Constricted NMR tubes provide the most convenient way to flame-seal an air sensitive sample. Simply apply vacuum to the tube using our Tip-Off Manifold then heat the constricted portion and twist off; the sample is sealed in the tube. Order a constricted NMR tube by adding "CONS" to the product number of any Wilmad sample tube. Example: 507-PP-7CONS

Unless otherwise specified, constrictions are placed 1 inch from top of tube. Order tubes that are 1 inch longer than your required finished length.

Note: There is an additional charge for constriction. Please see table below, charges are per tube.

3 mm OD Tubes
3 mm OD Tubes

552-3-B

552-3-O

552-5

552-5-B

552-5-O

552-10

552-10-B

552-10-O

552-P

Due to the nature of glass, Extreme Caution should be exercised when using at elevated or reduced pressures since a tiny scratch on the glass surface would significantly lower the tensile strength. Adequate safety shielding should always be used when working in these conditions.