Ortofon AS-212 how to remove cartridge from headshell

[F575M]

Years ago, Angus sent me this Ortofon cartridge mounted on an Ortofon AS-212 headshell. I am at a loss as to how to remove the cartridge. He was very sick the last time I spoke to him, and I cannot reach him.

Using even the tiniest screwdriver is not feasible.

Can anyone help?

[Barry]

It looks as though the threaded bolts are captive and fixed to the headshell. The cartridge is secured by two nuts; which require a special nut driver.

The best you can do is to use some fine-tipped pliers and by gripping the nuts across their slots, gradually undo the nuts. You will have to reapply the jaws of the pliers to the nuts several times, but eventually you will succeed.

[Barry]

Further to the above, you can buy specialist nut drivers for slotted nuts. You would need to measure the diameter of the nut so as to buy the correct size driver.

It is most likely that the nuts are threaded for M2.5, and have an outer diameter of 4mm. But check to make sure.

[CageyH]

Swiss tools make one.
It is called a "screwdriver for slotted nuts" which might help you find more options.

[F575M]

Luckily, I found Angus. I am relieved that he is doing well. I may have to send him the headshell. Will these bits help?

https://www.grainger.com/product/5UXU8?gucid=N:N:PS:Paid:GGL:CSM-2295:UU5CX9:20800606:APZ_1&gclsrc=aw.ds&gad_source=4&gad_campaignid=22475795893&gclid=Cj0KCQjw5P7UBhDaARIsAOSlS1PrY-H6z9HG7PRQOpTr5uddQ-lBoiI8eBusE5BtDd-2mBJospLTSmYaAm0lEALw_wcB

[CageyH]

No idea how those sizes tie up to a M2.5 nut?

[Barry]

Luckily, I found Angus. I am relieved that he is doing well. I may have to send him the headshell. Will these bits help?

https://www.grainger.com/product/5UXU8?gucid=N:N:PS:Paid:GGL:CSM-2295:UU5CX9:20800606:APZ_1&gclsrc=aw.ds&gad_source=4&gad_campaignid=22475795893&gclid=Cj0KCQjw5P7UBhDaARIsAOSlS1PrY-H6z9HG7PRQOpTr5uddQ-lBoiI8eBusE5BtDd-2mBJospLTSmYaAm0lEALw_wcB

Glad you have found Angus well.

Apropos the bit set you cite, they are for US dimensioned parts. Also they don't look to be deep enough to encompass the threaded 'bolt'. What you need is an M2.5 screwdriver for slotted nuts; for example, as Kevin suggested above:

https://www.hoffmann-group.com/GB/en/houk/p/666600-2%2C5

https://assets.hoffmann-group.com/2/b/9/0/2b9045e9-32a0-4fdb-a3c6-c8679e84ade3/jpg_600_b666600.jpg