... L/C opened. ISO Certification FAQ(Frequently Asked Questions)1. How to place an inquiry or order? Answer: ... very good reputation in drilling field.Available sizes: 60mm,65mm,76mm,93mm,95mm,98mm(3 7/8”), 114mm, ... 3/4”),127mm(5”)133.3mm(5 1/4”),139.7mm(5 1/2”),142.8mm(5 5/8”), ... 155.5mm(6 1/8”),158.7mm(6 1/4”), 165.1mm(6 1/2”)190.5mm(7 1/2”),193. ... 8”),295.3mm(11 5/8”)311.1mm(12 1/4”),346.0mm (13 5/8”),349.2mm ...