NITRO® 350N Drill Bit — Heavy-Duty HSS Mechanics Length Drill for Medium and High Strength Materials
The DRILLCO NITRO® 350N is a mechanics length, NAS Type B high speed steel drill bit engineered for heavy-duty drilling in medium and high strength materials, including stainless steel. Built from premium quality M2 High Speed Steel with a Black & Gold surface treatment, it delivers superior performance over standard HSS drills in both handheld power tool and fixed spindle (CNC/drill press) applications. The 135° split point eliminates walking at startup, and the 3-flat shank prevents slippage in the drill chuck. Mechanics length construction provides better rigidity and accuracy in tighter spaces compared to jobber length alternatives.
Technical Specifications
| Specification | Details |
|---|---|
| Brand | DRILLCO |
| SKU | 350N104 |
| UPC | 045996999341 |
| Drill Type | NAS Type B |
| Series | 350N (Mechanic's Length) |
| Material | M2 High Speed Steel (HSS) |
| Finish / Surface Treatment | Black & Gold |
| Point Angle | 135° Split Point |
| Shank | 3-Flats |
| Length | 0.738 in |
| Width | 0.00157 in |
| Height | 0.00157 in |
| Weight | 0.0044 lbs |
| Country of Origin | United States |
| Applications | Drilling holes in medium and high strength materials, heavy-duty drilling, drilling in tighter spaces, drilling with handheld power tools |
| Compatible Operations | Portable hand drills, fixed spindle applications (CNC machines, drill presses) |
| Technical Tips | Speed, feed, and lube are all critical to cutting tool performance |
Available Sizes — 350N Series (Mechanic's Length)
The 350N series is available in a full range of fractional sizes. Sets also available: 350N29, 350NW29.
The NITRO® 350N mechanics length drill outperforms standard HSS drills through its premium M2 steel construction and Black & Gold surface treatment, which increases lubricity, resists corrosion and breakage, and reduces chipping and flaking. Unlike bright-finish or black oxide drills suited only for softer materials, the Black & Gold treatment allows use across most material groups, and the 135° split point self-centers on curved or hard surfaces where conventional 118° points would walk.
Key Features & Benefits
Premium M2 High Speed Steel Construction
All NITRO® drills are manufactured from premium quality M2 High Speed Steel, recommended for heavy-duty drilling across a wide range of material groups including stainless steel. M2 HSS provides the hardness and wear resistance needed to maintain cutting performance under demanding conditions.
Black & Gold Surface Treatment
The body and flute receive a Black & Gold surface treatment that maximizes lubricity while providing better resistance to corrosion and breakage. This treatment reduces chipping and flaking and allows the drill to perform on most materials, making it more versatile than black oxide or bright-finish alternatives.
135° Split Point
The 135° split point is self-centering, enabling faster penetration and eliminating the tendency to walk when starting a hole — especially valuable on curved surfaces or when drilling by hand. This reduces the need for a center punch in many applications and improves hole location accuracy.
3-Flat Shank
The 3-flat shank design prevents the drill from slipping in the chuck during high-torque drilling operations. This is particularly important for mechanics length drills used in handheld tools where chuck grip can be compromised by vibration or lateral forces.
Mechanics Length for Tighter Spaces
Shorter than jobber length drills, the mechanics length design provides better rigidity, improved accuracy, and reduced deflection and breakage risk. It is the preferred choice when working in confined or restricted-access areas where a full-length jobber drill cannot be used effectively.
Dual-Use Design — Handheld and CNC
The NITRO® 350N is designed for use in both portable handheld power drills and fixed spindle applications such as CNC machines and drill presses. This versatility makes it a practical stock item for shops and contractors who operate across multiple setups.
Common Applications
Drilling Medium and High Strength Steels
The M2 HSS construction and Black & Gold surface treatment make the 350N suitable for drilling into medium and high strength steel materials where standard HSS drills would wear prematurely.
Stainless Steel Drilling
NITRO® drills are specifically recommended for heavy-duty drilling in stainless steel, a material group that demands higher tool hardness and lubricity to prevent work hardening and premature wear.
Heavy-Duty Production Drilling
The combination of premium M2 steel, split point geometry, and Black & Gold treatment supports sustained heavy-duty drilling cycles in both handheld and CNC/drill press environments.
Drilling in Confined or Restricted Spaces
The mechanics length format is shorter than jobber length drills, making it the right choice when access is limited and a longer drill cannot be positioned or controlled safely.
Handheld Power Tool Operations
The 3-flat shank and split point design are specifically suited to handheld drilling, where chuck slippage and bit walking are common challenges on harder materials.
CNC and Drill Press Operations
The NAS Type B specification and rigid mechanics length make the 350N equally at home in fixed spindle CNC and drill press setups requiring consistent, repeatable hole quality.
Product Documents
Safety Data Summary
Hazard Information
- During normal operation, high speed steel products 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; symptoms include metallic taste, dryness and irritation of the throat, chills, and fever persisting 12–48 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 with dust can cause irritation or allergic skin rash due to cobalt sensitization.
- 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
- Gloves: Cloth or leather gloves recommended when contact with dust or mist is likely.
- Eye protection: Safety glasses or goggles with side shields; contact lenses should not be worn. Employer should provide an eye wash station within the immediate work area.
- Hearing protection may be required.
- Always use machine guards and wear safety glasses and protective clothing to prevent injury in the event of tool breakage.
- Respiratory protection: Use an appropriate NIOSH-approved respirator if airborne dust concentration exceeds the applicable PEL or TLV, per 29 CFR 1910.134.
- Soiled clothing should be laundered separately.
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.
- Incompatible materials: Strong acids, strong oxidizers.
- Emergency phone: CHEM-TEL INC 1-800-255-3924.
Frequently Asked Questions
Q: What materials is the NITRO® 350N designed to drill?
A: The 350N is recommended for heavy-duty drilling in a wide range of material groups, including medium and high strength steels and stainless steel. The Black & Gold surface treatment allows use on most materials.
Q: What is the difference between the 350N (Mechanic's Length) and the 400N (Jobber Length)?
A: The 350N is a mechanics length drill, which is shorter than the jobber length 400N. Shorter drills provide better accuracy, are more rigid, and are better suited for drilling in tighter, more confined spaces, while also mitigating deflection and breakage.
Q: Can the 350N be used in both handheld drills and CNC machines?
A: Yes. The NITRO® 350N is designed for use in portable handheld power drills as well as fixed spindle applications including CNC machines and drill presses.
Q: Why does the 350N have a 3-flat shank?
A: The 3-flat shank reduces slippage in the drill chuck, which is especially important during high-torque or handheld drilling operations where a round shank could spin in the chuck.
Q: What does the 135° split point offer over a standard 118° conventional point?
A: The 135° split point is self-centering, allowing faster cutting and less walking when starting a hole. It is particularly effective on curved surfaces and for hand-drilling on harder materials, reducing or eliminating the need for a center punch.
Q: Are cutting lubricants recommended with the 350N?
A: Yes. Speed, feed, and lubrication are all stated as critical to cutting tool performance. The product sheet notes that using metal cutting lubricants can increase drill life significantly by deflecting heat during the machining operation.