US Standard Size Joint Will Fit into European Standard Size Joint

Standard Taper Ground Glass Joints are interchangable.For either frosted, presicon-ground standard taper joints (same size),the inner ground surfaces (male joint) make a good seal with the outer(female joint)). The joint size is described by the form A/B. The first number A represents the outer diameter (OD) in millimeters (mm) at the widest point of the inner (male) joint and the second number B represents the length of the joint. For example, a 14/20 joint is 14 mm wide at the top (the widest part) and is 20 mm in longth. The joint has a standard taper 1:10, any two joints (male and female) with the same outside diameter (A)can fit into each other ,no matther how lenght the joints are. For example, a 24/40 (US standard size) joint on a condenser will fit into a 24/29 (European standard size)flask but the ground glass joint will protrude (40 - 29) 11mm into the flask.

 

Taper-Ground Joints

Joint Size Number Designation Approximate Diameter at Small End(mm) Approximate Length of Ground Zone(mm) Diameter of large End of Ground Zone(mm)

10/18

8.2

18

10

10/30

7

30

10.0

14/20

12.5

20

14.5

19/22

16.6

22

18.8

24/40

20

40

24.0

29/42

25

42

29.2

34/45

30

45

34.5

40/50

35

50

40.0

45/50

40

50

45.0

50/50

45

50

50.0

55/50

50

50

55.0

 

 

Spherical Ground Joints

Joint Size Number Designation Nominal Diameter of Ball(mm) Nominal Tube Inside Diameter(mm)
35/20 35 20
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