PATIKIL #21 Drill Bit, Micro Number Small Bits 4341 High-Speed Steel 135° Gold Finish for Soft Thin Metal Steel Wood Acrylic - 5 Pack

PATIKIL #21 Drill Bit, Micro Number Small Bits 4341 High-Speed Steel 135° Gold Finish for Soft Thin Metal Steel Wood Acrylic - 5 Pack

PACKING LIST: 5 packs of drill bits in #21 (4.039mm) cutting diameter, 55mm/2.17inch flute length, 83mm/3.27inch overall length, 135° point tip. FEATURE: 4341 High-Speed Steel (HSS) Twist Drills excel in medium-low speed, high-impact, and cost-sensitive applications.​ The Gold finish can further enhance the drill bit's wear and corrosion resistance, thereby extending its service life. APPLICATION: The #21 drill bit delivers superior all-around performance, making it the optimal choice for most metal drilling applications. Suitable for light-duty machining; applicable to low-carbon steel, aluminum alloy, brass, cast iron, medium-carbon steel, stainless steel, acrylic, plastic, wood, etc. For machining thicker metals, low RPM + flood coolant ​is required. NOTE: Position the twist drill at 90° to the workpiece. For thick materials, drill in multiple passes to prevent overheating or breakage. For large holes, start with a guide hole. Use coolant to improve efficiency, extend tool life, and reduce material damage. INSTRUCTION: When machining different materials, the spindle speed and feed rate vary. Generally, the harder the material, the lower the spindle speed and feed rate should be. For specific speed and feed rate recommend for common materials, please refer to the details provided on the product page. √FEATURE:
The drill bit is made of 4341 high-speed steel material, it has high hardness and wear resistance, suitable for processing medium hardness materials
Gold finish can further enhance the drill bit's wear and corrosion resistance, thereby extending its service life.
The 135° split point tip drill provides excellent processing stability and is well-suited for harder materials. It effectively reduces the risk of cutting-edge chipping, thereby improving drilling efficiency and hole quality.
√APPLICATION:
The 4341 hss drills are suitable for light-duty machining; applicable to low-carbon steel, aluminum alloy, brass, cast iron, medium-carbon steel, stainless steel, acrylic, plastic, wood, etc. For machining thicker metals, low RPM + flood coolant​are required.

√PACKING LIST:
-Cutting Edge Diameter: #21 (4.039mm)
-Shank Diameter: #21
-Flute Length: 55mm/2.17 inch
-Total Length: 83mm/3.27 inch
-Package Content: 5pcs x Drill Bit

√NOTE:
When machining different materials, the spindle speed and feed rate vary.
Generally, the harder the material, the lower the spindle speed and feed rate need to be.
Position the twist drill at 90° to the workpiece.
For thick materials, drill in multiple passes to prevent overheating or breakage.
For large holes, start with a guide hole.
Use coolant to improve efficiency, extend tool life, and reduce material damage.
For specific speed and feed rates recommended for common materials, please refer to the details provided on the product page.