Hanging, or trying to hang a Samsung UN65F8000 TV.
The lower mount holes use a standard M8 screw but the top mounting holes use an M6 with what I believe is a non-standard thread pitch. The M6 1.0 pitch screws thread 3/4 of a turn in and jam, as do both the fine and coarse 1/4" bolts. So I'm guessing I need to find M6 .75 pitch screws in around 35mm length.
3 hardware stores, Faastenal and Graingers have provided no joy. I'm hoping to avoid buying the Samsung picture mount just to get a couple of screws.
My assistant says we're gonna just force the screws we have in tomorrow if we can't find a solution. I want to avoid that!
Any help would be appreciated,

phil

In the accessory kit you will find two plastic pieces that look like hockey pucks with a screw coming out. These screw into the top mount points and have the M8 threaded inserts on the other side.

I was all ready to go "tap it out if you can't figure it out," and 1/4-28 would be a reasonable choice, even though it would be wrong, wrong, wrong to do it. I recently had a similar quest and I found a couple of places that would make the custom tap I'd need, but it would be around $60!

WAY better to find out what the hell they had in mind! If ksellers hadn't jumped in, it would have made sense to try every piece of hardware in the accessory kit, or, hell, CALL THE MANUFACTURER!

I have always found the screws provided with brackets, probably m6 to work just fine.

I've hung 4-6 of those without issue.

Can you provide what made and model of bracket used? I used the Chief LTTU without an issue, but a little pricey compare to others.

Thank you so much!
I called the client, who has had the set for almost a year and recently moved to a new house where he wanted it mounted above the fireplace (as they all do!), it was on it's little stand at the old house. I explained what to look for and it took him less than a minute to find the accessory box with the pucks in it.

Thanks again, all is good now, I was worried I might have to use the Stupid Samsung mount.

If you had to make something work, you could have just found something close and pounded them in. Carefully. Or, go under-sized and coat the tip with some JB Weld.

Did anybody ever determine for certain what size the upper bolt holes are on the back of the UN65F8000? My TV did not come with the "Wall Mount Adapters" and I would prefer to just get longer bolts that fit in those spaces. Are the holes for M6 .75 pitch bolts or some other size? My TV did not come with the accessories, so it's quite frustrating to figure out. Thank you in advance.

Michael,
Welcome to the site.
I think this issue deserves some research to find out what size to tap the holes to! M6 means 6 mm, which is .236," but thread names don't exactly match thread sizes. That is, the top and bottom of a thread can't both be, for instance, 6 mm. Let's say the top of the thread is 6 mm. That means the hole it goes into must be less that 6 mm, because the thread has to stick out far enough to get to the bottom of the screw thread.

Anyway, I'd play around with different screw sizes near that... since 1/4" is definitely larger, I'd probably try tapping it with that. And since the thread pitch is either 25.4 threads per inch (1 mm pitch) or about 34 threads per inch (.75 mm pitch), I'd go for the thread furthest from what's been cut. That would be 1/4-20 instead of 1/4-28.

Measure how much of that hole is threaded, and if it seems like it will work, decide for yourself what you're going to do; get a tap made for a blind hole; get some oil; and tap that! Hell, I'd tap it!

Thank you, Ernie. I will do the tapping process as an absolute last resort. I'd rather not go down that route if I can find out the size of bolt that fits in the manufactured fittings. It seems to be a mystery.

With all the complaints I've had regarding Samsung and their mounting holes, I've never found one where the top and bottom had different bolt sizes, except in a couple models that required the hockey puck adapters as previously mentioned. If the panel has a big step out towards the bottom, then there should be the adapter pieces. Given you are working with an F series, I assume this is a TV that someone has either moved or just finally decided to mount and those adapters are now missing.

Nothing a close match and an impact driver cant fix.

Don't forget some JB Weld

Update: I ordered a couple of M6 bolts from Lowes that are supposed to be fine thread. They don't fit either. Quite frustrating. I find it hard to believe that Samung would use a custom size and/or thread. More likely a hard to find standardized size, but I have no idea what it is. It also seems that out of the tons of people on the internet, nobody else knows either. It's almost a personal vendetta now.