Hexagon heads size for British Association hex fasteners (screws, bolts)

[wce4]

Looking for a table, chart or cheat sheet for the hex head (imperial size preferred) sizes for BA hex head bolts.
H, F and G size as shown in included jpg dwg.
5BA, 6BA, 7BA, 8BA, 10BA and 12BA


Thanks in advance for any information.

 

[djc]

Please see:

https://eicac.co.uk/british-association-fastener-dimensions/
(does not include 12BA)

Another:

https://www.ba-bolts.co.uk/faq.html
The horse's mouth:



(12BA bolts are not listed in the above Standard)

 

[wce4]

Please see:

https://eicac.co.uk/british-association-fastener-dimensions/
(does not include 12BA)

Another:

https://www.ba-bolts.co.uk/faq.html
The horse's mouth:



(12BA bolts are not listed in the above Standard)

Thank you for providing me this information , you made my day.

 

[Weldsol]

Also in the uk you can get BA bolts with a one size smaller head (more scale looking )
Check this site
https://www.ekpsupplies.com/
Paul

 

[abby]

I have several sizes of hex BA screws if you just need a small quantity , some with a size smaller head to give better appearance (as already said)
Dan.

 

[wce4]

Also in the uk you can get BA bolts with a one size smaller head (more scale looking )
Check this site
https://www.ekpsupplies.com/
Paul

Weldsol thank you for the info and the link.

 

[wce4]

I have several sizes of hex BA screws if you just need a small quantity , some with a size smaller head to give better appearance (as already said)
Dan.

Abby Thank you for the offer but I am going to try and manufacture my own for the fun, experience and plus the bragging rights.

 

[abby]

A good idea to make your own if you only need a few , I have a coventry die head with 6,8,10 and 12 BA dies.
.
Here's a video I made some years ago , I needed some small screws for something , can't remember what though !
Dan

 

[PeterDRG]

If you are making your own, you will find set of running down cutters very useful. Each one is sized to a specific BA screw thread. With a single pass, hex bar is reduced, ready for tapping. I*m not sure they are still available. Mine are Dormer.

 

[PeterDRG]

I*ve a Coventry Die Head too,but only for a couple of sizes

 

[wce4]

If you are making your own, you will find set of running down cutters very useful. Each one is sized to a specific BA screw thread. With a single pass, hex bar is reduced, ready for tapping. I*m not sure they are still available. Mine are Dormer.

Thank you for the information, I never knew such an item exists.

 

[wce4]

I have a question where do you purchase hex screw stock for the hobbyist,
or does one need to machine his own ?
I am looking for hex bar stock to machine some 7ba screws. (0.172 hex)

 

[Jasonb]

It's getting harder to come buy in the UK let alone the parts of the world where BA is not commonly used, Even some of the makers of BA fixings are having to resort to metric sizes for some BA hex.

So either make your own from round or find a near match such as 11/64 from here Hex & Square - Steel & Stainless Steel

 

[djc]

I have a question where do you purchase hex screw stock for the hobbyist,

In Tubal Cain's 'Model Engineer's Handbook', he discusses this issue (page 4.13 of third edition) and suggests 'nearest metric size', noting that the error is around 0.004" on the big size.

 

[wce4]

It's getting harder to come buy in the UK let alone the parts of the world where BA is not commonly used, Even some of the makers of BA fixings are having to resort to metric sizes for some BA hex.

So either make your own from round or find a near match such as 11/64 from here Hex & Square - Steel & Stainless Steel

Thanks Jasonb for the link to Godshall's Custom Machining & Live Stream unfortunately they are sold out of 11/64 hex 12L14 stock. I will give them a call on Monday to see when and if they will be restocking it.

 

[wce4]

In Tubal Cain's 'Model Engineer's Handbook', he discusses this issue (page 4.13 of third edition) and suggests 'nearest metric size', noting that the error is around 0.004" on the big size.

Thanks for the info. djc , I just place a order for the handbook.

 

[Jasonb]

If you are going as far as deviating from standard BA hex then it may be worth looking at a smaller size. One size smaller is often used for models particularly as the BA size increases for example the 2BA fixings supplied with the 1" x 2" Stuart Victoria, beam, etc look way too big.

These days I tend to use metric rather than BA for fixings and where 7BA is specified would opt for M2.5 which is so close in major diameter to 7BA it is not worth considering the difference. However I do use small hex metric heads and nuts and for the M2.5 thread they have a 3.5mm (0.138") A/F which looks far more like an old hex fixing than a 7BA or the even larger standard M2.5 hex size.

 

[ds engines]

I have a question where do you purchase hex screw stock for the hobbyist,
or does one need to machine his own ?
I am looking for hex bar stock to machine some 7ba screws. (0.172 hex)

Hi I use a company in cheltenham they stock all ba sizes in all materials www.ba-bolts.co.uk