Heb. hashukum, plur., joinings (Exodus 27:17; 38:17,28), the rods by which the tops of the columns around the tabernacle court were joined together, and from which the curtains were suspended (Exodus 27:10,11; 36:38).
In Jeremiah 52:21 the rendering of a different word,
Hut , meaning a "thread," and designating a measuring-line of 12 cubits in length for the circumference of the copper pillars of Solomon's temple.
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Fillets'". "Easton's Bible Dictionary".