Clamps: Worm Gear vs Stepless

If you get into kegging, you're going to need clamps for your liquid and gas lines.

Silly Futurama reference

You basically have two choices: worm gear or "stepless."

From left: Stepless, worm gear, and worm gear
with thumb-twist handle

Worm Gear

Indentations left in PVC line after
~1 year under tension

The worm gear might be the one you're more familiar with. This clamp loosens and tightens by turning a worm gear (similar to a screw) that engages with slots stamped out of the ribbon. These slots make it a "stepped" clamp. They come in a variety of band widths and diameters. The most common variety is adjusted using a simple slotted screwdriver, though there are some that come with a thumb-twist handle attached.

PROS

• Simple and reliable
• Easy to find
• Virtually infinite adjustability
• Reusable
• Easy to apply and remove
• Requires no special tools (or none at all for thumb-twist)

Thumb-twist clamp with handle removed

CONS

• Can damage tubing
• Can come loose over time
• Potential to rust shut or jam
• Thumb-twist handle can come off
• Thumb-twist handle might get in the way

Worm gear clamps have a lot going for them, but they're not perfect. Their re-usability comes at the expense of potentially jamming. They will also damage your hoses over time, but this is less of a concern if you have thick-walled lines.

The thumb-twist clamps are a bit more expensive but you won't need a separate tool to open or close them. The downsides are the handles might be in the way on some connections, and if the handle breaks off you'll need a small wrench or a square-drive socket to make adjustments.

Stepless (aka Oetiker) 

Stepless clamp fully open (top)
and fully tightened
using a clamping tool

The stepless clamp relies on cinching rather than a worm gear to create and hold tension. Oetiker is a common brand name, but there are many manufacturers. The clamp is tightened using a tool that resembles end nippers. These clamps come in a range of diameters, but due to their design they can only be closed so far. Each clamp has its open diameter stamped on the side, usually in millimeters. A 12.8mm (0.5") clamp, for example can be tightened to 10.3mm (0.4"). I bought an inexpensive set of stepless clamps covering a range of sizes.

PROS

• More precise tension
• No mechanism to jam
• Won't loosen over time
• Less likely to damage hoses over time

CONS

• Requires a special tool to apply
• Single use - have to destroy clamp to remove it
• Cannot be loosened after its applied
• Narrower diameter range, so you need to find the right size

The biggest knocks on stepless is they are single-use and you need a "special" tool to install. I put that in quotes since you could tighten them with a pair of end nippers or a small pair of pliers, but not many homebrewers have end nippers.

So Which Is Better? Yes!

It's hard to say one clamp is inherently better than the other. Why pick one when you can use both? I keep both types around and use the one best suited to the job.

Worm Gear for Liquid, Temporary Lines
The simple fact that worm gears can be removed makes them great for liquid lines. At some point you will need to disconnect a hose for cleaning and that's much easier to do with a worm gear clamp. This type is a no-brainer for connections you'll be taking apart again and again.

Stepless for Gas, High-Pressure Lines
Stepless clamps are super tight and won't budge, so they are great for gas lines where disassembly for cleaning isn't likely. They are also worth considering on beverage lines that are under high pressure.