Introduction

Gun Drill Bits are advanced tools specifically designed for drilling deep holes in metalworking applications. Their specialized design allows them to effectively drill holes up to 10 times their diameter, or even deeper. Choosing the right gun drill bits is essential for ensuring high processing quality, maximizing efficiency, and maintaining cost control. This article will comprehensively introduce the key factors in selecting gun drill bits to help you make an informed decision.

1. Understand the basic structure of gun drills

Gun drills are significantly different from traditional twist drills. Their main features include:

• Single cutting edge design: Most gun drills use a single-edge structure to reduce cutting force

• Internal cooling channel: allows high-pressure coolant to reach the cutting area directly

• Guide strip: provides support and guidance to ensure drilling straightness

• V-shaped chip groove: effectively guides chip discharge

2. Key parameters for selecting gun drills

1. Diameter selection

• The standard diameter range is usually 1.5 mm- 35 mm

• Consider the final size requirements of the workpiece and reserve possible finishing allowances

• The diameter tolerance is usually ±0.02mm to ±0.05mm

2. Length selection

• Ensure that the drill length is sufficient to complete the entire hole depth

• Generally divided into standard length and extended type

• Consider the stroke limitations of the machine tool

3. Material selection

• High-speed steel (HSS): economical and suitable for general steel

• Carbide: good wear resistance, suitable for high-hardness materials and mass production

• Coating type: TiN, TiAlN and other coatings can significantly extend the tool life

3. Choose according to the processing material

Different materials require different drill geometry parameters and coatings:

4. Cooling system considerations

Deep hole drilling is highly dependent on effective cooling:

• High-pressure cooling system: usually requires a pressure of 7-20MPa

• Coolant type: oil-based or water-soluble coolant

• Flow rate requirement: calculated according to the hole diameter, generally 0.5-1L/min is required for each millimeter of diameter

5. Machine tool requirements

Make sure your machine tool meets the requirements of deep hole drilling:

• Sufficient rigidity and stability

• High-pressure cooling system

• Appropriate speed and feed control capabilities

• Good guide support device

6. Brand and price considerations

Major brands on the market include:

• Imported brands: TBT, Botek, Deep Hole (higher price but stable quality)

• Domestic brands: cost-effective, suitable for projects with limited budgets

Price range reference (taking φ10mm as an example):

• Domestic high-speed steel: 200-500 yuan

• Imported carbide: 1500-4000 yuan

Conclusion

Choosing a suitable gun drill bit requires comprehensive consideration of processing materials, hole depth requirements, machine tool conditions and budget. Investing in high-quality gun drill bits and using them correctly can significantly improve machining efficiency and quality and reduce unit costs. For critical applications, it is recommended to consult a professional tool supplier or engineer for customized advice.