200LH 29 PC Drill Set

DRILLCO 200LH 29-Piece Left Hand Drill Set — Counterclockwise Drilling for Broken Bolt Removal

The DRILLCO 200LH 29-piece left hand drill set is a general-purpose High Speed Steel (HSS) drill set engineered for counterclockwise drilling operations. It is designed for use in close-center multiple spindle gear-driven drilling heads where adjacent spindles operate alternately left and right hand, as well as in left hand screw machines. The set is also a practical solution for drilling out broken bolts, where the left-hand flute direction can engage and back out a fastener during the drilling process. Covering a size range of 1/16 to 1/2 inch by 64ths, this 29-piece set addresses the full range of jobber-length drilling needs in a single kit.

Technical Specifications

Available Items

Unlike standard right-hand drill sets, the 200LH's left-handed flutes and cutting edges allow for counterclockwise rotation, which can simultaneously drill and back out broken fasteners — a capability no conventional right-hand drill set provides. The bright finish and 118° conventional point make this set particularly well suited to non-ferrous materials such as aluminum, while the jobber length provides the reach and versatility needed for the widest range of job-site applications.

Key Features & Benefits

Left-Handed Flutes and Cutting Edges

The left-handed flute geometry allows the drill to cut in a counterclockwise direction. This is essential for multiple spindle gear-driven drilling heads where adjacent spindles must alternate between left and right hand rotation, and for left hand screw machines.

Broken Bolt Removal Capability

Because the drill rotates counterclockwise, it can engage a broken bolt or stud during drilling and back it out of the hole. This eliminates the need for additional extraction tooling in many common fastener removal scenarios.

118° Conventional Point

The 118° conventional point geometry is optimized for rapid penetration into mild steels and free-machining materials. It is the standard point angle for general-purpose drilling and delivers reliable, consistent starts across a wide range of workpiece materials.

Bright Finish

The bright finish — a smooth, polished surface treatment with no additional coating — promotes increased chip flow and is ideal for drilling in non-ferrous materials such as aluminum. It reduces material adhesion and helps maintain a clean cutting edge during operation.

General Purpose HSS Construction

Made from general-purpose High Speed Steel, these drills are suitable for most materials including low to medium strength steels, aluminum, and other non-ferrous materials. HSS is the most widely used tool material for general-purpose drilling, offering a reliable balance of hardness and toughness.

Jobber Length

Jobber length is the most common drill length because it provides extra reach while remaining usable in the majority of drilling applications. This makes the 200LH set a versatile choice that can be deployed across a broad range of setups without requiring specialty extensions.

29-Piece Set, 1/16–1/2 by 64ths

The 29-piece set covers the full fractional range from 1/16 to 1/2 inch in 64th-inch increments, giving contractors and machinists a complete selection of left-hand drill sizes in a single kit. This eliminates the need to source individual left-hand drills for different hole sizes.

Common Applications

Broken Bolt and Stud Removal

The counterclockwise cutting action of the left-hand flutes can engage and back out broken bolts or studs during the drilling process, making this set a go-to tool for fastener extraction tasks.

Close-Center Multiple Spindle Gear-Driven Drilling Heads

These drills are specifically designed for use in close-center multiple spindle gear-driven drilling heads where adjacent spindles operate alternately left and right hand, requiring matched left-hand tooling.

Left Hand Screw Machines

The 200LH set is engineered for use in left hand screw machines, where counterclockwise spindle rotation demands left-handed cutting tool geometry.

Non-Ferrous Material Drilling

The bright finish is ideal for drilling aluminum and other non-ferrous materials, where the smooth polished surface reduces chip adhesion and promotes clean cutting.

Compatible Materials

• Non-ferrous materials (e.g., aluminum)
• Mild steels and free-machining materials (per 118° conventional point specification)
• Low to medium strength steels (per HSS material specification)

Product Documents

• Safety Data Sheet (SDS)
• Drillco Product Linecard

Safety Data Summary

Hazard Information

• During normal operation and usage, high speed steel products do not present inhalation, ingestion, or other chemical hazards.
• Operations such as grinding, cutting, machining, burning, and welding may release dusts, fumes, or vapors which may present health hazards if exposure limits are exceeded.
• Excessive inhalation of metallic fumes and dusts may result in irritation of eyes, nose, and throat; symptoms may include metallic taste, dryness and irritation of the throat, chills, and fever persisting 12 to 48 hours.
• Chromium is listed as a carcinogen by NTP and OSHA; various forms of dermatitis, inflammation and/or ulceration of the upper respiratory tract, and possibly cancer of nasal passages and lungs are associated with chromium exposure.
• Tungsten: some evidence of pulmonary involvement such as cough.
• Vanadium: eye and respiratory tract irritant.
• Cobalt dust is the most probable cause of respiratory diseases including occupational asthma and interstitial fibrosis.
• Skin contact can cause irritation or allergic skin rash due to cobalt sensitization.
• Eye contact may cause eye 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.

Personal Protective Equipment

• Wear safety glasses or goggles with side shields; contact lenses should not be worn 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 appropriate PEL or TLV.
• Hearing protection might be required.
• Always use machine guards and wear safety glasses and 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 to levels that do not exceed the PEL or TLV.
• 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 the end of the work shift.
• Do not shake clothing, rags, or other items to remove dust; remove dust by washing or vacuuming with appropriate filters.
• Clean up spills using methods to avoid dust generation such as vacuum (with appropriate filters), wet dust mop, or wet clean up.
• Soiled clothing should be laundered separately.
• Incompatible materials: strong acids, strong oxidizers.
• Speed, feed, and lubrication are all critical to cutting tool performance.

Frequently Asked Questions

Q: What is the primary purpose of a left-hand drill set like the 200LH?
A: The 200LH is designed for counterclockwise drilling operations, including use in close-center multiple spindle gear-driven drilling heads where adjacent spindles alternate left and right hand, in left hand screw machines, and for drilling out broken bolts.

Q: How does a left-hand drill help remove broken bolts?
A: Because the flutes and cutting edges are left-handed, the drill rotates counterclockwise. When drilling into a broken bolt, this counterclockwise rotation can engage the fastener and back it out of the hole during the drilling process.

Q: What size range does the 200LH29 set cover?
A: The 29-piece set covers 1/16 to 1/2 inch by 64ths of an inch.

Q: What materials are these drills best suited for?
A: The bright finish is ideal for drilling non-ferrous materials like aluminum. The HSS construction and 118° conventional point are suited for mild steels, free-machining materials, and low to medium strength steels.

Q: What point angle do these drills use, and why does it matter?
A: These drills feature a 118° conventional point, which is optimized for rapid penetration into mild steels and free-machining materials and is the standard geometry for general-purpose drilling applications.

Q: Are there any critical operating tips for getting the best performance from these drills?
A: Yes — speed, feed, and lubrication are all critical to cutting tool performance with these drills.