Oil Sight Glass / Oil Level Indicator

Factory-direct oil sight glasses and oil level indicators — compact visual inspection windows for monitoring oil levels and fluid conditions in gearboxes, compressors, hydraulic systems, and industrial machinery. Available in brass and stainless steel. Custom sizes and OEM orders welcome.

Brass vs. Stainless Steel Oil Sight Glass

Type Material Typical Use
Brass oil sight glass Brass body + borosilicate glass Gearboxes, pumps, general machinery
Stainless steel oil sight glass 304/316 SS body + borosilicate glass Food processing, pharmaceutical, corrosive environments

Key Properties

  • Glass window: Borosilicate glass — oil-resistant, high clarity, long service life
  • Max. operating temperature: Up to 120°C (standard); higher on request
  • Pressure rating: Up to 10 bar (standard models)
  • Thread standards: BSP, NPT, metric — specify on order
  • Seal options: NBR, PTFE, silicone — compatible with most lubricants and hydraulic fluids
  • Custom sizes available from M12 to M60+ thread diameter

Typical Applications

  • Gearboxes and reducers — oil level monitoring
  • Compressors and air dryers — lubricant inspection
  • Hydraulic power units — fluid level and condition check
  • CNC machines and industrial equipment — routine maintenance windows
  • Food and beverage processing — hygienic oil level indicators
  • Marine and offshore equipment — corrosion-resistant monitoring

Installation Notes

Oil sight glasses are threaded directly into the equipment housing. Ensure thread type and size match your equipment specification. Use appropriate sealant tape or compound on threads. For high-vibration environments, consider locking compound to prevent loosening.

Need a custom thread size, material, or seal type? Contact us for a quote within 24 hours →