Full manufacturing process of granite components

The manufacturing of precision granite components (platforms, bases, guides, gantries a precision process chain from raw blocks to micrometer-level finished products, with the core being stability, stress relief, step-by-step precision machining, and strict inspection. The followingaks down the complete process and marks Critical Control Points (CCP).

I. Raw Material Preparation (Source Determines Stability)

1. Ore Source and Material Selection (CCP0)
   Prefe stones: Jinan Green, Zhangqiu Black, Fujian Green, Indian Black Sandalwood (fine, uniform grain, no layering, low expansion).
   Physical properties
   Density ≥ 2.6 g/cm³
   Compressive strength ≥ 80 MPa
   Thermal expansion coefficient (2.5–5)×10⁻⁶ ℃
   No cracks, color lines, holes, or impurities.
   Grade: Precision parts must use Grade A / Grade 00 material.
2. Raw Block Initial Inspection and Pre-treal inspection flaw detection (ultrasonic) to reject defective material.
   Raw block cutting: Cut into rough plates/rough blanks using diamond gang saws / wire saw, leaving a 2–3 mm machining allowance.

II. Rough Forming (Removing Large Allowances, Establishing Benchmarks)

1. Sawing and Shaping
   Frame saw / ided cutting machine for slicing → CNC wire saw / water jet for shaping.
   Allowance: 2 mm for length/width, 3 mm for thickness.
2. Rough Grindf Benchmarks (CCP1)
   Gantry thicknessing machine rough grinds six sides to establish reference planes.
   Flatness control: ≤ 0.2 mm/m.
   PurposeTo provide a stable reference for subsequent aging and precision grinding.

III. Stress Relief and Aging (Most Critical, Most Easily Overlooked)

1. Natural Aging (Preferred)
   Place r / constant temperature workshop for 7–15 days (months for large pieces) to release internal stresses from cutting and rough grinding.
2. Thermal Aging (Accel
   80°C curing chamber for 24 h → deep freeze at -10°C for 4 h, cycle 1–2 times.
   Purpose: To completely eliminate internal stresses and preventation during subsequent machining / use.
3. Constant Temperature Stabilization
   After aging, stabilize in a 20±1°C, 50%±5% humidity envonment for ≥ 24 h to stabilize dimensions.

IV. Precision Machining (Micrometer-Level Forming)

1. Semi-precision Grinding / Precision Grinding (ry precision grinding machine, diamond grinding wheels for step-by-step grinding:
   Rough grinding → Semi-precision grinding → Precision grinding
   Flatness gradually improvedto ≤ 5–10 μm/m.
   Sides, perpendicularity, and parallelism processed simultaneously.
2. Drilling / Slotting / Tapping (CCP3)
   CNC drilling machine / machning center, diamond drill bits.
   Hole position accuracy ±0.01 mm, perpendicularity ≤ 0.005 mm/100 mm.
   Strictly prohibited torily enlarge or modify holes later.
3. Cleaning and Chamfering
   High-pressure water / air cleaning to remove dust and debris.
   Blunting sharp eges (C0.5–C2) to prevent chipping and scratching.

V. Ultra-precision Grinding (Final Precision)

1. Plane Ultra-precision Grinding (CCP4)
   Precision grinding mach, resin-bonded diamond grinding discs, processed step-by-step from 600# to 2000# grit.
   Flatness: Gre 00 ≤ 2–5 μm/m; Grade 000 ≤ 1–2 μm/m.
   Surface roughness: Ra ≤ 0.1 μm (mirror finish).
2. Side and Geometric Precision Refinement
   5-axis side grinding / grinding to ensure final perpendicularity, parallelism, and hole position accuracy.

VI.and Assembly (If Required)

1. Insert Preparation
   Stainless steel / copper bushings / threaded inserts, machined according to drawings.
2. Constant Temperature Assembly
   Component andrts are kept at a constant temperature of 20±1°C for 8–12 h.
   Press fitting / bonding (epoxy adhesive), ensuring interference fit and perpendcularity.
3. Secondary Precision Grinding
   Local precision grinding after inserts, ensuring

VII. Cleaning, Sealing, and Protection

1. Deep Cleaning
   Ultrasonic cleaning → Pure water rinse → Dust-fee drying.
2. Sealing Treatment (Clean Room / Anti-contamination)
   Dense, non-porous material is optional; porous material must undergo epoxy resin sealing to prevent moisture absorption and conamination.
3. Rust Prevention / Protection
   Apply rust preventive oil to non-working surfaces; apply protective film to working surfaces.

VIII. Full-Size Inspection (CCP5, M for Factory Release)

1. Core Precision Inspection
   Flatness: Laser plane interferometer, electronic level.
   Perpendicularity / Parallelism: Autocollimator, marble right an.
   Dimensions / Hole Positioning: Coordinate Measuring Machine (CMM).
   Roughness: Surface roughness meter (Ra).
2. Appearance and Performance
   No cracks,no chipping, no scratches.
   Density and water absorption rate spot checks.
3. Report Issuance
   Attach precision inspection report (flatness, perpendicularity, hole positioning, rouhness).

IX. Packaging and Shipping
Wooden crate / Aluminum case shock-absorbing foam, fixed with three-point support (to prevent deformation during transportation).
Moisture-proof and colproof labels.

Summary of Key Control Points (CCP) Throughout the Process
Raw Material Selection: Grade A / Grade 00, defect-free.
Rough Grinding Benchma: Flatness ≤ 0.2 mm/m.
Aging Treatment: Natural / Thermal aging, complete stress relief.
Precision Grinding / Super Precision Grinding: Gradually improved to Grade precision.
Drilling Precision: Hole position ±0.01 mm, perpendicularity ≤ 0.005 mm/100 mm.
Final Inspection: Full-sze and full-precision qualification required for factory release.

One-sentence Summary:
Precision granite components = Good material Thorough stress relief Step-by-step precision grinding Strict inspection; nof these can be missing.