By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

BA Allen Keys

Looking for BA Allen Keys

All Topics | Latest Posts

Search for:  in Thread Title in  
Bob Unitt 117/11/2021 13:04:32
222 forum posts
33 photos

Does anyone know where I can get BA Allen Keys, preferably in a set ? I've tried the usual suppliers, but no luck sad

DMR17/11/2021 13:10:52
128 forum posts
14 photos

BA was never metric to my knowledge. You need an imperial inches set.

Clive Brown 117/11/2021 13:11:32
863 forum posts
47 photos

AFAIK they don't exist. All the socket head BA fasteners I've ever used have fractional imperial sockets.

JasonB17/11/2021 13:12:13
23042 forum posts
2769 photos
1 articles

Should not be a problem getting 2, 2.4 and 4mm for the common even numbered BA cap heads which are 6, 4 and 2BA, Someone Like Model Fixings have key, tee wrenches and ball ended drivers in those sizes

That is what I use and they all fit, if not go looking for 5/64, 3/32 and 5/32" again not too hard to find as are 0.9mm (0.035inch) and 1.27mm (0.050inch) which fit BA grub screws. Same supplier does them too.


Edited By JasonB on 17/11/2021 13:18:16

Mark Rand17/11/2021 13:14:08
1309 forum posts
35 photos

Use normal imperial Allen keys. There are no separate BA Allen keys

Nigel Bennett17/11/2021 14:01:05
460 forum posts
20 photos

Machine Mart do a set of miniature Allen keys Product Code 040215196 which are small metric and Imperial.

Bob Unitt 117/11/2021 15:37:21
222 forum posts
33 photos

Thanks for all the replies. The reason I asked was because I have a set of 4 BA capscrews which neither my metric nor my imperial allen keys fit, but I have an allen key supplied as 4 BA by a model engineering firm which fits them perfectly.

JasonB17/11/2021 16:06:04
23042 forum posts
2769 photos
1 articles

Sounds like you have some odd 4BA screws if imperial keys won't fit. This is a 4BA with a nominal 3/32" key which fits fine. Details of key sizes can be found here and as I said the metric ones fit too.


Edited By JasonB on 17/11/2021 16:06:14

bernard towers17/11/2021 16:20:24
689 forum posts
141 photos

ITEMS , Mail order do all the keys and they are good quality.

Tim Stevens17/11/2021 17:54:02
1622 forum posts

It is one of the better ideas among the dozens of fastener shapes and sizes, that Whitworth, BSF, UNC, UNF, UNEF and others all take the standard Inch sizes of Allen key.

And beware - some supplies of BSF from the left-hand edge of the Pacific come with socket heads for metric Allen keys.

Cheers, Tim

Brian Morehen19/11/2021 20:12:15
189 forum posts
11 photos

have used BA allen screws for years down to 8 BA . AF allen keys have always been correct ,I believe these also been in use be fore Metric appeared

regards Bee,m

V8Eng19/11/2021 21:22:54
1730 forum posts
6 photos

Some time ago bought a metric/imperial set on offer from Screwfix in a handy flip case.

They seem to fit anything (within size range) that I’ve tried so far and appear tough.


Edited By V8Eng on 19/11/2021 21:24:13

ega19/11/2021 23:31:02
2565 forum posts
203 photos

By way of addition to Jason's link, 8BA set screws take a 0.035" key. For the 1/16" sizes and above I identify them by 1/64"s, so that, eg, a 5/32" is a number 10 in my system.

The small L-shaped keys can be quite flexible and when more torque is required I use the 1/4" AF shank bits in a holder; these seem to be available down to 0.050".

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at

Latest Forum Posts
Support Our Partners
Rapid RC
Eccentric July 5 2018
Eccentric Engineering
Subscription Offer

Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest