How to Measure a Downstem (Length, Joint Size & Gender)

Nothing's more annoying than waiting on a new downstem and finding out it doesn't fit. Here's the three-minute measuring guide so you order right the first time.

1. Length

Pull your old downstem out and measure from the top of the ground joint to the very end of the stem. That number is your length.

Downstems come in half-inch increments, so round to the nearest one. The stem should reach down near the bottom of your water chamber without touching it — too long and it won't sit right, too short and you lose diffusion.

2. Joint size

Look at the ground joint — the frosted-looking part that slides into your piece. The two sizes you'll run into are 14mm and 19mm. If you still have your old downstem, the joint size usually matches the bowl that sat in it. A 14mm bowl means a 14mm downstem joint.

3. Gender

This one's simple: a male joint slides INTO the piece, a female joint receives the bowl. Your downstem's top joint and your bowl need to be opposite genders, same size.

Slits vs. popped holes

Cheap downstems have slits cut into the base — the cutting removes glass and weakens it. Our deluxe American-made downstems (blown here in Oregon) have the diffusion holes popped without removing any material, which makes them stronger and gives cleaner function. Either way, match your length, size, and gender first.

Shop replacement diffused downstems: https://420parts.com/category/downstems — flat $4.20 shipping, free over $60.