The former Wakefield Trinity junior’s performances caught the eye of head coach Jon Sharp and the Featherstone boss has been quick to secure his services.
Hardcastle said: “I am really pleased to have been made an offer and I did not need to hesitate before signing a contract here.
“To play for your hometown club is a big honour and I am really excited about the weeks and months ahead.
“Jon has put together a formidable squad, so I am under no illusions, I will have to fight for my spot and take my chances if and when they come.
“I just want to keep giving my best and keep pushing for a place in the team. Pre-season training has been very tough, making the transition from amateur to professional rugby, but I feel I am progressing well.
“What is pleasing is to see the link between Featherstone Lions and Featherstone Rovers beginning to form, as we have Dave Kitchen and Aaron Lyons also on trial here.”
Sharp has praised Hardcastle’s desire to impress and is hopeful of a bright future for his latest recruit.
He said: “Josh impressed us right from the start, his attitude and approach has been fantastic.
“We offered him the chance to join us for training one night per week and he has turned up for all four sessions, every week, without fail, ever since.
“He has gone the extra mile and his performances on the field have forced us to move quickly in terms of nailing him down as a member of our squad.
“Josh is another great addition for us and I am excited to see how we he develops as the new season progresses.
“I would like to thank Featherstone Lions for their cooperation and support in helping us get the deal done with Josh.
“It is great to see something of a partnership forging between the two clubs.”
Castleford Tigers have released 19-year-old forward Brandon Westerman.
The former Castleford Panthers second-rower, who joined Tigers in 2014, played in the Boxing Day win over Hull and was last Friday awarded squad number 31, but has not made a Super League appearance.
Former Wakefield Trinity back Craig Hall has been named captain of new Kingstone Press League One club Toronto Wolfpack.