Drill America Z Cobalt Heavy Duty Drill Bit Pack of 6 - High Heat

In this review the Drill America Z Cobalt Heavy Duty Drill Bit (Pack of 6) is assessed as a workhorse set for machinists and fabricators who need reliable performance on tough alloys. The bottom line: these jobber length bits are built from heat resistant cobalt to maintain higher red hardness so they run up to 30 percent faster than standard HSS in demanding metals, making them a practical choice when drilling PH stainless steel, inconel, or titanium. For someone who cuts exotic or high tensile materials regularly, the set delivers consistent life and cutting speed without unnecessary fragility.

Key Features

• Heat resistant cobalt: Maintains cutting hardness at elevated temperatures so the bit stays sharp longer under heavy loads.
• National Aerospace standard 907 manufacturing: Indicates consistent geometry and material quality for repeatable, accurate holes.
• Jobber length: Offers a useful balance of reach and rigidity for general shop and field work without excessive flex.
• Higher red hardness: Allows drilling speeds up to 30 percent greater than HSS, reducing cycle time on tough alloys.
• Effective on high tensile materials: Specifically suitable for PH stainless steel, inconel, and titanium where standard bits struggle.

Who It's For

The Drill America Z Cobalt pack is aimed at professional machinists, aerospace technicians, and serious hobbyists who frequently drill high strength or heat-resistant alloys. It suits shops that need a durable, repeatable jobber length bit that keeps cutting performance when temperatures climb and material hardness is high.

It is less appropriate for casual home users who seldom work with exotic metals; in those cases a standard HSS set provides better economy. Users needing extra-long reach or specialized coatings for specific materials should look elsewhere.

Pros & Cons

Pros

• Excellent heat resistance so bits maintain hardness and performance under sustained cutting.
• Manufactured to a National Aerospace standard, supporting reliable geometry and consistency.
• Designed for tough materials like PH stainless steel, inconel, and titanium where HSS fails prematurely.

Cons

• Higher cost than standard HSS bits, which may be unnecessary for light or occasional use.

Specifications

Brand	Drill America
Series	D/ACO (Z Cobalt)
Pack Size	6 bits
Length	Jobber length
Material	Heat resistant cobalt
Standard	Manufactured to National Aerospace standard 907

Our Verdict

The Drill America Z Cobalt Heavy Duty Drill Bit pack is a solid investment for professionals who regularly drill high tensile or heat-resistant alloys. Its cobalt construction and aerospace manufacturing standard provide reliable cut life and faster drilling speeds compared with HSS, delivering good value where material and time savings matter most.

Frequently Asked Questions

Can these bits drill stainless and titanium?
Yes; they are specifically effective on PH stainless steel, inconel, and titanium due to their cobalt composition and higher red hardness.

Are these jobber length bits suitable for bench drills?
Yes; jobber length gives a balance of reach and rigidity appropriate for most bench and drill press work.

Do they replace coated HSS bits for general use?
They excel on tough alloys but may be more costly than needed for light general purpose drilling in soft metals or wood.