A 90 mm swab with a 4 mm tip — a middle size for connector pins and small optical mounts.

Construction

The 4 mm head is large enough to carry a useful solvent dose, small enough for a pin or a thread. It is the size most often specified when a 3.2 mm tip needs two passes and an 8 mm tip will not fit.

Where it is used

  • Connector pins and sockets
  • Small optical mounts
  • Threaded holes before assembly

Handling notes

Change the swab between pin rows. Carrying one head across a connector simply moves flux residue from pin to pin.