How to Cut and Fire Polish Glass Tubing

Cutting Glass Tubing

Glass tubing may be used to make simple pipettes.
Glass tubing may be used to make simple pipettes. Andy Sotiriou/Getty Images

Glass tubing is sold in a variety of lengths. Typical lengths are 6" (~150 mm), 12" (~300 mm) and by the foot. There is a good chance you'll need to cut the tubing to make it the right size for your project or experiment, so here is what to do.

  1. Use the edge of a steel file to score or notch the glass perpendicular to its length. A single score works best. If you saw back and forth, you're asking for a messy break. Also, a light score works better than a deep cut.
  2. Put on eye protection and heavy gloves. If you don't have gloves, you can minimize a chance of being cut by wrapping the tubing in a towel.
  3. Place your thumbs on either side of the notch and apply gentle pressure until the tubing snaps in two.
  4. The ends of the tubing will be extremely sharp, so you'll need to fire polish them before using the tubing. Fire polish the tubing by holding the sharp ends of the glass in the flame of an alcohol lamp or gas burner. Turn the tubing so that it is heated evenly. Stop when the ends are smooth. Be careful that you don't leave the glass in the flame too long, which melts the tubing and may block the ends.
  5. Allow the glass tubing to cool before using it.