Application Range

·Processing diameter range: 12D-50D ·Effective drilling depth: 400mm

Application Cases

	Workpiece: crankshaft              Hardness: HRC28-32 Workpiece material: 42CrMo   Drilling depth: 150mm Machine: vertical machining center  Drilling method: continuous machining
	Comparison test	Original inserts	Halnn inserts
	Diameter	D8 internal coolant  deep hole drill	D8 internal coolant  deep hole drill
	Vc(m/min)	62.8m/min	62.8m/min
	F(mm/min)	500mm/min	500mm/min
	n(r/min)	2500r/min	2500r/min
	Processed Quantity	180 pcs	220 pcs
	Results: Under the same processing parameters, the life of Halnn's insert increased by 22%.

A3 Steel (Q235) Processing with Halnn Deep Hole Drill

Material Overview

Q235, commonly known as A3 steel, is a widely used low-carbon structural steel with excellent plasticity, toughness, weldability, and cold stamping performance. It also 

possesses good strength and bending properties, making it suitable for general mechanical components and welded structures.

Customer Requirements & Workpiece Information

·Material: Stainless steel, steel parts (A3 steel)

·Machine Tool: Vertical machining center

·Drilling Method: Continuous drilling

·Workpiece Hardness: Below HB200

·Cooling Method: Coolant

Challenges in Machining Process

1. Chip Breaking Issues: The high plasticity and toughness of A3 steel lead to significant challenges in chip control, increasing the risk of tool breakage.

2. Deep Hole Drilling Complexity: The hole depth reaches 87mm with a diameter of only 2.9mm, resulting in an extreme length-to-diameter ratio of 40:1, making chip 

evacuation very difficult.

3. Manufacturing Difficulty: The small diameter and high aspect ratio pose significant challenges in tool manufacturing and machining stability.

Halnn Tool Design & Manufacturing Advantages

1. Optimized Chip Breaker & Rake Angle Design: A unique flute geometry and specialized core taper ensure smooth and efficient chip breaking and evacuation.

2. Special Drill Tip & Cutting Edge Design: The optimized point angle and positive rake angle at the chisel edge enhance centering accuracy, reduce cutting 

resistance, and promote the formation of easily breakable conical spiral chips, significantly improving chip control.

3. Large Flute Opening & Four-Flute Guide Design: Provides enhanced cutting stability and reduced cutting resistance, ensuring a smoother drilling process.

4. High-Feed Rate Design: Allows for significantly improved processing efficiency, reducing overall machining time.

5. Advanced Manufacturing Process: Utilizing imported machine tools with P-axis configuration and full-length tool support ensures the reliability and precision required

 for producing 40:1 aspect ratio deep-hole drills.

Final Test Results

	·Tool Specifications: D2.9mm Internal Coolant Deep Hole Drill
	·Drilling Depth: 87mm
	·Cutting Speed (Vc): 54.6 mm/min
	·Spindle Speed (n): 6000 rpm
	·Original Tool Life: 200 pieces
	·Halnn Drill Life: 280 pieces
	·Tool Life Increased by: 40%
	·Machining Efficiency Improved by: 38.8%
Halnn’s deep hole drilling solution successfully overcame the challenges associated with A3 steel machining, delivering enhanced tool life, improved processing efficiency, and stable performance. Our specialized design ensures reliable deep hole drilling in tough materials, making Halnn the ideal choice for challenging machining applications.