RGC and Merthyr will be bidding to become only the 15th club to reach the WRU National Cup final when they go head-to-head in the semi-finals.
The two Principality Premiership Tier 1 clubs were drawn together to ensure there will be a new club in the final, and the contest will take place on Saturday, March 25.
Pontypridd will meet Cross Keys in a repeat of the 2012 and 2014 finals, with the venues for both fixtures still to be determined.
RGC have already beaten the Ironmen twice in the Premiership this season - 23-19 at The Wern and 25-24 at Parc Eirias - and if Mark Jones' side can complete a hat-trick of wins it would carry them to the Principality Stadium five years after they entered Division 1 East.
A last minute try from Huw Worthington enabled them to knock-out the cup holders, Llandovery, 45-36 in an epic quarter-final in Colwyn Bay and they are still on course for a league and cup double.
Mark Jones’ side will be looking for revenge this weekend when they host second placed Bedwas at Parc Eirias, who they lost 27-17 to earlier this season on their travels.
They will be without the services of captain Maredydd Francis for foreseeable future, as the forward suffered a dislocated shoulder against Llandovery and is due to have a scan this week.
TV company S4C also confirmed that the Gogs’ game with Ebbw Vale on April 8 has been chosen for live coverage.