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Premium M35 & M42 Cobalt Drill Bits for Stainless Steel
Premium M35 & M42 cobalt (HRC 65–67) delivers 2–3 longer tool life than standard HSS drill bits when drilling stainless steel
Fast delivery: Sufficient stock available, with fast delivery in 15–25 days to ensure reliable bulk supply
Strict QC on each batch (hardness + angle test) reduces complaints and ensures consistent repeat orders
MOQ 100 pcs with sample support, helping buyers quickly test market demand with low risk
15+ years of export experience supporting importers, wholesalers, and OEM brands worldwide
Trusted by Global Brands
OEM Partner for Industry Leaders
Customization & Packaging
Complete OEM/ODM solutions tailored to your brand requirements
Build Your Own Brand with Custom
- Custom Size Options (0.5mm–20mm / 1/64”–25/32”)
- Shank Type Customization Straight shank / Reduced shank (9mm, 13mm, 3/8", 1/2" Silver & Deming) / 1/4" Hex / Three flats — fit different drilling machines and markets
- Material Selection HSS 4241 / 4341 / 6542 / M35 / M42 — tailored to your target price and performance level
- Laser Marking & Branding Custom logo, size marking, and surface finish — build your private label with clear product identity
Application Notes
Discover the versatile applications and material compatibility of our products
Drilling Aluminum
- •Suitable for aluminum sheets, profiles, and non-ferrous metals
- •Material sticking, poor chip evacuation, and fast edge wear reduce efficiency.
- •TENYU Premium M35 & M42 Cobalt Drill Bits ensure smooth chip removal, fast drilling speed, and longer tool life for high-volume operations.
Drilling Copper
- •Suitable for ideal for copper, brass, and soft conductive metals.
- •Soft materials cause clogging and deformation, affecting hole accuracy and surface finish.
- •Our cobalt drill bits deliver clean cutting edges and stable performance, minimizing burrs and improving precision for consistent batch production.
Drilling Stainless Steel
- •Suitable for stainless steel, alloy steel.
- •Work hardening, overheating, and rapid tool wear lead to frequent replacements and higher costs.
- •TENYU Premium M35 & M42 Cobalt Drill Bits provide superior heat resistance (HRC 65–67), maintaining sharpness under high temperatures and ensuring efficient, long-lasting drilling performance.
Real Factory & Application Videos
Watch real manufacturing and field applications to verify quality, performance, and supply capability
Need Stable HSS Drill Bits for Bulk Orders?
TENYU HSS twist drill bits are designed for drilling mild steel, aluminum, copper, wood, and plastic, ideal for importers, wholesalers, and tool distributors seeking stable quality, OEM branding, and reliable bulk supply.
How Does Our Factory Ensure Stable Quality HSS Twist Drill Bits for Bulk Orders?
Compatible with handheld drills and machines, delivering consistent drilling performance across large batches. With strict QC (hardness + cutting tests), flexible packaging, and 15–25 days delivery, we help importers secure reliable supply and grow their market with confidence.
Why Do Global Wholesalers Choose Our HSS Twist Drill Bits for Mild Steel & Aluminum?
Engineered for fast, clean drilling in mild steel, aluminum, copper, and plastic, with controlled hardness and precision grinding. We help wholesalers reduce breakage, improve hole accuracy, and minimize complaints, while supporting OEM packaging and stable bulk supply for repeat orders.
Our Production Process
From raw materials to finished products, every step is meticulously controlled to ensure superior quality and precision.
Raw Material Cutting
Heat Treatment
Coarse Grinding
Shank Grinding
Flute Edge Grinding
Fine Grinding
Double Angle
Angle Grinding
Sharping Edge
International Certifications
Our products meet the highest international standards and are certified by leading quality organizations worldwide.
RoHS Certificate
• Expiry Date:2027.10.05
ISO 9001:2015
• Expiry Date:2028.10.05
SGS Audit Report
• Expiry Date:2028.01.05
Product Spec Table
| SKU | Key Specs | Material / Coating | Packaging |
|---|---|---|---|
| 1/64"/0.5mm | 12mm Flute Length / 34mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 3/64"/1.0mm | 12mm Flute Length / 34mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 1/16"/1.5mm | 20mm Flute Length / 43mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 5/64"/2.0mm | 24mm Flute Length / 49mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 3/32"/2.5mm | 30mm Flute Length / 57mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 7/64"/3.0mm | 33mm Flute Length / 61mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 9/34"/3.5mm | 39mm Flute Length / 70mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 5/32"/4.0mm | 43mm Flute Length / 75mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 11/64"/4.5mm | 47mm Flute Length / 80mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 3/16"/5.0mm | 52mm Flute Length / 86mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 7/32"/5.5mm | 57mm Flute Length / 93mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 15/64"/6.0mm | 57mm Flute Length / 93mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 1/4"/6.5mm | 63mm Flute Length / 101mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 17/64"/7.0mm | 69mm Flute Length / 109mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 9/32"/7.5mm | 169mm Flute Length / 101mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 5/16"/8.0mm | 75mm Flute Length / 117mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 21/64"/8.5mm | 75mm Flute Length / 117mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 11/32"/9.0mm | 81mm Flute Length / 125mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 3/8"/9.5mm | 81mm Flute Length / 125mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 25/64"/10.0mm | 87mm Flute Length / 133mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 13/32"/10.5mm | 87mm Flute Length / 133mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 27/26"/11mm | 94mm Flute Length / 142mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 7/16"/11.5mm | 94mm Flute Length / 142mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 15/32"/12mm | 101mm Flute Length / 151mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 31/64"/12.5mm | 101mm Flute Length / 151mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 1/2"/13.0mm +mm | 101mm Flute Length / 151mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 17/32"/13.5mm | 108mm Flute Length / 160mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 9/16"/14.0mm | 108mm Flute Length / 160mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 37/64"/14.5mm | 114mm Flute Length / 169mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 19/32"/15.0mm | 114mm Flute Length / 169mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 39/64"/15.5mm | 120mm Flute Length / 178mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 5/8"/16.0mm | 120mm Flute Length / 178mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 21/32"/16.5mm | 125mm Flute Length / 184mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 43/64"/17.0mm | 125mm Flute Length / 184mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 11/16"/17.5mm | 130mm Flute Length / 191mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 45/64"/18.0mm | 130mm Flute Length / 191mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 47/64"/18.5mm | 135mm Flute Length / 198mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 3/4"/19.0mm | 135mm Flute Length / 198mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 49/64"/19.5mm | 140mm Flute Length / 205mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
| 25/32"/20.0mm | 140mm Flute Length / 205mm Overall Length | M35/M42 Body Material/Custom Coated | Plastic Box/Paper Box/Customization |
Frequently Asked Questions
Everything you need to know about our products, customization options, and ordering process.
What does HSS mean on a drill bit?
HSS stands for High-Speed Steel. It is a carbon steel alloyed with elements such as tungsten, molybdenum, chrome, and vanadium. Unlike standard carbon steel, HSS is designed to maintain its hardness at high temperatures (red-hardness), allowing the drill bit to rotate at higher speeds without losing its cutting edge.
What is an HSS twist drill bit used for?
HSS drill bits deliver fast, precise drilling in metal (aluminum, copper, brass, mild steel), plastic, and wood, offering heat resistance, durability, and stable cutting performance.
Can I use an HSS drill bit for masonry?
No. We do not recommend using standard HSS bits for masonry (concrete, brick, or stone). • The Reason: Masonry requires a percussion (hammer) action and a specialized Tungsten Carbide Tip (TCT). • The Risk: Using an HSS bit on concrete will cause the cutting edge to overheat and dull almost instantly, potentially damaging your workpiece and the drill.
What is the meaning of HSS-Co (Cobalt) drill bits?
HSS-Co drill bits (5–8% cobalt) deliver high heat resistance and durability, ideal for drilling stainless steel, cast iron, and hard metals..They maintain their cutting edge at high temperatures, allowing faster, more efficient drilling compared to standard HSS bits, though they are more brittle and expensive.
What is the difference between HSS and HSS CO?
Cobalt drill bits offer higher hardness and heat resistance than standard HSS, enabling longer continuous drilling and stable performance in heavy-duty applications.
What are the disadvantages of cobalt drill bits?
Cobalt drill bits are durable but brittle; misalignment, excessive force, or dropping can cause chipping or breakage.
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Trusted by businesses worldwide
See what our global partners say about our premium drilling tools and cutting solutions.
"Our manufacturing line requires constant drilling of heavy-duty materials like die steel and thick steel plates, alongside our standard stainless steel components. TENYU's Premium M35 & M42 Cobalt Drill Bits handle these with incredible precision and speed. The heat resistance is unmatched. After watching the detailed factory introduction of TENYU's automated production facility, we were fully convinced of their consistency. TENYU will absolutely be our long-term supplier. This is a highly recommended factory for any heavy industry applications."
Park Ji-hoon
Production Manager
South Korea
"As a specialized pump manufacturer, we process a wide mix of metals, including massive cast iron casings, copper alloys for impellers, and stainless steel shafts. TENYU’s Premium M35 & M42 Cobalt Drill Bits provide the versatile performance we demand. The M35s are workhorses for cast iron, while the M42s are superb on stainless. Our vendor assessment team was impressed by TENYU’s factory introduction, especially their testing lab. We have officially selected TENYU as our long-term supplier. A highly reliable and recommended factory."
Marek Kowalski
Head of Supply Chain
Poland
"Precision and cycle time are critical for our Tier-1 automotive components. We use TENYU's Premium M35 & M42 Cobalt Drill Bits to drill hundreds of thousands of holes annually, ranging from specialized aluminum brackets to die steel fixtures and stainless steel fuel system parts. Their consistency across materials is remarkable. The transparent factory introduction showcasing TENYU’s 20-year expertise solidified our confidence. They will definitely be our long-term supplier. For any brand looking to upscale their product line with solid industrial muscle, TENYU is a highly recommended factory."
Sofia Rodriguez
Lead Engineer
Mexico
"Our manufacturing line requires constant drilling of heavy-duty materials like die steel and thick steel plates, alongside our standard stainless steel components. TENYU's Premium M35 & M42 Cobalt Drill Bits handle these with incredible precision and speed. The heat resistance is unmatched. After watching the detailed factory introduction of TENYU's automated production facility, we were fully convinced of their consistency. TENYU will absolutely be our long-term supplier. This is a highly recommended factory for any heavy industry applications."
Park Ji-hoon
Production Manager
South Korea
"As a specialized pump manufacturer, we process a wide mix of metals, including massive cast iron casings, copper alloys for impellers, and stainless steel shafts. TENYU’s Premium M35 & M42 Cobalt Drill Bits provide the versatile performance we demand. The M35s are workhorses for cast iron, while the M42s are superb on stainless. Our vendor assessment team was impressed by TENYU’s factory introduction, especially their testing lab. We have officially selected TENYU as our long-term supplier. A highly reliable and recommended factory."
Marek Kowalski
Head of Supply Chain
Poland
"Precision and cycle time are critical for our Tier-1 automotive components. We use TENYU's Premium M35 & M42 Cobalt Drill Bits to drill hundreds of thousands of holes annually, ranging from specialized aluminum brackets to die steel fixtures and stainless steel fuel system parts. Their consistency across materials is remarkable. The transparent factory introduction showcasing TENYU’s 20-year expertise solidified our confidence. They will definitely be our long-term supplier. For any brand looking to upscale their product line with solid industrial muscle, TENYU is a highly recommended factory."
Sofia Rodriguez
Lead Engineer
Mexico
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