5 HSS Center Drill Cutter Bore Set 60° Combined Countersink #1 2 3 4 5
- Size: #1 – 5
- #1 center drill with 1/8″ body diameter & 3/64″ drill tip diameter & 1-1/4″ overall length
- #2 center drill with 3/16″ body diameter & 5/64″ drill tip diameter & 1-7/8″ overall length
- #3 center drill with 1/4″ body diameter & 7/64″ drill tip diameter & 2″ overall length
- #4 center drill with 5/16″ body diameter & 1/8″ drill tip diameter & 2-1/8″ overall length
- #5 center drill with 7/16″ body diameter & 3/16″ drill tip diameter & 2-3/4″ overall length
- ANSI Standard
- Body Tolerance: +.000″/-.001″
- Drill Tolerance: +.003″/-.000″
- Made of premium M2 High Speed Steel and ground finished, set comes complete withblister packingholding all 5 center drills
- Plain style 60° angle used for producing center holes in workpieces which require precision drilling or machining between centers. Also used as starter holes to prevent a drill bit from “walking”
Used for producing center holds in components or work pieces with require machining between centers
- HRC of HSS 6542 (W6Mo5Cr4V2)is 67~70. It is ideally designed for high production machine works in low and medium carbon steel, as well as non-ferrous material like aluminum, brass, bronze, and copper. And HSS 6542 has a good red-hardness and retains its cutting edge sharpness longer than other general purpose high speed steel. Its HRC retain 63~65 when the temperature reach 1112 F. HSS 6542 which has a melting point of 4724.6~4748 F. These bits will drill through the toughest steel like truck frames, stainless steel, farm implements, and more, very durable.
- 135° Self-centering Split Point prevents walking when starting a hole and is commonly on heavy duty tools.
- Black and gold finish
- Heavy duty drill bit usually combine a split point to prevent walking and stronger flute for better rigidity. Excellent choice for harder material.
- Please refer to the following 15/64″ (6mm) drill bit test report of HSS 6542 material. All drill bits imported from China are made of HSS 4241 or HSS 4341. HSS 6542 material is $1572/ton, and HSS 4241 material is $429/ton. The price of HSS 6542 material is 3.67 times higher than that of HSS 4241.
When the material of the workpiece is the same, the drill bit is worn after 74 holes are drilled with the15/64″ (6mm) drill bit made of HSS 4241. The drill bit is worn after 194 holes are drilled with the15/64″ (6mm) drill bit made of HSS 6542. The service life of the drill bit with the material of HSS 6542 is increased by 2.62 times and the cost is saved by 2.62 times.
- Workpiece material: SAE1045.
- Workpiece material hardness: HRC15
- Drilling Operation: blind hole drilling
- Drill Diameter: 15/64″
- Cutting Parameters: Vc=62 SFPM; fr=0.0078 in/r; H=0.826in
- Cooling System: water soluble cooling
- Conclusion: Shars industrial grade HSS6542 drill has performed 194 numbers of holes before showing normal wear while generic import grade HSS4241 tin coated drill from company A has performed 80 numbers of holes before showing edge chipping. Industrial grade M35 cobalt drill has performed 266 numbers of holes before showing normal wear.
- Grade HSS6542 and M35 drill set from Shars Tool has shown significant improvement in tool life than other generic import drills on the market.
- Better life improves machining efficiency.