On Sun, 14 Jul 2019 09:59:26 +0200, Tosspot
wrote:

On 14/07/2019 00:24, John B. wrote:
On Sat, 13 Jul 2019 17:01:15 +0200, Tosspot
wrote:

A discussion down there --v or up there --^ reminded me CO2 cartridges
come in a least two connectors, threaded and not. I've been caught by this.

Why the difference? Who cam first?

Years and years ago there was a device consisting of a glass bottle
with an attached CO2 cartridge, called a "siphon" was used to make
carbonated water for mixing drinks.
http://www.easywhip.com/soda-siphons.html

I believe that the original CO2 cartridges were threadless.

Having a peer about I found

https://www.amazon.com/POWERAXIS-Inf.../dp/B07Q2QDP6P

Which is compatible with both threaded and unthreaded. Good idea imho
as non threaded are cheap and easily available.

Well, I see Amazon list threaded cartridges for 16 oz for $9.19 which
seems pretty all right.
By the way, different cartridges contain different amounts of CO2,
which seems logical. See
http://www.bikepro.com/products/pumps/pumpc02.html
for a chart showing what each size cartridge will inflate which size
tire to what pressure.
Example:
A 12 oz cartridge will inflate a 700-25c tire to 87 psi and a 700-28c
tire to 84 psi. A 16 ox cartridge will inflate a 700-28c tire to
105psi, and a 700-32c tire to 90 psi
--
cheers,

John B.