# Why is there a bulge at the top of my volumetric flask?

Sometimes volumetric flasks are designed with a bulge in the neck right below the stopper opening. What is the design intent of that bulge?

• I'd assume just an artifact of joining the ground glass joint to the neck of the flask. – MaxW Sep 29 '17 at 21:39
• It's also there to help you grip better. This way there's a stop if it starts to slide in your hand. – Zhe Sep 29 '17 at 23:49

Volumetric pipetts also have a large bulge in the middle, but it serves a different purpose – to keep the $\rm length : volume$ ratio minimal and still maintain quick liquid collection with high precision.