In fields such as optical inspection, wafer metrology and high-precision CMM measurement, subtle magnetic field disturbances inside equipment often become hidden factors undermining accuracy. Many precision inspection devices are equipped with grating sensors, photoelectric detectors, magnetic scales and various highly sensitive optical components. Even an extremely weak magnetic field can cause signal shift and image distortion, eventually leading to distorted inspection data. In the past, cast iron and steel were widely adopted for equipment bases in the industry. Such metallic materials are inherently magnetic and tend to retain residual magnetism after machining and assembly. Extra demagnetization procedures are therefore required, which not only raise costs but also see demagnetization effects degrade during equipment operation. Featuring natural non-magnetic properties, UNPARALLELED® granite mechanical parts fundamentally eliminate magnetization interference and suit the application demands of various high-sensitivity precision inspection equipment.
Granite is a natural silicate crystalline mineral with no magnetizable metallic phases inside. Whether during grinding, insert embedding or long-term equipment operation, the stone substrate itself cannot be magnetized and will not retain residual magnetism. Unlike steel and cast iron, granite will not induce magnetic fields under the effect of surrounding electromagnetic components such as motors and coils, and will not interfere with signal acquisition by sensing units inside equipment. In semiconductor wafer defect inspection, micro-nano topography measurement and optical imaging inspection scenarios, sensors are extremely sensitive to magnetic fields. The non-magnetic substrate ensures clean and stable measurement signals, reduces false positives and missed detections, and stabilizes product yield.
A common question arises: will embedded metal inserts in granite components introduce magnetic interference? During the integrated insert machining process, UNPARALLELED® selects non-magnetic materials such as non-magnetic stainless steel for embedded inserts according to the electromagnetic environment requirements of equipment. The complete granite assembly achieves non-magnetic performance for both substrate and embedded structures. Metal inserts only undertake mechanical connection and load-bearing functions without generating extra magnetic fields. The inherent non-magnetic advantage of the granite substrate is fully preserved, and the electromagnetic environment of the whole machine will not be compromised by assembly structures.
Apart from non-magnetic characteristics, this material advantage works synergistically with other inherent properties of granite. Precision inspection equipment usually requires continuous long-duration scanning. Vibration generated by start-stop motion mechanisms and workshop temperature fluctuations will affect inspection results. With a low expansion coefficient and excellent damping performance, granite suppresses micro-vibration and thermal deformation while isolating magnetic interference, keeping optical and inspection modules steadily positioned on the reference platform. A single material satisfies multiple demands including non-magnetism, vibration reduction and dimensional stability. It simplifies the electromagnetic shielding design of the whole machine and removes many extra magnetic protection and demagnetization supporting structures.
For equipment manufacturing and delivery, non-magnetic granite components also simplify quality inspection workflows. Metal bases need repeated residual magnetism testing with professional instruments. Rework and demagnetization will be required once values exceed standards, prolonging the production cycle. UNPARALLELED® granite mechanical parts require no demagnetization treatment before delivery; only geometric accuracy inspection is needed. One special electromagnetic performance inspection procedure is omitted, shortening the overall development cycle for equipment manufacturers. Meanwhile, the surface of non-magnetic granite hardly attracts metallic micro-particles, lowering contamination risks from adsorbed metal debris in dust-free inspection workshops and meeting both electromagnetic compatibility and cleanliness requirements.
It should be noted that non-magnetic does not mean complete isolation from strong external magnetic fields. If there are intense external magnetic sources around the equipment, corresponding electromagnetic shielding design is still necessary. The value of granite components lies in eliminating magnetization interference originating from the base itself and removing the primary internal magnetic source of the equipment, rather than fully blocking penetration of strong external magnetic fields. As long as the electromagnetic layout of the whole machine is properly designed, non-magnetic granite reference parts can give full play to their advantages.
Magnetic interference is a non-negligible factor for precision inspection equipment. With natural non-magnetic and non-magnetizable material properties, UNPARALLELED® granite mechanical parts eliminate internal magnetic fields generated by the base, protecting photoelectric and magnetic-sensing precision inspection components from magnetization interference and reducing signal distortion and misjudgment in detection. Combined with high dimensional stability and vibration damping performance, such components can well satisfy strict specifications of optical metrology, semiconductor inspection and high-precision metrology equipment, delivering a clean and stable reference load-bearing solution for precision inspection systems.