Regardless of feature size means the stated geometric tolerance remains the same as the actual feature size changes within its size limits. In common feature-control-frame usage, it is the default when no MMC or LMC modifier follows the tolerance value.
One geometric tolerance at every actual size
With RFS, a 0.20 mm position tolerance remains 0.20 mm whether a hole is at its smallest permitted size, largest permitted size, or somewhere between. There is no bonus tolerance tied to actual size.
When RFS is a good fit
Use RFS when the geometry itself matters independently of size. A hole may need to stay accurately located at every permissible diameter because it aligns a mechanism, supports a load, or controls a fluid path.
Compare it to MMC and LMC
MMC and LMC deliberately couple size to geometric tolerance. RFS does not. Before interpreting any frame, look for a material-condition modifier after the tolerance value instead of assuming that every position control includes bonus tolerance.
Example: position at RFS
Because no M or L modifier follows 0.20, the hole axis has a 0.20 mm diameter position zone at every allowed hole size.
Common mix-up
RFS is not “no size requirement.” The feature must still meet its stated size limits as well as the geometric tolerance.
Keep learning
Explore the foundations
Foundation 01
Datums
Open guide →Foundation 02
Feature Control Frames
Open guide →Foundation 03
Maximum Material Condition (MMC)
Open guide →Foundation 04
Least Material Condition (LMC)
Open guide →Foundation 05
Basic Dimensions & Tolerance Zones
Open guide →Foundation 06
Regardless of Feature Size (RFS)Current pageFoundation 07
Rule #1 & Features of Size
Open guide →Foundation 08
Virtual Condition & Functional Gaging
Open guide →Foundation 09
Datum Feature Modifiers & Datum Shift
Open guide →Foundation 10