Boasting high stability and low deformation, granite machine tool beds serve as core reference components for ultra‑precision equipment. Nevertheless, stone material features brittleness. Finished beds have undergone high‑precision grinding, so working surfaces, positioning edges and areas around mounting screw holes are vulnerable zones. Many accuracy defects of granite beds do not originate from manufacturers, but arise from knocks and impacts during transit, hoisting, positioning and commissioning. These may lead to edge chipping, corner breakage and hidden internal cracks. Some internal injuries are invisible to naked eyes. After equipment is put into service, cracks expand gradually under continuous loads, damaging the flat reference of beds and triggering abnormal equipment accuracy. Based on practical project experience, ZHHIMG sorts out anti‑collision protection points for granite beds throughout handling and installation, avoiding man‑made product damage after delivery and ensuring long‑term equipment precision.
Hoisting is the highest‑risk procedure for collision. It is not recommended to bind steel wire ropes directly to granite beds. Hard steel wire ropes may scratch side edges and precision‑machined surfaces when swinging during lifting. Wide flexible lifting slings are preferred for hoisting. Thickened rubber pads shall be placed at sling contact positions for isolation, keeping away from T‑slots, threaded holes and precision reference surfaces. Lifting points must be arranged strictly in accordance with marked positions on products. Random selection of corners as lifting points is forbidden to prevent local stress cracking caused by uneven force. Before hoisting large‑size granite beds, tooling, supports and protruding components on lifting paths shall be cleared. Swing range shall be predicted to avoid scraping and collision between beds, walls and equipment frames during hoisting. Operators shall control lifting and lowering speed. Sudden lifting or dropping is prohibited. No personnel shall stand beneath beds to prevent dual risks of safety hazards and product damage from accidental falling.
Short‑distance transfer also requires sufficient attention. For in‑plant short‑distance moving, granite beds shall never be dragged directly on the ground. Dragging friction will scratch bottom supporting areas and produce impact stress that causes invisible internal damage. Air‑cushion transport devices or special rigid transport brackets are recommended. Buffer pads shall be fully laid under beds to ensure uniform force. Sudden stops and sharp turns shall be minimized during transfer to prevent beds from sliding and shifting on brackets. When passing through factory gates and channel corners, overall dimensions and turning radii shall be calculated in advance with sufficient clearance reserved, so as to avoid edges scraping door frames and columns. For outbound shipment, high‑density buffer materials shall be filled inside wooden cases. Protective boards shall cover precision‑machined surfaces. Beds shall be limited and fixed around to prevent shifting and striking against cases due to jolting in transit.
Positioning is an easily‑overlooked risk point. Granite beds must not be dropped hard onto the ground. Jacks or adjustable leveling wedges shall be adopted for slow lowering onto supporting bases. Staff shall observe each contact point during lowering to realize simultaneous force bearing and avoid forced pressure on single points. It is forbidden to push precision‑machined surfaces directly with crowbars for position adjustment. If fine‑tuning is needed, force shall be applied on non‑machined rough side surfaces. Precision‑machined working surfaces shall be covered with dust‑proof and anti‑impact protective boards throughout positioning, preventing dents and chipping caused by accidental falling of tools, fasteners and hardware parts. Once local impact occurs, visual inspection alone cannot confirm qualification. Metrological tools shall be used to re‑check flatness and rule out hidden invisible micro‑cracks.
Specifications shall also be followed for protection during on‑site assembly. After beds are positioned, tools shall be kept away from precision‑machined zones when mounting guide rails, modules and other components. Falling hard parts such as wrenches and bolts may create pits and chipping on stone surfaces. Rubber protective mats are suggested for assembly areas. Tighten bolts in compliance with specified torque values. Excessive‑torque forced tightening is forbidden, as over‑stress at screw holes may cause cracking around hole openings. Isolation protection shall be implemented when metal workpieces and modules are hoisted above beds during assembly to prevent workpiece falling impact. Accessories and materials shall never be stacked directly on bed reference surfaces.
Protection does not end after installation. On‑site management shall be maintained in equipment commissioning phase. Isolation barriers shall be arranged for cross‑operations of other subsequent working types to protect beds from welding spatter, tool knocks and falling materials. If cutting or grinding work is carried out around beds, granite surfaces must be covered to avoid burns from high‑temperature sparks. Special protective covers shall be kept on‑site to shield high‑precision working surfaces in non‑operating status. 
Although manufacturers can guarantee raw‑material quality, machining accuracy and factory inspection of granite beds, handling, hoisting and installation take place at customer sites. Any missing protection measure may result in irreversible damage. ZHHIMG provides handling and installation guidelines together with product delivery. Drawing on rich experience in ultra‑precision components, the company reminds customers of field protection for brittle stone parts. With complete ISO triple‑system certifications, CE certification and full‑set metrological inspection capabilities, ZHHIMG guarantees product quality from blank screening and precision machining to delivery guidance.
Failure analysis shows that accuracy failure of granite beds is not entirely attributed to material or processing defects. Quite a number of problems stem from hidden collision damage during handling and installation. For high‑value precision equipment, besides focusing on product accuracy indicators, standardized implementation of anti‑collision measures in handling and installation enables granite beds to fully exert material performance and deliver stable and reliable precision references for complete machines.
Post time: Sep-03-2026