Broaching is a machining process that enables the production of moulded internal profiles in an existing bore. It is distinguished by its high precision, repeatability, and speed of execution, making it particularly suitable for applications in precision engineering, automotive, aerospace, and manufacturing. Thanks to the use of CNC lathes and automated machining centres, this technique ensures consistent results, reduces production time, and improves the final quality of machined components.

 

The broach, combined with the broaching tool, allows for controlled material removal until the desired shape is achieved. The broach is characterised by a progressive tooth sequence that shapes the internal bore with extreme precision, ensuring perfect mechanical fit. This system guarantees maximum stability and functionality of assembled components, particularly shafts and polygonal couplings.

Broaches for internal profiles are used in advanced machining, especially in gears, shafts, and other critical components. Their use on CNC lathes ensures consistent performance and dimensional repeatability, even in high-speed machining. These tools are valued for their reliability, wear resistance, and versatility, making them essential for optimising industrial production.

 

The most commonly used internal profiles in broaching include:
Square profile, suitable for housing bars, handles, and levers with square shanks.
Hexagonal profile, used to create recessed hexagons on threaded pins, valves, and threaded inserts, compatible with Allen keys.
Torx profile, widely used in automotive, medical, and aerospace industries, applied to screws, inserts, and valves. Thanks to this shape, components can be assembled and disassembled using Torx spanners.

 

The broach is a rotating device mounted on automatic and CNC lathes. It consists of a fixed part, clamped in the machine fixture, and a rotating part on which the broach is mounted. This combination enables precise machining, minimising tolerance errors.

 

The broach operates through material removal by compression. The forces involved are high, so the system is designed to minimise the required pressure. When the broach comes into contact with the workpiece, it oscillates around its axis, gradually removing material. This movement generates a variable contact point, evenly distributing the stress along the bore circumference.

By repeating this process over multiple passes, the profile is shaped to the desired length. This method ensures precise and repeatable results, guaranteeing perfectly formed components.

 

Broaching is an essential technology for creating complex internal profiles, offering significant advantages in precision, repeatability, and productivity. The use of CNC lathes and machining centres optimises processing, reduces production time, and enhances component quality. Thanks to its reliability and versatility, the broach is a fundamental solution for industries requiring high-quality standards and mechanical performance.