maximum Material Condition should be indicated within a feature control frame as symbol M to make effects.
MMC can ensure that two parts would never interfere even at their worst material condition.
What’s more, compared with Regardless of Feature Size, MMC allows bonus tolerance for geometric tolerances.
MMC defines that the acceptable geometric tolerance zone would be larger when the actual dimension of the feature deviates from its MMC towards LMC. The value of bonus tolerance is similar to that of the dimensional deviation.
Least Material Condition refers to the condition where the minimum material amount is contained by the specific feature within its acceptable dimensional tolerance.
In other word, LMC means the smallest size of an external feature like a pin and the largest size of an internal feature like a hole.
Similar to MMC, Least Material Condition should also be indicated within a feature control frame to come into play. Its symbol is L.
In addition, LMC is commonly applied to the features that have tight requirements on control of the minimum material thickness, especially near edges.
LMC would add bonus tolerance to the initial geometric tolerance when the actual size of the feature deviates from its LMC towards MMC.
4. Conclusion
Regardless of Feature Size is one of the critical modifying conditions in GD&T. It keeps all geometric tolerances irrelevant to the actual size of features, thus providing precise geometric control regardless of a feature’s size.
This article has explained Regardless of Feature Size comprehensively. If you have any other question about it, contact with us directly.
Lucas is a technical writer at ECOREPRAP. He has eight years of CNC programming and operating experience, including five-axis programming. He also spent three years in CNC engineering, quoting, design, and project management. Lucas holds an associate degree in mold design and has self-taught knowledge in materials science. He’s a lifelong learner who loves sharing his expertise.