What size flat head screwdriver for trimpots?

[YurkshireLad]

This seems like a silly question, but what size flat head screwdriver works with trim pots? I've tried every damn screwdriver in my house, including one from a Christmas cracker, but they're all too thick. I looked through a datasheet I found but I couldn't see an sizing information, unless I missed it.

[Grandchuck]

I like these:

https://www.amazon.com/GC-ELECTRONICS-8608-TOOLS-piece/dp/B00DJS6WR0/ref=sr_1_5?keywords=electronic+alignment+tools&qid=1638042049&sr=8-5

One end goes over the extended adjustment screw on small trimmers (pots) and its collar keeps it engaged.  The other end is handy too.

[PartialDischarge]

That depends. Most can be adjusted with tools like H-90 from Bourns or ACCTRITOB308 from vishay.
The smallest ones require for example a Wera 118002, 1.5x0.23mm flat head

[jpanhalt]

This seems like a silly question, but what size flat head screwdriver works with trim pots? I've tried every damn screwdriver in my house, including one from a Christmas cracker, but they're all too thick. I looked through a datasheet I found but I couldn't see an sizing information, unless I missed it.

Amazing!  It IS a silly question.  Cut the tapered end off a toothpick and whittle the sides to make an appropriate screwdriver.  Or, buy a set of "jeweler's" screwdrivers.  The toothpick has the advantage of being non-magnetic.  I am sure you can buy a special tool on Amazon or eBay.

[CaptDon]

As another has said, nearly any set of 'Jewler's screwdrivers' has a size that works, also some of the 'eye glass repair' kits have a little screwdriver that fits. If the trimpot is within a high voltage cage such as the beam adjustment on Tektronix scopes and others you MUST use a plastic shank screwdriver or risk blowing up the entire blanking/high voltage section of the scope!! I fixed a few that got killed in that manner although the owners would never admit to it. In a couple cases the C.R.T. was also damaged!!

[ledtester]

Search for "ceramic screwdriver" on aliexpress / ebay.

[Doctorandus_P]

There is little to no standardization for flat screwdrivers (or there are so many standards that they're meaningless), so your best bet is to get a decent assortment of screwdrivers.

For general purpose small work I like the 4mm bits because you can store a lot of them in a small space.

Ceramic screwdrivers are also nice. They're non conductive and non-magnetic, and that makes them a great choice for trimming in high voltage areas or for adjustable inductors. Their extreme hardness also makes them wear resistant and they can take a lot of abuse when used as chisels or scrapers.

[T3sl4co1l]

If the smallest common/hardware store screwdriver doesn't do it, then a jeweller's set, or the plastic or ceramic types specific to electronics, will do.

I have a ready supply of the latter (plastic handle) because they come for free with scope probes...

Tim