Heavyweight – Something We Love!
Modern industry demands increasingly advanced metalworking technologies. One of them is deep hole drilling in steel – a process that allows creating long, narrow, and precise holes with a depth exceeding 10 times the tool diameter.
This technology is applied wherever accuracy, repeatability, and high surface quality are essential.
What is Deep Hole Drilling?
Deep hole drilling is a mechanical process that produces holes of great depth while maintaining exceptional axial accuracy. 
Unlike traditional drilling, which produces relatively shallow holes, deep hole drilling uses specialized tools and machines capable of reaching lengths of up to 1600 mm.
How Does Deep Hole Drilling in Steel Work?
The process is performed using high-pressure coolant systems and specialized gun drills, which allow simultaneous chip removal and coolant flow.
The main steps include:
- Material preparation – the steel is securely clamped and centered to ensure stability.
- Tool selection – the gun drill is chosen according to diameter and material type.
- Drilling – the tool penetrates the steel at a controlled feed rate while the coolant removes chips.
- Cooling and lubrication – prevents material overheating.
- Hole finishing – optional honing or surface grinding.
Key Stages of Deep Hole Drilling
- Preparation and stabilization of the workpiece – ensures axial alignment.
- Process parameter control – CNC systems monitor speed and coolant pressure.
- Surface finishing – the final stage ensures smoothness and precision of the hole.
These steps allow achieving tolerances of ±0.05 mm, which is crucial for producing molds, bushings, or hydraulic plates. 
Gun Drill – The Heart of Deep Hole Drilling Technology
What is a Gun Drill?
A gun drill is a specialized tool with a long, slender body, equipped with a central coolant channel and a side chip removal channel.
It maintains the straightness of the hole even at depths of several hundred millimeters.
Its design allows drilling at high speeds without axial deviation.
Machines for Deep Hole Drilling – Precision in Every Detail
The process uses specialized CNC machining centers equipped with coolant systems and automatic parameter control.
At Akrostal, we use machines capable of:
- Drilling diameters: 3–30 mm,
- Maximum depth: 1600 mm,
- High repeatability and dimensional accuracy.
Deep Hole Drilling Service – Scope and Capabilities
Deep hole drilling service provided by Akrostal includes drilling in:
- structural steel, tool steel, and stainless steel,
- aluminum, brass, and bronze,
- injection molds, cooling plates, and bushings.
The service is carried out according to client documentation, with the possibility of full CAD-CAM design and turnkey machining.
Applications of Deep Hole Drilling in Industry
Deep hole drilling technology is used in multiple industries:
- injection molds and tool shops,
- industrial hydraulics and pneumatics,
- energy and automotive,
- aerospace and defense – where precision and surface smoothness are essential.
Advantages of CNC Deep Hole Drilling
- Precise, axial holes,
- High surface quality (Ra < 1.6 µm),
- Reduced tool wear due to internal cooling,
- Short lead times and high repeatability.
Common Issues and How to Avoid Them
During deep hole drilling, the following may occur:
- Tool seizure – avoided by effective cooling,
- Axial deviation – eliminated by precise centering,
- Vibrations and drill breakage – controlled through proper feed rate and rotational speed.
Regular process control and proper gun drill selection guarantee the highest hole quality.
How to Choose a Deep Hole Drilling Service Provider?
When choosing a company, pay attention to:
- Technical experience – years of metalworking practice.
- Machine park – modern CNC centers and precision equipment.
- Accuracy and quality certifications.
- On-time delivery and technical consultancy.
Why Choose Akrostal?
Akrostal specializes in deep hole drilling of steel and non-ferrous metals.
With modern machines, cooling systems, and a team of experienced operators, we provide the highest quality, accuracy, and short lead times.
Every order is handled individually according to client documentation.
FAQ – Frequently Asked Questions About Deep Hole Drilling
What is deep hole drilling?
A process of drilling holes deeper than 10 times the tool diameter while maintaining high accuracy.
What are the maximum drilling parameters at Akrostal?
Hole diameter: 3–30 mm, depth: up to 1600 mm.
How does a gun drill differ from a regular drill?
It has a special coolant channel and a design ensuring axial stability during deep hole drilling.
Does Akrostal handle custom projects?
Yes, we drill according to client technical documentation or design parts from scratch.
How long does the service take?
Timing depends on project complexity, but with efficient CNC machines, we offer very competitive lead times.
We invite you to cooperate and contact us, the Akrostal team.