E-Bay is always worth a try.

Was asked to find 50 or so oddball head and length size combination 6BA for a piano guy. E-Bay came up trumps with something so close that he was happy. Had to get a pack of 100 but the price was very good. I really really didn't fancy cutting down 50 of a more standard size.

Clive

You may have better luck looking for Countersunk BA Allen screws.

Howard

Will Pozi do?

eBay Link to 6BA x 1/4 Pozi CSK

Brian G

Edit: Nick beat me to it

Edited By Brian G on 26/05/2023 18:36:08

Having read this post, I have some BA bolts/nuts that I’m never going to use. I’ve also got BA taps and dies.
I only use metric, but have a lot of other taps/dies that I’ll never use as well.
I’ve added them all in the classified section – they’re all free, all I ask is that you cover postage.
(and ideally take all of my non metric stuff listed in one go)

For new work, M2.5 and M3 Phillips CSK would be better.

Both are nothing-special current production, whereas BA is becoming ‘new old stock’ only.  If someone has to fix Bo’sun’s thingy in 50 years time, them having to find BA in that configuration will be a right pain.  Metric will be easy to source for the foreseeable future.

Dave

Depends on the context, Bo’sun

The Phillips recess was designed to cam-out, to avoid jamming

The Pozidriv recess was designed with parallel sides, specifically to avoid cam-out.

MichaelG.

On 18 December 2023 at 09:43 Michael Gilligan Said:

Depends on the context, Bo’sun

The Phillips recess was designed to cam-out, to avoid jamming

The Pozidriv recess was designed with parallel sides, specifically to avoid cam-out.

MichaelG.

 

So for most manual workshop jobs, Pozidriv is better because there’s less chance of chewing the head.   Phillips were designed for factory work where a machine drives the screw in and automatically stops when the bit cams out.  Ideal for repetition work, including home power tools.  (More-or-less, factory screwdriving can be tightly controlled, whereas DIY conditions vary,).   Controlled cam out is good, but unwanted camming is a problem.   The air turns blue every time I remove a tight or corroded Phillips screw!   Pozidriv screws in the same condition are far more likely to come out gracefully.

Although Phillips and Pozidriv look similar, their screwdrivers aren’t interchangeable, and using the wrong one mangles the screw.  It’s impossible to avoid tooling up for both because they are so common.

Other alternatives: Allan hex, which is a good system.  Increasingly common are Torx and a host of security system heads.   Torx is a shade better than Pozidriv, but only used I think on posh machine screws.   The security systems are intended to keep casual intruders out of equipment,  making having a set of special drivers essential  for many types of repair work.  Outside the UK, probably a few local systems too. Though I’ve never seen one in the UK I believe Robertson heads aren’t unusual in North America.

Dave

Dave you are a bit behind the times, Torx are now common for wood screws as they stay engaged far better when driving with a cordless impact driver which just about every tradesman now has. Square drive is the usual for pocket hole screws and if you can get hold of “pro” bits they fit pozi and Phillips though not seen them in the usual 1/4hex drive

On 18 December 2023 at 14:15 Robert Butler Said:

Don’t forget JIS crosshead screws used by the Japanese and the cause of much trouble if using Posidrive or Phillips drivers which results in damaged screw heads.

Robert Butler

Agreed, and they’re often found on Japanese motorbikes, bicycle components (e.g. Shimano) and garden power equipment. A small punched dot on the fastener head usually identifies a JIS screw, or at least used to.

One recently evolved area of confusion in all of this for the home mechanic is that the JIS and JCIS standards were absorbed in 2008 into the same ISO standards as Phillips screws (ISO 8764-1 PH  and ISO 8764-2 PH), so manufacturers of JIS/JCIS compatible drivers and bits are being anachronistic if they advertise drivers and bits as being to JIS/JCIS standards. Even Vessel, who were involved in the creation of the JIS standard, no longer promote or mark their crosshead drivers/bits as JIS, but as PH.

Whether every driver or bit manufactured today to the current ISO 8764-1/2 PH standards is as compatible with JIS fasteners as Vessel ones (and those of other Japanese manufacturers such as NAC) still are is uncertain. I suspect the answer is no.

The cam out isn’t always a bad thing. It stops screws being forced in so tight that they break. Even self drilling wood screws are often better used with a pilot hole.

When I bought my first Honda bike, nearly 50 years ago now, I replaced all of their soft screws with ones using allen keys. kits to do that were sold at the time. it was also when I bought my hammed impact wrench, which is still good for removing screws.