Answering the common search for a high-quality 0.339 inch drill bit, this guide highlights five top picks suitable for metal, wood, and plastic projects. Each product case explains who it’s best for, why it was chosen, and any practical caveats. This selection helps DIYers, professionals, and hobbyists choose the right bit based on material, coating, and precision needs.
- Product suitability table: MAXTOOL 0.339″ HSS vs competitors by material and coating
- Best overall for metalworking: balanced hardness, sharpness, and durability
- Best value option: economical bits with solid performance
- Best for stainless steel or hard metals: cobalt or coated variants
- Best for precision and reduced walking: precision-ground tips
Product Comparison Snapshot
| Product | Material/Coating | Tip Type | Best For |
|---|---|---|---|
| MAXTOOL Letter R 2pcs 0.339″ HSS Drill Bits | High Speed Steel | Fully ground | Metal, plastic, wood cutting; long life |
| Topline USA Drill Bit Size Q M42 Cobalt | Cobalt (M42) | Standard twist | Stainless steel and hard metals |
| Century Drill & Tool 11433 #33 Wire Gauge | Standard HSS | 118° ground tip | General purpose wood, metal, plastic |
| uxcell 8.5mm 0.335″ Jobber Bits | HSS with black nitride & gold Ti coating | 135° split point | Stainless steel, aluminum, alloy metals |
| Meccion M35 Cobalt 33/64″ TiAIN | Cobalt with TiAIN coating | 135° pilot point | Metal, stainless steel, cast iron |
MAXTOOL Letter R 0.339″ HSS Drill Bits
Product: MAXTOOL Letter R 2pcs Identical Jobber Length Drills Dia 0.339″ HSS M2 Twist Drill Bits Fully Ground Black-Bronze Straight Shank Drills; JBL02H10RRP2
Key features: Jobber length, straight shank; suitable for cutting metal, plastic, and wood; high speed steel for hardness and cutting efficiency; long tool life; conforms to ASME/ANSI B94.11M or USCTI standards.
Best for: General metalworking and mixed-material projects where a reliable 0.339″ bit is needed. The straight shank and full ground tip support precise starts and clean holes.
Why chosen: Strong balance of hardness, durability, and universal compatibility with common drill equipment. The 0.339″ size is a precise mid-range that fits many projects. A potential limitation: not the best choice for extreme deep drilling in very tough alloys without adequate lubrication.
TopLine USA Drill Bit Size Q M42 Cobalt
Product: Topline USA Drill Bit Size’Q’ M42 Cobalt 1-Pk
Key features: Cobalt alloy (M42) for improved heat resistance and hardness; single bit in size Q.
Best for: Hard metals and stainless steel applications where heat buildup is a concern. The cobalt coating helps maintain edge sharpness under tough drilling conditions.
Why chosen: Cobalt bits excel in metal-on-metal drilling. Limitation: one-piece bit means no spare if you lose or dull it in a project; not ideal for softer materials where standard HSS is sufficient.
Century Drill & Tool 11433 #33 Wire Gauge
Product: Century Drill & Tool 11433 Wire Gauge Drill Bit, #33
Key features: 118-degree ground tip for clean starts and reduced bit walking; versatile for wood, metal, and plastic; compatible with drill presses and handheld drills.
Best for: Professionals and DIYers who require consistent performance across materials with reliable starting accuracy.
Why chosen: The 118° precision-ground tip minimizes wandering on initial contact. Caution: the wire gauge designation is narrow; ensure the drill’s chuck and speed settings suit this specific size for best results.
uxcell 8.5mm Jobber Bits with Dual Coating
Product: uxcell 2pcs Jobber Drill Bits 8.5mm (0.335″) Black Nitride & Gold Titanium Coated M2
Key features: 0.335″ size with dual coatings for lubrication, corrosion resistance, and durability; 135-degree split point; suitable for metals including stainless steel and aluminum.
Best for: Users needing smoother cutting and reduced chip clogging in harder metals and alloys; good option for grinding precision in repeated tasks.
Why chosen: Dual coatings improve life and cutting efficiency. Limitation: slightly smaller than 0.339″ target size; verify tolerance for tight-fitting holes in critical projects.
Meccion M35 Cobalt Drill Bits 33/64″ TiAIN
Product: Meccion M35 Cobalt Drill Bits 33/64 Inch TiAIN HSS Drill Bit for Metal
Key features: 5% cobalt HSS with TiAIN coating; hardness up to HRC 67; 135-degree pilot point; straight round shank with 3 flat design for firm clamping and concentric drilling.
Best for: Drilling through tough metals like stainless steel and cast iron where heat and wear resistance are crucial.
Why chosen: High cobalt content and TiAIN coating extend life under demanding metalwork. Caution: diameter is quite small; verify hole size and tolerance for your project to avoid under-sizing.
Buying Guide
What to consider when choosing a 0.339 inch drill bit:
- Material compatibility: Choose HSS for general use; cobalt variants for hard metals; coatings improve wear resistance and lubrication.
- Tip geometry: 118° or 135° points reduce walking; pilot points help start holes accurately.
- Shank type: Straight shank is common for most drills; consider a split point or 3-flat shank for better grip in some setups.
- Coatings: Black nitride and TiAIN coatings extend life and reduce friction; confirm compatibility with your drill chuck and machine.
- Size tolerance: Verify that 0.339″ fits your intended hole size precisely; small variances can affect fit in precision assemblies.
- Use case: General purpose projects benefit from versatile HSS bits; stainless steel and cast iron demand cobalt or coated variants.
Frequently Asked Questions
- What is the advantage of a cobalt drill bit for metalworking?
Co cobalt bits resist heat better, stay sharp longer, and perform well in hard metals like stainless steel.
- Is a 0.339″ drill bit common for woodworking?
Yes, but it is primarily used for metal and plastic; wood drilling is common with HSS bits in this size range.
- What does a 135-degree point indicate?
It indicates the angle of the cutting tip. A 135-degree point can reduce walking on tough or hard surfaces.
- Can I use these bits in a hand drill or drill press?
All listed bits are designed for use in both handheld drills and drill presses, depending on shank compatibility and machine power.
- Do coatings affect hole quality?
Coatings mainly reduce wear and friction, helping maintain edge sharpness and hole accuracy over time.