There are 8 drills in the game. Each one made of a different ore and progressively more expensive as their quality increases. New drills can be purchased at the junk shop.

Effect - Code

Amazonite Drill (120 ft./s) - Buy for $500,000
Diamond Drill (95 ft./s) - Buy for $100,000
Emerald Drill (50 ft./s) - Buy for $5,000
Goldium Drill (40 ft./s) - Buy for $2,000
Ruby Drill (70 ft./s) - Buy for $20,000
Silvide Drill (28 ft./s) - Buy for $750
Stock Drill (<28 ft./s) - Start a new game