This item Promarx Megabold Retractable Ballpoint Pens with Comfort Grip, 1.6 mm, Black, 3 Count. BIC Velocity Bold Retractable Ball Pen, Bold Point (1.6mm), Black, 12-Count. OHTO Fude Ballpoint Pen Extra Bold, 1.5mm, black ink, 3 pens per Pack (Japan import) [Komainu-Dou Original Package]B-6: Brass: 10 mm: Swagelok® Tube Fitting: 3/8 in. Male NPT: View Product: B-6RP: Brass: 10 mm: Swagelok® Tube Fitting: 3/8 in. Male ISO Parallel Thread: View Product: B-6RS: Brass: 10 mm: Swagelok® Tube Fitting: 3/8 in. Male ISO Parallel Thread, Straight Shoulder: View Product: B-6RT: Brass: 10 mm:Jul 22, 2003 · A 1.6-mm, metal tube ultrasonic motor. Abstract: A miniaturized metal tube ultrasonic motor, the dimensions of which are 1.6 mm in diameter and 6 mm in length, was developed. Two flattened surfaces with 90 degrees were ground on the outer surface of the stator. Two PZT-based piezoelectric ceramics were bonded onto these flat surfaces.Answer: 6.3 mm = 0.25″. 6.3es.