Turret Punching: CNC Presses, Tooling, and Applications

CNC turret punching

Sheet metal punching is a key method used in metal fabrication to create holes of various shapes and sizes. The fundamental concept is striking the punch having an identical profile to the desired hole geometry on the metal sheet against the matching dies. 

Need holes or slots manufactured to your drawing? Review our sheet metal punching services, then request a quote with the material, thickness and quantity.

There are different equipment and techniques of punching, turret punching is one of them. Unlike manual or conventional CNC Die punching, it accommodates multiple tooling stations in a single setup for high-speed production, complex part geometries, and efficient nesting on large sheets.

This article will cover how a CNC turret punching works, its benefits & industrial applications, and much more.

What is Turret Punching? 

Turret punching process

Turret punching uses a CNC-controlled press and an indexed selection of punch-and-die tools to create holes or slots. Its practicality depends on the pattern, material, tool availability and required edge and flatness conditions.

Many turret punch presses use upper and lower indexing turrets holding matched punches and dies. Station number, tool size and indexing capability are machine-specific.

The turret rotates and positions the worksheet between the desired punch tooling and die. Then, the punch strikes the sheet, quickly moves upward, and repeats the process, while the sheet moves to the next position for subsequent sheet metal hole punching operations. 

Turret punching can produce round, rectangular and other tool-defined openings. Installed tools and compatible stations govern the available shapes; automatic indexing does not eliminate tool selection or tool changes.

Structure and Components of CNC Turret Punch Press 

Turret punch press components

CNC turret punch presses are known for their compact designs and rigid structures. Different systems and components work together to punch accurate and repeatable holes in metal sheets. 

Let’s further elaborate on the structure through the different components of the CNC turret punch press. 

Turret Tooling System

Turret tooling 

Turret punching presses are named after their unique tooling system, called turret tooling. It contains upper and lower sections, equipped with various punches and corresponding dies. You can find them above the working bed of the punching press. 

The upper turret section can move along the rotational direction to switch the punching tool, whereas the metal sheet moves along the X and Y axes between the upper and lower turrets. These motions are controlled by CNC instructions. 

Sheet Clamp

This component holds the metal sheet and keeps it in its determined place. It is essential to precisely position and align the sheet with the tooling while striking.  

Punch Striker 

Striker is positioned above the punch and moves down, facilitating the striking of the punch to the metal sheet. So, the sheet metal turret punch can shear-cut the material. Hydraulic, mechanical, or servo motors are used to power the striker. 

Turret Key 

Turret keys are responsible for holding the angular tools in the rotational direction, ensuring correct alignment for punching. As the turret rotates, they maintain the angular position of the tools. 

Lifters 

Punch springs or lifting mechanisms return the punch after a stroke; stripping separates the sheet from the tool. Tool construction varies by system.

Punching Dies 

Dies are the precision engineering tools that help counterpart punches to shear the material against their cutting edges. These are typically made with tool steel, carbide, or other tough materials. In turret punching presses, they are mounted on the lower part of the turret tooling system.  

Working Bed/Table 

It is a flat bed that provides space to feed the sheet and carry out the punching operations. A work bed/table is typically made with hardened steel and helps to support and position the sheet for operations. 

Working of CNC Turret Punching Machine

The working of CNC turret punching is similar to the standard sheet metal punching process, except for the die-punch tooling setup. Different punch profiles and matching are mounted on the upper and lower parts of turret systems. The turret can rotate and apply specific punches to create desired holes in various locations of a metal sheet. 

Working of the turret punch press

Here is the working mechanism of CNC turret punching: 

1. The CNC system interprets the instructions from G & M codes about punching sequence, movement path, and punch selection. 
2. The servo system moves the worksheet along the X & Y axes for its precise position between the punch and die. 
3. The turret indexes the selected punch and matching die into the working position. Tool-angle indexing is available only where the machine and tool station support it.
4. The pressing mechanism (servo, hydraulic, etc.) drives the ram and strikes the punch to the sheet metal against the die.
5. The programmed sequence positions the sheet and performs strokes for individual holes or overlapping nibbling cuts. Feed and stroke coordination depend on the machine and operation.

What Are the Different Types of CNC Punching Machines? 

Types of punch presses

Based on the driving mechanism used in metal punching methods,  punching machines can be classified into three different types: mechanical, hydraulic, and servo press machines. 

CNC Mechanical Press

A mechanical CNC punch press relies on a flywheel & cranks, which store and convert the rotational forces into vertical forces for pressing and punching the sheet. You can choose a mechanical press for simple and repetitive work that requires continuous high-speed operation.

CNC Hydraulic Press

Hydraulic Presses

In hydraulic presses, fluid motion drives the piston in a vertical direction to deliver the punching force. As they require frequent changes of hydraulic oil and other maintenance, they might be less suitable for use in large sheets and high-temperature conditions. 

CNC Electrical-Servo Press

Servo-electric punch presses use electrically driven mechanisms to generate the punching stroke. Drive arrangements, stroke control and forming options depend on the machine design.

Advantages of CNC Turret Punching 

Using a sheet metal turret punch for custom holes and sheet metal punching offers benefits such as high fabrication speed, accuracy, repeatability, and tooling flexibility.  

Let’s look at the list of advantages offered by sheet metal punching services. 

• High Fabrication Speed: With automatic tool changeovers and minimal machine downtime, turret punching enables a high fabrication speed. 
• Dimensional control: Hole size, position and repeatability depend on machine, tool guidance, material, wear and the agreed inspection conditions.
• Complex Shapes: The interchangeable tooling allows for the creation of versatile shapes, including holes and other features, in a single setup. 
• Repeatability:  The CNC automation and turret tooling result in high repeatability of sheet metal parts. 
• Cost-Effective: The high production speed, reduced labor cost, and lower material wastage make turret punching a cost-effective fabrication process. 

Is Turret Punching Expensive? 

Turret punching cost

Turret punching can be economical for repeated patterns when suitable tools are available. Setup, special tooling, hit count, material yield, deburring and final processing determine the cost. Tool life depends on material, geometry, maintenance and operating conditions.

The exact cost of turret punching depends on factors such as hole density, design complexity, material type, sheet thickness, production volume, and post-processing requirements.

To determine the cost of your punching project, simply upload your design and get a quote from us.

Industrial Applications of Turret Punching 

Turret Punching Applications

The turret punching applications are widespread across the industries, including general hardware & furniture, electronic & electrical, household appliances, automotive, medical equipment, and HVAC.

The table below outlines common applications with examples of punch press products.

Read More: 

• Punching Vs Blanking
• punching vs stamping

Do you Need Metal Punching and Stamping Parts? Contact ProleanTech

For purchased panels, brackets or enclosure plates, review our sheet metal punching services. Send the drawing and acceptance requirements for a project-specific manufacturing route.

For your part, ProleanTech reviews the required holes, material, thickness, quantity and secondary operations. CNC turret punching, nibbling, louvers and other special features require explicit confirmation in the quotation; this guide is not an equipment ownership list.

Summing Up 

As we have discussed, turret punching is an efficient, cost-effective, and precise method for creating holes in sheet metal parts. You can use this method combined with bending, stamping, or other forming processes to achieve higher complexity. However, it is essential to utilize the appropriate type of punching presses and tooling to leverage the full capabilities. 

If you are still confused about turret punching and stamping strategies, contact us. Our engineers will provide the detailed consultation you need before starting the project. 

FAQs

What is a punch press? 

It is a sheet metal forming mechanism that cuts or shapes the sheet metal using the die and punches in pairs. Punches strike the sheet with a high force and its edges into a matching die. 

What is the difference between a turret punch machine and a laser cutting machine? 

The primary difference lies in their working mechanisms: a turret punch machine utilizes high-force punches and dies to cut or form sheet metal, whereas a laser cutter uses a concentrated laser beam that melts and vaporizes the material to create cuts and shapes. 

What is a turret punch?

A turret punch holds several matched punch-and-die sets in indexed stations. It can select installed tools automatically, but non-installed shapes or incompatible tools require changes or a different route.