The overall length of a two-piece capsule after its cap and body are joined in the final locked position.
Also called: closed length; closed joined length; final locked length; Locked length.
Cap, body and joined capsule lengths
A two-piece capsule has separate cap and body dimensions as well as an overall joined length. The cap overlaps the body, so adding the two part lengths does not give the final overall length.
Pre-lock is the supplied joining state intended to keep the empty halves together before filling. Final locked length refers to the closed state after filling. Read the dimension label and state, not just the number beside the size designation.
Length labels refer to different features or states
Label
What it describes
Cap length / body length
An individual shell part.
Pre-lock length
The overall empty capsule in its preliminary joined state.
Is one published locked length valid for every shell of that size?
Use the relevant supplier’s specification for the shell and variant being discussed. Published charts can use different nominal values; a historical table or another manufacturer’s figure is not a substitute for the applicable drawing and tolerances.
A length result describes geometry. It does not establish the force needed to close the capsule, its actual net fill mass or the complete condition of the shell. Those are separate attributes. For a machine discussion, identify the manufacturer, size variant, drawing revision and whether the reported dimension is pre-lock or final locked.