The 29-year-old South African can also play loose head and has penned a 3 year deal with the Welsh Region.
The 6ft, 18st giant has made over 90 appearances for Super Rugby team the Stormers since making his debut for the side in 2007 and just recently completed 100 appearances for Western Province in the Currie Cup.
On signing Harris, Lyn Jones commented: “Following a particularly difficult period last season in the tighter areas of the game, we’ve been determined to ensure there is no repeat.
“Brok will offer the expertise and experience we need to help our young Gwent props grow into future Welsh international players.”
