500A 29 PC Cobalt Drill Bit Set

DRILLCO 500A 29-Piece Cobalt Drill Bit Set — High-Speed M42 Cobalt for Hard Materials

The DRILLCO 500A is a 29-piece jobber-length cobalt drill bit set manufactured from premium grade M42 cobalt high-speed steel, 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 sizes from 1/16" to 1/2" by 64ths, making it a comprehensive solution for contractors and trades professionals who regularly work with demanding materials. The 135° split-point geometry is self-centering, reducing thrust requirements and minimizing bit walk on curved or hard surfaces. A bronze surface treatment provides high lubricity, reducing chip build-up and extending bit life in harder metals and stainless steel applications.

Technical Specifications

Compared to standard HSS drill bits, the M42 cobalt construction of the 500A set delivers approximately 30% greater drilling speeds due to its high red hardness — meaning the material retains its hardness at elevated cutting temperatures. The NAS Type J aircraft specification and bronze surface treatment distinguish this set from general-purpose HSS options, making it the appropriate choice when working with stainless steel, titanium, and other high-strength alloys that would rapidly degrade standard HSS tooling.

Key Features & Benefits

Premium Grade M42 Cobalt HSS Construction

M42 cobalt high-speed steel offers superior red hardness compared to standard HSS, allowing the drill to maintain its cutting edge at the elevated temperatures generated when drilling hard and tough materials. This translates directly to longer tool life and fewer bit changes on the job site. Cobalt drills can drill approximately 30% faster than HSS drills in demanding applications.

135° Self-Centering Split-Point

The 135° split-point geometry is self-centering, which reduces the need for a center punch and minimizes bit walk on hard or curved surfaces. Reduced thrust requirements mean less operator fatigue and lower risk of bit breakage when drilling into high-strength materials. This point design is particularly effective for hand-drilling applications on harder materials.

Bronze Surface Treatment for High Lubricity

The bronze surface treatment increases lubricity and bit life while reducing chip build-up during cutting. This is especially beneficial when drilling stainless steel and other hard metals where heat and friction are primary causes of premature tool failure. The treatment is specifically suited for performance on harder metals and stainless steel.

NAS Type J Aircraft Specification

Built to NAS Type J aircraft specifications, these bits meet the heavy-duty construction standards required for aerospace-grade drilling applications. This specification provides contractors with confidence that the tooling is manufactured to a recognized, rigorous standard for use in demanding environments.

Jobber Length for Versatile Reach

Jobber length is the most common drill length because it provides extra reach while remaining suitable for the majority of drilling applications. This makes the 500A set a practical all-around solution for contractors who need a single set capable of handling most job site scenarios.

Comprehensive 29-Piece Size Range

The set covers 1/16" to 1/2" by 64ths, providing a complete progression of sizes for a wide variety of hole diameters in a single kit. Having every size from 1/16" to 1/2" on hand eliminates the need to source individual bits for common drilling tasks.

Common Applications

Drilling in Stainless Steel

The M42 cobalt construction and bronze surface treatment are specifically suited for drilling stainless steel, where heat generation and work hardening rapidly degrade standard HSS bits.

Drilling in Titanium

Titanium's combination of high strength and low thermal conductivity makes it one of the most demanding materials to drill; the high red hardness of M42 cobalt maintains cutting performance under these conditions.

High-Strength Alloy Drilling

For high-strength steel alloys and other tough materials encountered in structural, industrial, and fabrication work, the cobalt substrate and NAS Type J specification ensure reliable performance where general-purpose HSS tooling would fail prematurely.

Heavy-Duty Drilling Operations

The heavy-duty construction and aircraft-grade specification make this set appropriate for sustained, high-demand drilling tasks where tool longevity and consistent performance are critical.

Compatible Materials

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

Product Documents

• Safety Data Sheet (SDS)
• DRILLCO Product Linecard

Safety Data Summary

Hazard Information

• During normal operation, cobalt cutting tools do 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).
• Chronic exposure to cobalt dusts, fumes, and mists may cause permanent respiratory diseases including occupational asthma, interstitial pneumonitis and fibrosis (hard-metal disease), and emphysema.
• Chromium and nickel are listed as carcinogens by NTP and OSHA; cobalt is listed as Group 2B by IARC (possibly carcinogenic to humans).
• Skin contact with dust may cause irritation or allergic skin rash due to cobalt sensitization.
• Eye contact with dust may cause irritation.
• 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 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

• Perform grinding, cutting, and machining operations in well-ventilated areas; use local exhaust ventilation adequate to limit airborne dust below PEL or TLV.
• Clean up using methods that avoid dust generation: vacuum with appropriate filters, wet dust mop, or wet clean-up.
• 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.
• Store in a dry place in a manner that prevents accidental environmental contamination from traces of industrial lubricants or wetting oils.
• 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. Use NIOSH-approved respirator for toxic dusts and fumes; use self-contained breathing apparatus for large fires.
• If inhalation symptoms develop (coughing, wheezing, shortness of breath), remove from exposure and seek medical attention.
• If skin irritation or rash occurs, wash thoroughly with soap and water; seek medical attention if it persists.
• If eye irritation occurs, flush with copious amounts of water; seek medical attention if it persists.

Frequently Asked Questions

Q: Why choose cobalt (M42) drill bits over standard HSS bits for stainless steel?
A: M42 cobalt HSS has higher red hardness than standard HSS, meaning it retains its cutting edge at the elevated temperatures generated when drilling stainless steel and other hard alloys. Cobalt drills can drill approximately 30% faster than HSS drills in these demanding materials, and the bronze surface treatment further reduces heat and chip build-up.

Q: What does the 135° split-point offer compared to a conventional 118° point?
A: The 135° split-point is self-centering, which reduces bit walk on hard or curved surfaces and lowers thrust requirements. This makes it particularly well-suited for hand-drilling on harder materials where a conventional point would tend to skate before engaging.

Q: What does NAS Type J specification mean for this drill set?
A: NAS Type J is an aircraft-grade specification for heavy-duty drill construction. Meeting this standard indicates the bits are built to rigorous dimensional and material requirements suitable for demanding aerospace and industrial drilling applications.

Q: What size range does the 500A29 set cover?
A: The set includes 29 pieces covering 1/16" to 1/2" by 64ths, providing a complete progression of jobber-length cobalt drill sizes for a wide range of hole diameters.

Q: What role do speed, feed, and lubrication play when using these bits?
A: According to DRILLCO, speed, feed, and lube are all critical to cutting tool performance. Using the correct combination for the material being drilled will maximize bit life and cutting efficiency; improper speed or insufficient lubrication are primary causes of premature tool wear in hard materials.