controlling a swivel stand mirror

Stevolende

I bought a large swivel mirror on a stand from a charity shop last month.
It turned out to be without its side bolt/screws which I went to J.O'toole's to replace only to find out they were an Imperial size that they didn't have in.

They sent me onto Tripart. Where I got some generic bolts that are roughly the right size. not sure if they're long enough.

I finally got around to erecting the mirror yesterday and can't get the thing to stop swivelling backward until it's 90 degrees from the stand and about parallel with the floor. I took the thing apart again last night instead of leaving it like that overnight cos I was worried the mirror might fall and break.

Now I'm wondering if there is a way of controlling the swivel.
I don't have any history in working with constructing furniture so I could easily be missing something. Or could be that the reason that the relevant bolts were missing was that the previous owner couldn't control that swivel either. (Or alternatively moved house and misplaced them en route. Not sure where a piece fo furniture with imperial screws would originate either).

So is it just a question of making sure that the bolts are the full length to cover the width of the stand pieces they go through and the full length of the thread in the mirror side. Or is there a different type of bolt that I should be using instead of simply using generic bolts with the correct thread size.
Also not aware of the importance of washers. Only thought of not having any after trying to construct the thing. I don't think there si enough space for an extra nut between the stand and the mirror frame. there are threaded pieces that screw into the side of the mirror frame and have the bolts screw into them anyway.
The guy from O'Tooles showed me that I only needed to take down one of the bolts I got from the lower part of the frame and one of these side threaded pieces when I went down to Tripart.

I thought this would be really straightforward just a question of sticking pieces together but seems a little more complex. & I can't think what search engine terms to use to look things up on google or anywhere.

What else do I need?

Payton

Could you post a photo of the bolt/swivel mechanism?

Stevolende

Sorry meant to get a photo but thought I would try getting hold fo a longer bolt first.

Still not 100% sure if getting one that does cover the entire length of the thread is going to secure things.
Or if a washer is going to make any difference.

& really wish these bolts didn't need to be Imperial since getting hold of others means a specific trip since the shop is far from central. BUt hoping I might just get this sorted later this week.