John Gill Commentary Exodus 26:37

"And thou shalt make for the screen five pillars of acacia, and overlay them with gold: their hooks shall be of gold: and thou shalt cast five sockets of brass for them." — Exodus 26:37 (ASV)

And you shall make for the hanging five pillars of
shittim wood
One at each corner of the entrance into the tabernacle, and the other three at a proper distance from each other, so as to make four ways for the priests to enter in at; as there might very well be, since there was a breadth of ten cubits, or five yards or more.

and overlay them with gold ;
with plates of gold, for a gild would soon wear off by continual use in passing and repassing. This is to be understood not of the whole pillars, but of the chapiters, heads, tops, or knobs of them, and of their fillets or girdles; in some parts of them the wood appearing, as is plain from (Exodus 36:38) (38:28) :

and their hooks shall be of gold ;
on which the hanging, covering, or veil was hung.

and you shall cast five sockets of brass for them ;
for the pillars to stand upon them, and were of a meaner metal than those on which the pillars for the veil before mentioned; that being the entrance into the holy of holies, where the divine Majesty dwelt, this into the holy place where the priests did their service.