Lab Clamps & Boss Heads

A burette clamp suits narrow, vertical glassware, while a utility clamp adjusts to grip a wider range of shapes and sizes.

Make sure the boss head matches your retort stand's rod diameter, since a loose fit won't hold its angle securely.

A retort ring supports a funnel or dish from below, while a clamp grips the item directly, so choose based on what the setup needs.

Any ground-glass joint under vacuum or reflux benefits from a joint clip to stop it working loose during a run.

A clamp grips the glassware or equipment itself, while a boss head is the connector that attaches that clamp to a retort stand's rod.

Most boss heads have an adjustable screw grip that fits a small range of rod diameters, but check the stated range before buying.

This usually means the clamp jaws are worn or the rubber lining has perished, so it can no longer grip firmly. Replace the clamp if this happens.

Not for simple setups at rest, but any connection under vacuum, reflux, or vibration benefits from a joint clip for extra security.

Yes, a retort ring works well for supporting beakers, dishes, or funnels of a matching diameter.