GD&T Regardless of Feature size

What does Regardless of feature size or RFS mean in GD&T ? How is it different from Material condition modifiers?

When there is no material condition modifier used along with the geometric tolerance in the Feature control frame then the positional control of that FOS is said to be Regardless of Feature size.

It means that there will be no change in total positional tolerance of the feature of size (whether hole or shaft) with respect to its size

There will be no Bonus tolerance applied in such a case.

The tolerance zone size remains same irrespective of feature size.

Comparison of RFS, MMC and LMC in Feature control frame

In comparison to RFS , here is the same drawing with a material condition modifier attached along with the geometric tolerance in the feature control frame . The meaning changes, positional tolerance is no longer “regardless of feature size” but depends on the feature size.

For the LMC modifier the bonus tolerance applied.

RFS (regardless of Feature size) rule is also called as Rule #2 in GD&T .

The rule is that when there is no material condition modifier is used along with geometric tolerance the positional tolerance has to be considered regardless of feature size, no need to add bonus tolerance.

Learn more about how to Interpret GD&T callouts from this e-book on GD&T interpretations