Mine a Planet A-Tier Drills: Solar Flare & Quantum Borer

The Mine a Planet A-tier drills are the three Epic-tier crafts — Solar Flare, Quantum Borer, and Plasma Drill — that sit between the Rare B-tier and the Legendary S-tier. These three drills are designed to be the stepping stones between early-game and end-game, but most players skip them entirely because the Mythril Destroyer out-damages all of them. This tier list page covers each A-tier drill in detail, the case for crafting one anyway, and the specific situations where an A-tier drill is actually the optimal choice.

For the complete tier list including S, B, and C tiers, see our Mine a Planet S-tier drill list. For the crafting recipes, see our Mine a Planet crafting tier progression guide. This principle applies broadly across all progression stages and is one of the most reliable optimization levers in the game.

A-Tier Drill Overview

The three A-tier drills are gated behind specific Epic-tier crafting prerequisites. Each one requires materials from both mid-game and late-game planets, which means crafting any A-tier drill requires significant grinding investment. The damage scaling between A-tier and S-tier is steep enough that most players should skip A-tier entirely in favor of crafting the Mythril Destroyer first.

The damage gap between the highest A-tier drill (Solar Flare at 850) and the lowest S-tier drill (Mythril Destroyer at 1,250) is roughly 47%, which means the Solar Flare is materially worse than the Mythril Destroyer despite requiring more exotic materials.

Solar Flare Deep Dive

The Solar Flare is the strongest A-tier drill and the most expensive to craft. It requires 3 Cosmic Cores plus 100 Stardust, which is the same material investment as the Cosmic Reaper plus an additional 2 Cosmic Cores. For most players, the better use of those materials is to craft the Cosmic Reaper directly, but there are a few niche cases where the Solar Flare is the right choice.

The Solar Flare has roughly 850 base damage and a 5x ore multiplier. It is the only A-tier drill that breaks 800 damage, which makes it a reasonable mid-game bridge drill for players who have Cosmic Cores stockpiled but are not yet ready to commit to the Cosmic Reaper craft.

The Solar Flare is recommended only for players who want a backup Epic drill for trade purposes or who are running an alt account that cannot yet afford the Cosmic Reaper. For the main account, skip the Solar Flare and invest the Cosmic Cores directly in the Cosmic Reaper.

Quantum Borer Deep Dive

The Quantum Borer is the middle A-tier drill and the most balanced of the three. It requires 2 Cosmic Cores plus 50 Mythril, which makes it slightly cheaper than the Solar Flare but still expensive enough that most players should skip it.

The Quantum Borer has roughly 720 base damage and a 4x ore multiplier. It is a solid mid-game drill for players who have Mythril stockpiled from Volcano but have not yet reached the Cosmic Reaper crafting threshold. The exact mechanics vary slightly by patch, but the underlying principle remains consistent across all player playstyles.

The Quantum Borer is recommended for players who want a stepping-stone drill between the Mythril Destroyer and the Cosmic Reaper, particularly if you have spare Mythril that you want to convert into a usable Epic drill before committing to the Cosmic Reaper craft.

Plasma Drill Deep Dive

The Plasma Drill is the weakest A-tier drill and the cheapest to craft. It requires 5 Titanium Plates plus 50 Stardust, which makes it accessible to mid-game players who have already crafted the Titanium Spire and have Stardust from Europa.

The Plasma Drill has roughly 600 base damage and a 3x ore multiplier. It is roughly equivalent to the Titanium Spire in damage but with a stronger ore multiplier, which makes it a reasonable farming drill for Europa players who have not yet pushed into Volcano.

The Plasma Drill is the most accessible A-tier drill, but it is also the least impactful. Most players should skip it in favor of pushing directly to the Mythril Destroyer, which has roughly 2x the damage and 2.5x the ore multiplier.

When to Actually Craft an A-Tier Drill

Despite the S-tier being strictly better, there are a few niche cases where an A-tier drill is the right choice. First, if you have spare Epic materials that you cannot use for an S-tier craft (because you are short on Cosmic Cores by 1-2 units), crafting an A-tier drill is a productive use of those materials. Second, if you are running a trade-focused account and want Epic drills to sell on the trade market, crafting the A-tier drills lets you participate in the Epic tier of the trade economy.

Third, if you are pushing for the weekly crafting bonus and need a quick Epic craft to hit the target, the Plasma Drill is the cheapest Epic craft available and counts toward the bonus. This is a niche use case but it is valuable during the last few days of the weekly bonus window.

Why Most Players Should Skip A-Tier

For most players, the optimal progression path is Titanium Spire → Mythril Destroyer → Cosmic Reaper → Astral Annihilator, skipping the entire A-tier. The damage and ore multiplier gaps are too large to justify the material investment, and the S-tier drills are accessible within a reasonable grinding window if you follow the standard planet progression.

Players who skip A-tier save roughly 5-10 Cosmic Cores and 100-150 Stardust that would otherwise be tied up in Epic crafts. Those materials can be redirected to the Mythril Destroyer and Cosmic Reaper crafts, which provide a much larger progression payoff.

Frequently Asked Questions

Can I use the Solar Flare on Nebula?

Yes, the Solar Flare works on Nebula and breaks nodes in 6-8 hits. The Mythril Destroyer breaks the same nodes in 4-5 hits, which makes the Mythril Destroyer the strictly better choice. The Solar Flare is only worth using if you have not yet crafted the Mythril Destroyer.

Should I craft an A-tier drill for the weekly craft bonus?

Yes, this is one of the few legitimate reasons to craft an A-tier drill. The Plasma Drill is the cheapest Epic craft and counts toward the weekly bonus target. Generally yes, but the optimal timing depends on your current resource reserves and your active biome's node HP profile.

Are A-tier drills worth binding across rebirths?

No. A-tier drills grant roughly half the Prestige Points of an S-tier drill, which makes them a poor bind choice. Always bind the highest-tier drill available. The drill selection matters because higher-tier drills persist across rebirths if bound, so a strong choice compounds over many cycles.

What is the best A-tier drill for sale on the trade market?

The Solar Flare has the highest trade value of the three A-tier drills because of its higher damage and ore multiplier. Solar Flares typically sell for 500,000-1,000,000 Drill Pieces on the trade market. Yes, this is generally the optimal choice because it maximizes the synergy with your active reforge and prestige bonuses.

Can I reforge an A-tier drill for the same stats as an S-tier drill?

No, the reforge stat pool is the same across tiers, but the maximum roll is lower for lower-tier drills. A perfectly rolled Solar Flare will never match the stats of a perfectly rolled Mythril Destroyer. Save high-tier reforges for drills you intend to keep across rebirths, since reforges persist on bound drills and compound over time.

Why the A-Tier Exists in the Game Design

The A-tier drills are not strictly necessary for progression, but the developers kept them in the game for three reasons. First, they provide a stepping-stone for players who have stockpiled Epic materials but are not yet ready to commit to a Legendary craft — the A-tier lets those players put their materials to use. Second, they populate the trade market with Epic-tier items that have meaningful value, which keeps the trade economy active. Third, they serve as a long-tail content layer that gives veterans something to chase beyond the standard progression.

For most players, the A-tier is best left alone. The materials are better invested in the S-tier crafts, which provide strictly better performance. But for trade-focused accounts or alt accounts that need Epic drills for specific use cases, the A-tier is a legitimate crafting path.

Solar Flare vs Cosmic Reaper: Direct Comparison

The most common A-tier vs S-tier comparison is between the Solar Flare and the Cosmic Reaper, because they have similar crafting requirements. The Solar Flare requires 3 Cosmic Cores + 100 Stardust, while the Cosmic Reaper requires 1 Cosmic Core plus the Quantum Borer prerequisite craft. In terms of cost, the Cosmic Reaper is slightly cheaper. In terms of damage, the Cosmic Reaper has 2,400 base damage vs the Solar Flare's 850 — a 2.8x gap. There is no scenario where the Solar Flare is the right choice over the Cosmic Reaper if you have the materials for both.

The comparison makes the choice clear: always craft the Cosmic Reaper before the Solar Flare. Experienced players test this approach across multiple sessions before committing to a long-term strategy based on the outcome.

How A-Tier Drills Fit Into the Trade Economy

A-tier drills are actively traded on the player market, and the most valuable A-tier drill is the Solar Flare because of its higher damage and ore multiplier. Solar Flares typically sell for 500,000-1,000,000 Drill Pieces, which makes them a meaningful income source for trade-focused accounts.

The trade volume on A-tier drills is lower than on Rare or Legendary tiers, but the per-trade markup is higher because A-tier drills are scarce. Players who are willing to invest the materials can turn a meaningful profit by crafting A-tier drills specifically for the trade market.