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Ball lock and pin lock keg posts and 5 gal Cornelius keg: post threads, wrench sizes, keg height and diameter

What thread and wrench size is a ball lock keg post, and how big is a corny keg? · Standard part · basis: Published post-thread reference (HomebrewFinds), Wikipedia (Cornelius keg), retailer listings (Kegoutlet, Homebrewing.org); numbers only

Also called: ball lock post dimensions, 7/16-20 keg post, keg post thread size, corny keg dimensions, cornelius keg size, ball lock vs pin lock, 19/32-18 post, keg post wrench size, 5 gallon corny keg height, pin lock post thread

Exact dimensions. True size, with no printing tolerance added.

sizes: 6 in table

Notes

The common post thread is NOT 7/16-20. Cornelius and AEB kegs use 19/32-18 on both posts; Firestone and John Wood kegs usually use 9/16-18 (Wikipedia: Cornelius 19/32 in 18 TPI, Firestone/John Wood 9/16 in 18 TPI). 7/16-20 is the 1/4 in SAE flare / AN -4 thread, which is what a flare-nut gas or beer line screws onto; it is not the post.
Two wrench sizes cover nearly all ball lock posts, 11/16 in and 7/8 in (6- or 12-point); pin lock posts take 13/16 in and need a notched socket.
Ball lock and pin lock differ by the poppet and connector, not by the post thread: ball lock gas and liquid posts are the same thread and are told apart by the connector, pin lock by 2 pins (gas) or 3 pins (liquid).
A 5 gal Cornelius-style ball lock keg is 8.5 in (216 mm) diameter and 25 in (635 mm) tall in maker listings; the pin lock is 9 in (229 mm) by 23 in (584 mm). Wikipedia lists 24.75 in for the ball lock and 8.5 in / 9 in diameters. Makers vary by about an inch, so measure your keg before building a kegerator.
Not published by any maker we could read, so left out (no file): post outside diameter and height, poppet size, post o-ring sizes, lid opening. KegLand lists only a 20 mm long 1/4 in BSP tail on its welded post, and retail pages give no AS568 size for post o-rings.

Ball lock and pin lock keg posts and 5 gal Cornelius keg: post… size chart

keg / post	gas post thread (TPI 18)	liquid post thread (TPI 18)	post wrench (hex)
Cornelius ball lock (Pepsi style)	19/32-18	19/32-18	11/16 or 7/8 (6- or 12-point)
Cornelius pin lock (Coca-Cola style)	19/32-18 (2 pin)	19/32-18 (3 pin)	13/16 (notched socket)
AEB ball lock	19/32-18	19/32-18	same as Cornelius
Firestone / John Wood ball lock (V, VI, Super Challenger)	9/16-18	9/16-18	-
Firestone / John Wood pin lock (A, R)	9/16-18 (2 pin)	9/16-18 (3 pin)	-
Firestone Challenger (racetrack)	11/16-18	3/4-18	-

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

HomebrewFinds	Homebrew keg post thread size reference	web	Publisher's page; dimensions are facts
HomebrewFinds	Homebrew keg post sizes, ball lock and pin lock	web	Publisher's page; dimensions are facts
Wikipedia	Cornelius keg	web	Publisher's page; dimensions are facts
Kegoutlet	Cornelius kegs (ball lock 25 x 8.5 in, pin lock 23 x 9 in)	web	Publisher's page; dimensions are facts
Homebrewing.org (AIH)	New 5 gallon corny keg, ball lock	web	Publisher's page; dimensions are facts
KegLand	Ball lock post with 1/4 in bulkhead (20 mm thread)	web	Publisher's page; dimensions are facts

Xem scan

File coming

No downloadable true-size file yet: the published figures do not fix the whole shape, and Xem never guesses a number. A measured scan is planned; request it and it moves up.

Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.

Set it up →

Plain text: sheet.txt · JSON: /api/geometry?object=keg-posts-and-cornelius-kegs

Schematic, not to scale.