Pokémon Go ‘Strength of Steel’ Ultra Unlock event challenges and rewards
From July 25-30, steel-type Pokémon will spawn in high numbers in Pokémon Go via the “Strength of Steel” Ultra Unlock Part 2 event.
This article references relevant content from the polygon.com website. Original article link: [https://www.polygon.com/pokemon-go-guide/24206105/strength-of-steel-ultra-unlock-part-2-togedemaru-collection-challenge]

Pokémon Go’s second Ultra Unlock event for the year, “Strength of Steel,” focuses on steel-type Pokémon and runs from July 25-30.
The event gives additional candy for hitting nice throws or better and increases your chance of getting candy XL if you hit nice throws or better. The chance to get Candy XL in general is also increased if you’re level 31 or higher, and you’ll gain triple stardust from catching Pokémon.
Togedemaru is also available shiny for the first time, but the big draw for this event are the Collection Challenges, which reward you with Mega Energy for steel-type Pokémon.
There are also a ton of Collection Challenges, a free Timed Research, and other sweet perks as part of the “Strength of Steel” Pokémon Go event, which we list below.
Pokémon Go ‘Strength of Steel’ event Timed Research and rewards
Rewards: Pawniard encounter, 1 Magnetic Lure Module, 10,000 XP
Pokémon Go ‘Strength of Steel’ event Collection Challenges
There are a few Collection Challenges to complete that involve you catching and evolving specific Pokémon.
Rewards: 5,000 Stardust, Steelix encounter, 100 Steelix Mega Energy
Rewards: 5,000 Stardust, Aggron encounter, 100 Aggron Mega Energy
Rewards: 5,000 Stardust, Scizor encounter, 100 Scizor Mega Energy
Pokémon Go ‘Strength of Steel’ event Field Research and rewards
Spinning a PokéStop during the event period may yield one of these tasks:
Pokémon Go ‘Strength of Steel’ event boosted spawns
These Pokémon will spawn more frequently during the event period:

Pokémon Go ‘Strength of Steel’ event raid targets
These Pokémon will be in raids during the event: