Writing Data: When data is written, the read heads generate a small magnetic field that changes the orientation of magnetic particles on the disk. Each magnetic particle represents a bit of information (0 or 1). Changing the orientation of particles in the direction of or against the disk's rotation represents these binary states. This process requires extreme precision, as the data density on modern disks is enormous.

Reading Data: When reading data, the read heads detect changes in the magnetic orientation on the disk surface. Magnetoresistive (MR) or giant magnetoresistive (GMR) technology in the heads respond to these changes, allowing the disk's electronics to convert these signals back into digital information that the computer can process.

Distance of Heads from Disk: The read heads move very close to the surface of the data platters of the disk, but must not touch them to avoid damage. This distance is often measured in nanometers, requiring precise engineering and manufacturing.

Magnetic Bit: When the read head writes a value of 0 or 1, it does so by changing the magnetic orientation in this small segment. Polarization can be positive or negative, representing either 0 or 1.

Read/Write Heads and Data Recovery from Hard Drives

The read heads of hard disk drives (HDDs) are often the cause of failure, especially after physical or mechanical damage, such as falls or strong impacts. Given their proximity to the data platters - measured in nanometers - even slight disturbances can cause significant damage. After a fall or impact, the read heads may either physically touch the platters, leading to mechanical damage, or they may shift from their optimal position, making data reading difficult or impossible.

Failure of the read heads can also be caused by their spontaneous wear or manufacturing defects. In such cases, problems such as sudden errors in reading or writing data or data loss without an apparent cause may occur.

In the process of data recovery from hard disk drives (HDDs), the diagnosis and repair, or replacement of the read heads is often key. Data recovery experts have the tools and techniques to replace damaged read heads and to precisely adjust new heads to safely and efficiently recover data. This process requires not only technical skills but also detailed knowledge of HDD construction and the principles of magnetic data recording.

Although modern technology allows for considerable success in data recovery, it's important to realize that physical damage to disks can in some cases lead to irreversible data loss. Therefore, it's important to protect hard drives from physical damage and also to regularly backup important data.