The characteristics of deep hole machining and the measures that should be taken in the machining process are as follows:

Deep hole machining, also known as gun drilling, is a specialized machining process used to create holes with a high aspect ratio (length-to-diameter ratio). These holes are typically characterized by their depth, often exceeding 10 times their diameter. In this description, I will provide an overview of the characteristics of deep hole machining and discuss the measures that should be taken in the machining process.

Characteristics of Deep Hole Machining:

1. High Aspect Ratio: The primary characteristic of deep hole machining is the high aspect ratio of the holes. These holes can be several meters deep while maintaining a relatively small diameter.

2. Precision Requirements: Deep hole machining often involves tight tolerances and high precision. Any deviation in the hole's dimensions or surface finish can be problematic, especially in applications like aerospace and medical devices.

3. Chip Evacuation: Efficient chip evacuation is crucial in deep hole drilling. As the hole gets deeper, chips can quickly accumulate and lead to tool damage or poor surface finish. Proper chip evacuation mechanisms are essential.

4. Coolant and Lubrication: Due to the extended machining time and high friction generated, adequate cooling and lubrication are critical. It helps in dissipating heat, prolonging tool life, and maintaining dimensional accuracy.

5. Tool Wear: Deep hole machining exerts significant wear on cutting tools due to the long cutting path. Specialized tool materials and coatings are often used to mitigate tool wear.

6. Vibration and Flexibility: As the drill extends deep into the workpiece, it can encounter issues related to vibration and tool deflection. Proper rigidity and support systems are needed to counteract these challenges.

Measures in Deep Hole Machining:

1. Specialized Tools: Use specialized deep hole drilling tools designed for this purpose. These tools often have internal coolant channels and coatings to enhance their performance and longevity.

2. High-Pressure Coolant: Employ high-pressure coolant systems to effectively remove chips and dissipate heat. This prevents chip clogging and tool damage.

3. Peck Drilling: In deep hole drilling, it's common to use a peck drilling technique, where the tool is intermittently withdrawn to break and clear chips. This improves chip evacuation and reduces the risk of tool breakage.

4. Workpiece Support: Adequate workpiece support is crucial to minimize vibration and tool deflection. Tailor the setup to the specific requirements of the job.

5. Quality Control: Implement stringent quality control measures to ensure that the dimensions and surface finish of the deep hole meet the required specifications. This may involve in-process inspections and post-machining measurements.

6. Tool Monitoring: Utilize tool monitoring systems that can detect tool wear or tool breakage in real-time. This helps prevent machining defects and tool-related issues.

7. Process Optimization: Continuously optimize the machining process parameters, such as cutting speed, feed rate, and coolant flow, to achieve the best results while maintaining tool integrity.

8. Training and Expertise: Ensure that operators and machinists are well-trained and experienced in deep hole machining techniques. This helps in preventing errors and achieving consistent results.

In conclusion, deep hole machining is a specialized process with unique characteristics and challenges. By using specialized tools, effective coolant systems, and proper machining techniques, manufacturers can produce deep holes with the required precision and quality. Additionally, a focus on continuous improvement and quality control is essential to excel in this demanding machining field.