The radial size is defined as the diameter or mounting position for most parts. If the mounting position is not radially the part is either round or one of two special forms. Rectangular parts like the M-1x1 Structural Panel don't have a radial size or its a size to the next bigger diameter like the Probodobodyne QBE.
There are three radial sizes existing but because of different definition the name vary.
|Name||Meter scale||Actual size||Example|
|Small||1 m||1.25 m||LV-T30 Liquid Fuel Engine|
|Large||2 m||2.5 m||Rockomax "Mainsail" Liquid Engine|
|Radial mounted||—||—||Rockomax 24-77|