Best HSS Drill Bits for Hard Metals and DIY Projects
Finding the right HSS drill bits means balancing hardness, heat resistance, and durability for materials ranging from stainless steel to aluminum. This guide highlights five top HSS cobalt drill sets that combine titanium coatings, cobalt alloys, and precision tips to deliver cleaner holes with less wandering. Each product is chosen for versatility, reliability, and value. Review the quick-summary table below, then explore detailed sections for each option. A Buying Guide follows to help you compare alloy content, point geometry, and shank compatibility so you can pick the best fit for your workshop.
| Product | Brand | Notable Feature |
|---|---|---|
| IRONANT Step Drill Bits | IRONANT | 50 Sizes In 5 Pieces; HSS Titanium Coating; 118° Split Point |
| HIDOTOL 13 PCS Cobalt Set | HIDOTOL | 135° Split Point; M35 Cobalt; Self-Centering Design |
| NewShark M35 Cobalt Drill Bits | NewShark | 19 Pieces; 5% Cobalt; Metric Range 1–10 mm |
| BOSCH CO14B 14-Piece Set | Bosch | M42 Cobalt; Three-Flat Shank; High Heat Resistance |
| GMTOOLS 13Pcs Cobalt Bits | GMTOOLS | 135° Point; M35 Cobalt; Includes Storage Case |
IRONANT Step Drill Bits Review
The IRONANT set is designed for versatility when drilling metal and aluminum. The five-piece kit includes a total of 50 step sizes, enabling quick size changes without swapping bits frequently. A titanium coating enhances sharpness and durability, while the 118-degree split-point tip offers self-centering that reduces wandering and improves hole accuracy. The dual-flute design promotes faster chip clearance, helping to keep temperatures manageable during longer drilling sessions. The kit includes an aluminum case for organized storage and portable use in DIY shops and professional garages.
- HSS Titanium coating boosts wear resistance and longevity.
- 118° split-point tip ensures self-centering and faster starts.
- 50 sizes spread across 5 standard bits for broad versatility.
- Clearance and chip removal improve with the dual-flute design.
Ideal applications include metal fabrication, HVAC work, and light aluminum work where a wide range of hole sizes is needed without changing bits often. While the titanium coating improves durability, users should still avoid tapping too aggressively on hard metals to prevent edge chipping and reduce bit life over time. Overall, the IRONANT set pairs practicality with broad applicability for DIY enthusiasts and professionals who value convenience and coverage in a single kit.
HIDOTOL 13-Piece Cobalt Drill Bits
The HIDOTOL set leverages M35 cobalt alloy to extend tool life when drilling hard metals, including stainless steel and cast iron. Each bit features a 135-degree split point with a round straight shank to improve self-centering and reduce walking. The fully ground twist design helps optimise chip clearance, thereby reducing friction and heat buildup for cooler drilling performance. This set is particularly suitable for tough materials where standard high-speed steel bits wear quickly, delivering improved durability and consistent performance across tasks ranging from metalwork to complex plastics and wood applications.
- M35 cobalt alloy provides enhanced wear resistance and heat tolerance.
- 135° split point minimizes wandering and improves accuracy.
- Fully ground twist design aids chip removal and cool operation.
- Wide material compatibility including hardened metals and plastics.
Sizes range from 1/16″ to 1/4″, organized in a sturdy case for easy transport and quick access on the job. While the cobalt content improves longevity, operators should use appropriate feeds and speeds to maximize life in stainless and other hard metals. This set is a strong option for workshop kits that prioritize durability and straightforward usage across common metalworking tasks.
NewShark M35 Cobalt Drill Bits
The NewShark set delivers a metric-focused collection (1 mm to 10 mm) with 19 bits crafted from M35 cobalt steel, offering enhanced wear resistance and heat tolerance suitable for hard metals. The 5% cobalt content increases cutting efficiency and longevity under demanding drilling conditions. A 135-degree tip provides rapid penetration, while the straight shank helps with stable grip and reduced walking. The bits are housed in a durable storage case that aids in transport and organization for job sites or workshops that require precise metric increments.
- 19-piece metric set with 1 mm to 10 mm range.
- 5% cobalt content for improved durability and faster cutting.
- 135° split point with straight shank for accuracy and speed.
- Jobber-length design suitable for metal, plastics, and wood.
Applications span stainless steel, hardened metals, and alloy work where precise metric sizing is essential. While cobalt-based bits deliver longer life, users should monitor heat buildup during high-speed drilling in very thick materials. The NewShark set provides reliable performance and portability for professional use and serious hobbyist projects alike.
Bosch Cobalt CO14B 14-Piece Set
The Bosch CO14B set centers on M42 cobalt alloy, offering extended bit life and robust performance in stainless steel, cast iron, titanium, and light-gauge metals. The M42 alloy includes about 8% cobalt, delivering significant wear resistance and heat tolerance for demanding drilling tasks. A highlight feature is the three-flat shank design, which improves grip and reduces slippage in high-torque situations. This is a premium choice for professionals who frequently work with tough metals and require dependable, long-lasting bits supported by a recognized brand reputation.
- M42 cobalt alloy with enhanced wear life.
- 8% cobalt content for high heat resistance.
- Three-flat shank for solid bit retention and torque transfer.
- 14 pieces cover a wide range of hole sizes.
Ideal for stainless steel, cast iron, titanium, and aluminum drilling where accuracy and longevity matter. The CO14B’s quality materials and design justify its position in professional toolboxes, especially for fabricators and metalworkers who demand consistent results across repeated tasks. Users should pair these bits with appropriate feeds and speeds to maximize performance and minimize wear over time.
GMTOOLS 13-Piece Cobalt Bits
The GMTOOLS set comprises 13 pieces of cobalt-containing HSS bits designed for hardened metals, stainless steel, and cast iron. With a 135-degree split point, bits auto-center, reducing walking and enabling quicker starts. The universal round shank ensures compatibility with a wide range of tool holders, while the 6542 high-speed steel core adds toughness. The 5% cobalt alloy improves wear resistance and durability, helping the bits stay sharp longer under demanding drilling conditions. A sturdy storage solution keeps everything organized for workshop use.
- 13-piece cobalt drill bit set with M35 alloy (5% cobalt).
- 135° split point for fast, accurate starts.
- Universal round shank supports multiple holder types.
- Sturdy case for easy transport and storage.
These bits are suitable for metalworking projects that require consistent performance across a family of sizes. The balance between cutting speed and life makes GMTOOLS a practical choice for general purpose metal fabrication, where dependable bits can improve throughput and reduce downtime between holes. When drilling very hard metals, use appropriate lubrication and vary speeds to maintain edge integrity and prolong life.
Buying Guide
Choosing the right HSS drill bits depends on material, work intensity, and the kind of hole you need. Here are key purchase considerations with clear comparisons to help you decide which set best fits your shop.
- Material and cobalt content: M35 cobalt (5%) improves wear resistance and heat tolerance, while M42 cobalt (8%) offers greater longevity in hard metals. Sets like HIDOTOL and GMTOOLS leverage M35, while the Bosch CO14B relies on M42 for extended life in stainless steel and titanium.
- Coating and heat management: Titanium coating on HSS bits reduces friction and preserves edge sharpness during repeated drilling. Titanium-coated and cobalt-enhanced sets are generally better for tough metals than standard HSS bits.
- Tip geometry: 135-degree split point is common and assists self-centering and fast penetration, minimizing wandering. Some sets feature 118-degree tips for different material responses; choose based on the metals you most frequently drill.
- Shank design: Round straight shanks are compatible with most drill chucks, while specialized designs like three-flat shanks improve torque transfer in high-torque applications. Confirm your drill’s collet or chuck compatibility when selecting.
- Set size and coverage: If you work with many hole sizes, consider a set with broad size coverage, such as 1 mm to 10 mm in metric or 1/16″ to 1/4″ in fractional inches. Some kits offer 50 sizes across fewer bits, which is convenient for DIY tasks; others provide extensive collections for professional shops.
- Durability and heat resistance: For frequent drilling in stainless steel or hardened metals, cobalt alloys (M35 or M42) offer superior life and heat resistance compared with standard HSS. Plan for the types of metals you encounter most to determine the ideal cobalt content.
- Practical factors: Storage cases help with organization, especially on job sites. If you rotate through many sizes, a compact case with labeled bits can save time and prevent misplacement.
Comparison Snapshot
| Aspect | IRONANT | HIDOTOL | NewShark | BOSCH CO14B | GMTOOLS |
|---|---|---|---|---|---|
| Alloy | HSS with titanium coating | M35 cobalt | M35 cobalt | M42 cobalt | M35 cobalt |
| Tip | 118° split point | 135° split point | 135° split point | Standard/three-flat | 135° split point |
| Size Range | 50 total sizes | 1/16″–1/4″ | 1–10 mm | 14 pieces | 1/16″–1/4″ |
| Shank | Standard | Round straight | Straight | Three-flat | Round |
| Best For | General metal and DIY | Hardened metals, stainless | Metric drilling | Stainless, high heat | Versatile metals |
When choosing, consider the metals you most frequently drill, the size range you’ll use, and whether a storage case helps keep your workspace organized. For frequent work with hardened metals or stainless steel, cobalt content (M35 or M42) and proper heat management are key. If you need broad size coverage in a compact kit, a 14-piece set with M42 cobalt may be advantageous. For DIY projects and light fabrication, a kit with more sizes and a titanium coating can provide excellent value. Always follow manufacturer recommendations for feeds and speeds to maximize bit life and drilling performance.