Compared to straight bevel gears, the improved contact ratio of spiral bevel gears allows them to rotate more smoothly offering superior noise and vibration quality. Custom-ordered gears Spiral bevel gears Capacity Gear size From module 0.5 to 6 Outer diameter To a diameter of approximately 300 mm Length To about 300 mm * Nissei can machine gears with specifications other than those listed above. Please contact us for more information. Contact Machining precision Gear precision From JIS B1704 Class 0.