Jointed Powder Funnel, 70mm - 29/32 Joint Size - Borosilicate Glass

This powder funnel is made from borosilicate 3.3 glass with a 70mm cone at a 60 degree angle and a 29/32 ground joint stem. It measures 2.75 inches (70mm) across the mouth and 4.75 inches in total length, with a stem 2.5 inches long. The stem bore is wide and short, which allows powdered and granular solids to fall through under their own weight with a tap on the rim. The walls are thick and uniform, giving the funnel durability under the knocking that transferring solids involves. The ground joint stem seats into a 29/32 socket so the funnel locks into the flask instead of balancing on the neck. That leaves both hands free for the weighing boat and keeps solid off the ground glass sealing surface, where a stray grain can score the joint or prevent a stopper from seating. The 29/32 stem matches the wider necks used on round bottom flasks and reaction vessels. Borosilicate glass is chemically inert and autoclavable.