Halifax 15:00 Rovers
Bulldogs 15:00 Eagles
Raiders 15:00 Thunder
Whitehaven 15:00 Knights
Hunslet 15:00 Skolars
Streamed live on the BBC Sport website, the tie of the round will take place on Recs' new 4G pitch.
The two NCL Premier Division heavyweights traded a win each last season, Pilks winning 33-28 at home and losing 32-20 on the road at Siddal.
Recs will be playing on their new 4G pitch for the first time, but Siddal already have experience on the surface, as captain Shaun Garrod explains: "We won the NCL Grand Final on the 4G pitch at Widnes last year and we loved the experience.
"It's completely different. It's a fast-flowing surface and that'll suit our game.
"Pilks beat us once last year and we beat them once, and they were both really close games.
"It's definitely the tie of the round and all the lads are buzzing to be involved.
He added: "We've got good memories of the Challenge Cup from last year, beating Newcastle Thunder (30-4) in round three, so hopefully we can get through to the third round and do something like that again."
Siddal won the NCL Grand Final in 2016
Pilkington Recs beat London Skolars 13-0 in the third round last season
Saturday's early kick off sees two sides who swapped places in 2016 going head-to-head.
Hull-based Myton, who beat The Royal Navy 38-34 in Portsmouth in round one, were promoted to the NCL Premier Division last season after winning promotion from Division 1, while Acorn eased past the Royal Air Force 30-12 in Lincolnshire two weeks ago, but were relegated from the NCL's top tier in 2016.
The two sides last faced off in 2014, when Myton won 17-16 in an NCL Division 1 match.
Two sides who will be going head-to-head for the first time ever this weekend, as London's Wests Warriors travel to West Yorkshire.
The Lions, who qualified for the NCL Division 1 play offs last year, come into the game as slight favourites, but will not underestimate their visitors on Saturday, who won the Harry Jepson Trophy and London Men's League last season and haven't lost in any competition or friendly game since April 2016.
Wests Warriors are playing in the Challenge Cup for the first time
Featherstone Lions made it to the fourth round last year
Haydock, who stole the headlines with a 17-4 giant-killing at Wath Brow Hornets in round one, face another NCL side in Thornhill this weekend.
The North West Men's League champions will have to be on their game again to upset their visitors, who play in the NCL's third tier and won the BARLA National Cup last season.
And Thornhill will be confident after they shocked Lock Lane, who were relegated from the NCL's Premier Division last season, 32-18, two weeks ago to seal their place in the second round.
Another all-NCL Premier Division clash as Mayfield, 2016 Challenge Trophy winners, travel to Whitehaven.
Kells, who edged out West Bowling 12-0 away from home in round one, will be looking to make the most of home advantage, but will know they are in for a tough test having lost to Mayfield, who beat The University of Hull 22-12 in East Yorkshire in the last round, twice last season.
One of four all-NCL Premier Division clashes sees Thatto Heath, promoted from Division 1 last season, take on West Hull, who finished second in the top tier in 2016.
West Hull do come into the game as favourites, but Thatto, from St Helens, are on a roll having won their last eight games in all competitions.
Thatto overcame Skirlaugh 30-10 on home turf in round one, while West Hull came out on top 24-10 in a hard-fought local derby against Hull Dockers
After an enthralling 16-12 win at Leigh Miners Rangers live on the BBC Sport website, Wigan St Pats were rewarded with their first home Challenge Cup tie since 2014.
They will be welcoming fellow NCL Premier Division outfit Egremont this weekend and will be favourites for the tie, having finished eight points ahead of their visitors last season, who beat the British Army 24-14 in round one.
London Chargers, Conference League South champions last year, strolled to a remarkable 116-0 win over a depleted Bridgend Blue Bulls side in round one, but will be set for a tougher test this time around.
Castleford-based Fryston, champions of the winter Pennine League, brushed local rivals Normanton Knights aside in a 33-10 home demolition two weeks ago and will be hoping to become the first Tier 5 side to make it to round three since Widnes West Bank achieved the feat in 2015.