I'd not buy any chicom part, their threads are horrid and you run a higher risk of misalignment which could mean a baffle or endcap strike.
Any 1/2x28-5/8x24 adapter that fits your need and budget from a reputable e-tailer or local gunstore.
Here's 2 good options that won't add any real length and are reputable:
M11 & M41 Severe-Duty™ Muzzle Brakes: Engineered for 1/2-28 or 9/16-24 barrels. Easy install, perfect alignment, superior heat resistance.
precisionarmament.com
This 1/2×28 to 5/8×24 barrel thread adapter is made on CNC equipment and designed to ensure the highest level of tolerance to eliminate alignment issues.
www.silencercentral.com
$30 is nothing for an expensive can.
Other than those I listed,
JoeBobOutfitters
Brownells
Midway
Forgot to ask, are you putting a rifle can on, or a pistol can? A pistol can would typically use a fixed barrel spacer in the thread size you need without an adapter.