500A 115 PC Cobalt Drill Bit Set

DRILLCO 500A 115-Piece M42 Cobalt Drill Bit Set — High-Speed Drilling in Hard Materials

The DRILLCO 500A is a 115-piece M42 cobalt HSS drill bit set engineered for heavy-duty drilling in hard, tough materials including stainless steel, titanium, and high-strength alloys. Built to NAS Type J aircraft specifications, this set covers fractional sizes 1/16–1/2 by 64ths, number sizes #1–60, and letter sizes A–Z, making it a comprehensive solution for contractors and trades professionals who need a single set for a wide range of hole sizes. The 135° split-point geometry is self-centering, reducing thrust requirements and minimizing bit walk on curved or hard surfaces. A bronze surface treatment enhances lubricity and extends bit life while reducing chip build-up during demanding drilling operations.

Technical Specifications

Available Sizes

Unlike standard HSS drill sets, the M42 cobalt composition of this set delivers approximately 30% faster drilling speeds than conventional HSS drills, while the NAS Type J aircraft-grade construction ensures the heavy-duty performance required for stainless steel, titanium, and high-strength alloys. The bronze surface treatment further differentiates this set from black oxide alternatives by providing superior lubricity specifically suited to harder metals.

Key Features & Benefits

M42 Cobalt HSS Construction

M42 cobalt high-speed steel offers increased hardness and wear resistance compared to standard HSS, making it well-suited for drilling into harder steels and stainless steel grades. The high red hardness of the cobalt alloy allows the bits to maintain cutting performance even as heat builds up during aggressive drilling operations.

Approximately 30% Faster Drilling Than HSS

Cobalt drills can drill approximately 30% faster than standard HSS drills, directly reducing cycle times on the job. For contractors drilling large volumes of holes in hard materials, this speed advantage translates to measurable productivity gains over the course of a project.

135° Self-Centering Split-Point

The 135° split-point geometry is self-centering, which reduces thrust requirements and minimizes bit walk when starting a hole — particularly valuable on curved or hard surfaces where a conventional point would skate. This design allows drilling to begin immediately without a center punch in many applications.

Bronze Surface Treatment

The bronze surface treatment increases lubricity and bit life while reducing chip build-up during drilling. This treatment is specifically suited for performance on harder metals and stainless steel, where heat and friction management are critical to tool longevity.

NAS Type J Aircraft Specification

These bits are manufactured to NAS Type J aircraft specifications, reflecting heavy-duty construction standards designed for demanding industrial and aerospace-grade drilling applications. This specification gives contractors confidence that the bits are built to consistent, rigorous tolerances.

Jobber Length for Versatile Reach

Jobber length is the most common drill length because it provides extra reach and can be used in most applications. This makes the 500A set a practical all-around choice for contractors who need one set to handle a broad range of drilling tasks across different setups.

Comprehensive 115-Piece Coverage

The set includes fractional sizes 1/16–1/2 by 64ths, number sizes #1–60, and letter sizes A–Z, covering virtually every standard hole size a contractor is likely to encounter. Having this range in a single set eliminates the need to source multiple individual bits or partial sets for different jobs.

Common Applications

Drilling in Stainless Steel

The M42 cobalt composition and bronze surface treatment make this set specifically suited for drilling stainless steel, where heat buildup and work hardening can quickly degrade standard HSS bits.

Drilling in Titanium

Titanium's toughness and tendency to gall make it a challenging material for standard drills; the cobalt HSS substrate and 135° split-point geometry of this set are designed to handle such demanding materials.

High-Strength Alloy Drilling

For high-strength alloys encountered in structural, aerospace, or heavy fabrication work, the NAS Type J specification and M42 cobalt construction provide the durability and cutting performance required.

Heavy-Duty Industrial Drilling

The heavy-duty construction and aircraft-grade specification make this set appropriate for production and industrial drilling environments where bit consistency and longevity are critical.

Compatible Materials

• Stainless steel
• Titanium
• High-strength alloys
• Hard, tough metals

Product Documents

• Safety Data Sheet (SDS)
• Drillco Product Linecard

Safety Data Summary

Hazard Information

• During normal operation and usage, the product does not present inhalation, ingestion, or other chemical hazards.
• Grinding, cutting, machining, burning, or welding may release dusts, fumes, or vapors that present health hazards if exposure limits are exceeded.
• Excessive inhalation of metallic fumes and dusts may cause irritation of eyes, nose, and throat.
• High concentrations of fumes and dusts of iron oxide, manganese, copper, zinc, and lead may result in metal fume fever (metallic taste, throat irritation, chills, fever — symptoms may persist 12–48 hours).
• Cobalt is listed as a Group 2B carcinogen by IARC (possibly carcinogenic to humans). Chromium and Nickel are listed by NTP and OSHA as carcinogens.
• Chronic exposure to cobalt dusts, fumes, or mists may cause permanent respiratory diseases including occupational asthma, interstitial pneumonitis and fibrosis (hard-metal disease), and emphysema.
• Skin sensitization to cobalt is noted in a small percentage of cases.
• Fine metal particles produced when ground or sawed can burn; high concentrations in air may present an explosion hazard.
• NFPA Hazard Rating: Health 1; Flammability 0; Reactivity 0
• California Proposition 65 Warning: This product can expose you to chemicals including Cobalt, which is known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov

Personal Protective Equipment

• Wear safety glasses or goggles with side shields; do not wear contact lenses when handling these materials.
• Cloth or leather gloves are recommended when contact with dust or mist is likely.
• Use an appropriate NIOSH-approved respirator if airborne dust concentration exceeds the applicable PEL or TLV.
• Hearing protection may be required.
• Always use machine guards and wear protective clothing to prevent injury in the event of tool breakage.
• Employer should provide an eye wash station within the immediate work area for emergency use.

Safe Handling

• Use only with local exhaust ventilation adequate to limit personal exposure to airborne dust below PEL or TLV levels.
• Clean up using methods that avoid dust generation: vacuum with appropriate filters, wet dust mop, or wet clean-up.
• Store in a dry place; store in a manner that prevents accidental environmental contamination from traces of industrial lubricants or wetting oils.
• Wash hands thoroughly after handling and before eating or smoking; wash exposed skin at end of work shift.
• Do not shake clothing, rags, or other items to remove dust — remove dust by washing or vacuuming with appropriate filters.
• Soiled clothing should be laundered separately.
• Incompatible with strong acids and strong oxidizers.
• For powder fires, smother with dry sand, dry dolomite, ABC-type fire extinguisher, or flood with water.
• Do not release runoff from fire control methods to swales or waterways.

Frequently Asked Questions

Q: What materials is this drill bit set designed to drill?
A: The 500A set is designed for drilling holes in hard, tough materials such as stainless steel, titanium, and high-strength alloys. It is specifically built for heavy-duty drilling applications where standard HSS bits would underperform.

Q: What sizes are included in the 115-piece set?
A: The set includes fractional sizes 1/16–1/2 by 64ths, number sizes #1–60, and letter sizes A–Z — 115 pieces total under item number 500A0115.

Q: How much faster do these cobalt bits drill compared to standard HSS bits?
A: Cobalt drills can drill approximately 30% faster than standard HSS drills, according to DRILLCO's product data.

Q: What is the point angle, and why does it matter?
A: These bits feature a 135° split-point. This geometry is self-centering, which reduces thrust requirements and minimizes bit walk — particularly useful when starting holes on curved or hard surfaces without a center punch.

Q: What specification standard are these bits built to?
A: These bits are manufactured to NAS Type J (Aircraft) specifications, reflecting heavy-duty construction standards for demanding industrial drilling applications.

Q: Are there any critical operating tips for getting the best performance from these bits?
A: Yes — speed, feed, and lubrication are all critical to cutting tool performance. Proper attention to all three factors will maximize bit life and cutting efficiency, especially when drilling hard materials like stainless steel.