Key Process Points of Granite Machine Tool Body Forming

High-quality substrate is the foundation of precision forming and the key distinction from low-end industry products. ZHHIMG exclusively adopts high-density black granite and eliminates ordinary marble and inferior stone materials. We strictly select crack-free, sand-hole-free and uniform-texture premium raw blocks. With a density of 3100kg/m³, the selected granite features superior physical performance, extremely low expansion coefficient, high rigidity and minimal internal stress, outperforming ordinary European and American granite materials. Before warehousing, all raw materials undergo multiple flaw detection and physical performance tests to eliminate inherent material defects. This strict selection fundamentally guarantees structural stability and non-deformation of the machine tool body, laying a solid foundation for ultra-precision machining. All material parameters are fully traceable to ensure stable and reliable original quality.

Natural granite contains tiny inherent internal stress. Without thorough aging treatment, residual stress will be gradually released during processing and service, causing body warpage and precision drift — a common defect of low-cost manufacturers. Before formal processing, all granite blocks are placed in professional stockyards for long-term natural aging, combined with manual stress relief procedures to eliminate internal residual stress completely. For super-large and heavy-duty blanks, segmented static placement and repeated calibration are adopted to ensure uniform and thorough stress release. After aging treatment, dimensional recheck and flatness inspection are carried out to screen qualified blanks, effectively avoiding structural deformation in subsequent application.

Equipped with heavy-duty CNC machines and large traveling cranes, ZHHIMG supports integrated forming of super-large granite machine tool bodies with a single unit weight of 100 tons, a maximum length of 20m, width of 4000mm and thickness of 1000mm. Different from the industry’s conventional segmented splicing method that causes accumulated errors and joint gaps, our one-time clamping and integral forming technology effectively avoids repeated clamping errors and flatness deviation. In the rough machining stage, uniform grinding allowance is reserved to balance processing efficiency and precision requirements. In the semi-finishing stage, datum surfaces, mounting grooves, positioning holes and guide rail bases are precisely processed and calibrated to optimize overall flatness and structural consistency, preparing for ultra-precision grinding.

Precision grinding is the core procedure that determines final precision. ZHHIMG is equipped with four high-precision large grinding machines imported from Taiwan Nantong, each valued at over 500,000 USD, capable of grinding metal and non-metal workpieces up to 6000mm in length. The grinding process follows a progressive sequence from rough grinding, medium grinding to finish grinding to gradually eliminate tool marks and processing stress. With high-precision equipment and professional technical calibration, the flatness, straightness and parallelism of key body surfaces remain highly consistent, achieving stable micron-level precision and providing reliable benchmarks for subsequent assembly and calibration.

Temperature fluctuation, micro-vibration and dust contamination are the main causes of precision loss during finishing. All precision grinding and finishing processes are completed in our 10,000 ㎡ professional constant-temperature and constant-humidity workshop. The workshop adopts military-grade ultra-hard concrete floors with a thickness of more than 1000mm, equipped with 500mm-wide and 2000mm-deep annular vibration isolation trenches and silent cranes to completely isolate external vibration interference. Stable temperature and humidity eliminate dimensional deviation caused by thermal expansion and contraction. Meanwhile, the semiconductor-grade dust-free assembly workshop prevents surface precision damage caused by dust adhesion. The fully closed stable processing environment permanently locks the forming precision of granite bodies.

Mechanical grinding ensures standard high precision, while nano-level ultimate accuracy relies on superior manual craftsmanship. ZHHIMG’s senior polishing masters possess more than 30 years of professional lapping experience and are proficient in global mainstream metrology standards including German DIN, American ASME, Japanese JIS and Chinese GB standards. With micron-level sensitive tactile judgment, they can accurately control material removal and finely correct tiny mechanical processing errors, polishing key datum surfaces to nano-level flatness. Each machine tool body undergoes repeated manual lapping, calibration and re-inspection to eliminate blind-spot defects, achieving industry-leading flatness and fitting accuracy.

We adhere to the core manufacturing principle that “precision production is based on accurate measurement”. Every processing procedure is matched with strict inspection and verification. Our full set of high-end testing equipment includes German Mahr dial gauges, Mitutoyo precision measuring tools, Swiss WYLER electronic levels and British Renishaw laser interferometers. All measuring instruments hold valid calibration certificates issued by municipal and provincial metrology institutes, with measurement data traceable to national benchmark standards. After forming, key parameters including flatness, straightness, verticality, hole position accuracy and parallelism are fully inspected and verified in accordance with international standards to ensure qualified and stable product precision.

After finishing and inspection, all granite bodies are assembled in a professional dust-free workshop. Air-bearing components, positioning parts and mounting accessories are precisely installed with strictly controlled assembly gaps and fitting accuracy to avoid assembly stress and alignment deviation. All assembly procedures follow standardized operating specifications. After assembly, overall precision recheck and long-term stability simulation tests are conducted to ensure firm structure, constant precision and reliable long-term operation for high-end precision equipment.

ZHHIMG’s granite machine tool body forming technology features seven core advantages: strict material selection, thorough stress aging, integral machining, precise grinding, constant-temperature fine finishing, full-range inspection and dust-free assembly. Supported by advanced equipment, superior manual craftsmanship, international standards and strict quality control, our processes effectively solve common industry problems such as deformation, low precision, poor stability and short service life. Full-process standardized quality management enables our granite bodies to maintain ultra-high precision for long-term service, perfectly matching the application demands of semiconductors, laser precision processing, high-end metrology and other ultra-precision fields, establishing ZHHIMG as a benchmark enterprise in the global precision manufacturing industry.