This MP3 1/4" x 4-1/4" carbide tipped drill bit provides maximum penetration, maximum potency, maximum persistency. Built to last longer, Lockmasters' carbide hardplate drill bit has proven itself as a leader in the safe and vault industry. Students using the MP3 were amazed at the effectiveness of this bit when drilling through GSA red label hardplate. Features: Tip has special negative rake and can be resharpened. Works exceptionally well on carbide matrix hardplate. High tech bonding allows bit to withstand drilling temperatures up 1900 degrees fahrenheit. Lasts longer than most regular carbide tipped bits. Chrome vandium steel shank provides extra hardness and enormous strength.