Carbide drill bits

KERNVEX Interal Cooling 2 Flutes High Speed Drills

Range reference: KVX-005

workpiece material: Soft steel; Hardened and tempered steel; Tempering stainless steel; Cast iron; Bearing steel; Deep hole working
application type: Drilling
Coating: Self development comparable to DR coating

• Material: MG-grade carbide rods,ultra-fine grain size 0.8um，10% Coblat • Coating: Self-develped coating (benchmarking B-a-l-z-a-s DR Coating) • Coating hardness: 2000-4000HV • Ultra-low friction coefficient:0.05-0.15 • Helix angle: 30° • Point angle:138.9° • Large rake angle: 16° • Negative chamfer: -6° • Variable core thickness: 30–40% • Variable outer diameter: 0.8°

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Technical data

Product Name	Internal Coolant Drill Bit
Material	Solid carbide
Process	Fully Gorund (Roll Forged & Polished, Roll Forged, Milled are Available)
Size	Standard size or as request
Point Type	118 Degree Regular Point (1-3mm); 138 Degree Split Point(3-20mm)
Shank Type	Straight Shank (Tree Flats Shank, 1/2" Shank Sliver & Deming, Reduced Shank,1/4" Quick Change Hex Shank are Available)
Surface Finish	Amber Color (Bright, Black Oxide, Titanium, Black & Gold, are Available)
Package	Plastic Box or as request

Additional technical data

Product Code	Blade diameter	Blade Length H			Full L			Shank D
Product Code	Blade diameter	3XD	5XD	8XD	3XD	5XD	8XD	3XD	5XD	8XD
EXNJ00400	4	24	36	43	66	74	81	6	6	6
EXNJ00450	4.5	24	36	43	66	74	81	6	6	6
EXNJ00500	5	28	44	57	66	82	95	6	6	6
EXNJ00550	5.5	28	44	57	66	82	95	6	6	6
EXNJ00600	6	28	44	57	66	82	95	6	6	6
EXNJ00650	6.5	34	53	76	79	91	114	8	8	8
EXNJ00700	7	34	53	76	79	91	114	8	8	8
EXNJ00750	7.5	41	53	76	79	91	116	8	8	8
EXNJ00800	8	41	53	76	79	91	116	8	8	8
EXNJ00850	8.5	47	61	95	89	103	142	10	10	10
EXNJ00P00	9	47	61	95	89	103	142	10	10	10
EXNJ00950	9.5	47	61	95	89	103	142	10	10	10
EXNJ01000	10	47	61	95	89	103	142	10	10	10
EXNJ01050	10.5	55	71	114	102	118	162	12	12	12
EXNJ01100	11	55	71	114	102	118	162	12	12	12
EXNJ01150	11.5	55	71	114	102	118	162	12	12	12
EXNJ01200	12	55	71	114	102	118	162	12	12	12
EXNJ01250	12.5	60	77	133	107	124	178	14	14	14
EXNJ01300	13	60	77	133	107	124	178	14	14	14
EXNJ01350	13.5	60	77	133	107	124	178	14	14	14
EXNJ01400	14	60	77	133	107	124	178	14	14	14
EXNJ01450	14.5	65	83	152	115	133	204	16	16	16
EXNJ01500	15	65	83	152	115	133	204	16	16	16
EXNJ01550	15.5	65	83	152	115	133	204	16	16	16
EXNJ01800	16	65	83	152	115	133	204	16	16	16
EXNJ01850	16.5	73	93	171	123	143	223	18	18	18
EXNJ01700	17	73	93	171	123	143	223	18	18	18
EXNJ01750	17.5	73	93	171	123	143	223	18	18	18
EXNJ01800	18	73	93	171	123	143	223	18	18	18
EXNJ01850	18.5	79	101	-	131	153	-	20	20	20
EXNJ01900	19	79	101	-	131	153	-	20	20	20
EXNJ01950	19.5	79	101	-	131	153	-	20	20	20
EXNJ02000	20	79	101	-	131	153	-	20	20	20

Additional technical data

Item	Internal Coolant Drill	External Coolant Drill
Coolant Supply	Coolant flows through internal channels directly to the cutting edge	Coolant supplied externally by machine nozzles
Visual Apperance	Visible coolant holes on the drill body	Solid body, no visible holes
Chip Evacuation	Excellent	Limited
Suitable Drillling Depth	5XD,8XD,12XD,up to 30XD	Typically≤3XD
Cutting Stability	Very high, minimal vibration	Reduced stability in deep holes
Cooling Efficiency	Direct cooling at cutting zone	Cooling easily blocked by chips
Machine Requirement	Must support internal coolant	Standard machines supported

Technical notes

This internal coolant solid carbide drill is designed for high-efficiency deep hole drilling and demanding cutting conditions.
Ideal for deep hole machining, high-speed cutting, and difficult-to-machine materials.
1. Premium Carbide Substrate
• Made from imported MG-grade carbide rods
• Ultra-fine grain size: 0.8μm
• 10% cobalt content for balanced toughness and wear resistance
• Excellent adaptability to high-speed and high-feed drilling
This substrate ensures strong edge stability while maintaining sharpness during long cutting cycles.
(Benchmarking B-a-l-z-a-s DR Coating)
• Proprietary coating independently developed in-house
• After edge passivation post-treatment
• Coating hardness: 2000–4000 HV
• Ultra-low friction coefficient: 0.05–0.15
• Significantly reduces:
• Edge chipping
• Adhesion and scratching
The coating effectively extends tool life and ensures stable performance in continuous deep hole drilling.
3. Optimized Drill Geometry Design
Advanced Point & Cutting Edge Design
• Point angle: 138.9°
• Double cutting lip design:
• Primary cutting edge ensures cutting efficiency
• Secondary cutting edge improves wear resistance and chip breaking
• Equalized web design with angular offset
• Forms a chip-splitting point structure
• Prevents drill wandering
• Enables fast material engagement and stable positioning
This geometry allows smooth cutting and precise hole accuracy even in deep drilling applications.
4. High-Efficiency Flute & Core Design
This flute structure significantly improves:
• Chip evacuation
• Cutting stability
• Tool rigidity during deep hole drilling
5. Wide Application Range
Suitable for machining:
• Quenched & tempered steel
• Quenched & tempered stainless steel
• Bearing steel
• Deep hole drilling applications
Technical Comarison
How to Choose the Right Drill?
✔ Choose an Internal Coolant Drill when:
• Drilling depth is ≥ 5×D
• Machining stainless steel or alloy steel
• High requirements for tool life and hole accuracy
• High-speed, continuous CNC production
✔ Choose an External Coolant Drill when:
• Drilling depth is ≤ 3×D
• Machining aluminum or mild steel
• Machine does not support internal coolant
• Cost-sensitive applications
2.Self-Developed High-Performance Coating
Helix angle: 30°
Large rake angle: 16°
Negative chamfer: -6°
Variable core thickness: 30–40%
Variable outer diameter: 0.8°