Quartz glass tube

Buyers must distinguish between Fused Quartz (natural sand) and Synthetic Fused Silica. For high-end semiconductor or optical applications, Synthetic Fused Silica is required due to its ultra-high purity (99.999%+) and low hydroxyl (OH) content. For general industrial heating or lighting, JGS1, JGS2, or JGS3 standards are common. Key technical parameters include thermal shock resistance (up to 1100°C), linear expansion coefficient (5.5 × 10⁻⁷/°C), and optical transmittance (>90% in UV/Visible range).

Precision is critical for integration into machinery. You should specify Outer Diameter (OD) and Wall Thickness (WT) tolerances, typically requiring ±0.1mm to ±0.5mm depending on the tube size. For specialized applications, request ovality (out-of-roundness) limits and straightness benchmarks (usually <0.3% of total length). Always ask the supplier if they use automatic laser diameter measurement systems during production to ensure consistency across bulk batches.

Ensure the supplier adheres to ISO 9001 for quality management. For laboratory or medical use, RoHS and REACH compliance are mandatory to ensure the absence of heavy metals. If the tubes are used in food processing or water sterilization (UV lamps), verify FDA or NSF certifications. On Made-in-China.com, look for Audited Suppliers who provide third-party verification reports from agencies like SGS or TÜV Rheinland.

Quartz tubes are versatile: Clear Quartz Tubes are used for UV sterilization lamps and halogen heaters due to high IR/UV transmission. Opaque/Milky White Quartz is preferred for infrared heaters to provide better heat diffusion. For semiconductor wafer processing, high-purity tubes with fire-polished ends are essential to prevent contamination and ensure vacuum-tight seals.

Quartz glass is highly fragile. You must mandate export-standard packaging, which includes individual plastic sleeves, pearl cotton (EPE) cushioning, and vacuum-sealed bundles inside reinforced plywood crates. Avoid standard cardboard boxes for sea freight. It is highly recommended to negotiate CIF (Cost, Insurance, and Freight) terms or purchase independent cargo insurance to cover 'All Risks' including breakage during transit.

Focus on Total Cost of Ownership (TCO) rather than just the unit price. Request a tiered pricing structure where the price drops by 10-15% for full container loads (FCL). Since quartz production is energy-intensive, ask about lead time stability during peak seasons. On Made-in-China.com, use the 'Secured Trading Service' to ensure your payment is only released to the supplier after you confirm the goods meet the quality standards defined in your Proforma Invoice.

Before placing a large order, request a paid sample to conduct a thermal shock test (heating to 1000°C and plunging into cold water). Verify the supplier's business license and export history through the Made-in-China.com company profile. Use Letter of Credit (L/C) for high-value transactions or Telegraphic Transfer (T/T) with a 30% deposit and 70% balance against the Bill of Lading (B/L) to maintain financial leverage.