Lock Griffiths, is a former Wales Under 18 and Under 21 player who has played for the Dragons and will provide cover in the second row, while prop Davies a former pupil at Hallcross School, came through the system at Doncaster and has played for Wales Under 18 level.
Speaking of the signings Cardiff Blues Director of Rugby, David Young said,
"With the Rugby World Cup season fast approaching many teams will have their squads stretched and Cardiff Blues are no different."
"We are glad to be able to strengthen our squad and bring Welsh talent back to Wales."
"I'm sure both Bryn and Tom will provide extra quality in depth in the front and second rows."
Having returned from their summer break the players will be put through their paces by the Blues conditioning team and there will be an opportunity for supporters to come to watch the players train.
One of the biggest events in the Welsh calendar is the Royal Welsh Show, and the Blues will be travelling to the very north of the region to take part in this years show as they take part in an open coaching session on Wednesday 21 July, between 11.30am and 2.30pm.
The Blues are inviting all their supporters to come down to watch the session and get a glimpse of the type of pre season training the players do over the summer months as well as seeing the unveiling of the new shirt that the team will be wearing next season.
Having held summer events around the region for several years the Blues have always received a terrific welcome from their supporters and on Wednesday 21 August the Blues will be holding a similar session at the Vale Show in Fonmon Castle. This session is also open to all to come and watch just weeks ahead of the new season kicking off in September.