What pilot hole size is for 6.5mm diameter self tapper pan head screw? For TV mount.

Forums › Home Workshop DIY › What pilot hole size is for 6.5mm diameter self tapper pan head screw? For TV mount.

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#1366244 14-Aug-2015 11:49

Huchiz:
DarthKermit: You didn't mention how large and heavy your TV is. Some of these 75+ inch behemoths that are available now are very heavy.

It's a smallish 40 inch, weights about 11kg. Previous owner had a last generation 32 inch on the mount. I checked that ccfl 32 LCDs are about 9-10kg. So I think weight shouldn't too demanding.

My concern is that the mount has a narraw base which will only attach to 1 stud. There are three screw holes s on the base from top to bottom, with slightly off center to left and right. There is plenty of space between each holes. Im thinking of drilling a new hole jist below the top hole, make it 4 screws, to make it stronger especially on the top side.

Nah, three lag bolts into a stud is plenty for that. You could swing off it, no problem.

Huchiz

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#1366245 14-Aug-2015 11:50

DarthKermit: You didn't mention how large and heavy your TV is. Some of these 75+ inch behemoths that are available now are very heavy.

My mount is similar to the one on photo, but with 3 screws on only one straight row on the base, with a little left and right off centre. I can be sure the build quality of the mount is very good.

Fred99

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#1366248 14-Aug-2015 11:52

Huchiz:
DarthKermit: You didn't mention how large and heavy your TV is. Some of these 75+ inch behemoths that are available now are very heavy.

It's a smallish 40 inch, weights about 11kg. Previous owner had a last generation 32 inch on the mount. I checked that ccfl 32 LCDs are about 9-10kg. So I think weight shouldn't too demanding.

My concern is that the mount has a narraw base which will only attach to 1 stud. There are three screw holes s on the base from top to bottom, with slightly off center to left and right. There is plenty of space between each holes. Im thinking of drilling a new hole jist below the top hole, make it 4 screws, to make it stronger especially on the top side.

Can you post a photo of the entire mount?
40" TV on a mount with a single stud sounds a bit dodgy/unstable to me.

Edit - Ok I see the photo above, and doubt that mount is really suitable for a 40" TV.

Huchiz

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Master Geek

#1366260 14-Aug-2015 12:09

Fred99:
Huchiz:
DarthKermit: You didn't mention how large and heavy your TV is. Some of these 75+ inch behemoths that are available now are very heavy.

It's a smallish 40 inch, weights about 11kg. Previous owner had a last generation 32 inch on the mount. I checked that ccfl 32 LCDs are about 9-10kg. So I think weight shouldn't too demanding.

My concern is that the mount has a narraw base which will only attach to 1 stud. There are three screw holes s on the base from top to bottom, with slightly off center to left and right. There is plenty of space between each holes. Im thinking of drilling a new hole jist below the top hole, make it 4 screws, to make it stronger especially on the top side.

Can you post a photo of the entire mount?
40" TV on a mount with a single stud sounds a bit dodgy/unstable to me.

Edit - Ok I see the photo above, and doubt that mount is really suitable for a 40" TV.

The reason I try to reuse it is the previous owner had a 32 inch on it jut fine. That old 32 ccfl TV is roughly the same weight as my new 40 led TV, about 10kg.

The actual mount is better quality than the photo, especially the base looks thicker and stronger. Ill try to upload photos tonight.

Huchiz

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#1366261 14-Aug-2015 12:12

That's why I have concern, and the reason of this post.

richms

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#1366316 14-Aug-2015 13:09

really want a mount that spans 2 studs to be secure. Friend had one like that and the whole stud itself would twist a little as the tv was moved, it worked the heads of the gib nails out of the gib on both sides around where the mount was. You could actually see the wall on the other side move slightly as the tv was swung backwards and fowards.

Richard rich.ms

Huchiz

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Master Geek

#1366530 14-Aug-2015 18:35

DarthKermit: What Fredd99 mentioned above is a better choice. They look like this:

and come in various lengths from about 20 mm to 100 mm. I wouldn't skimp on the length that you use.

If you don't mind me asking a very novice question, what is the usage of the un-thread shank of a screw? Like this one.
Should I try not to buy this kind for the project? Cheers.

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Huchiz

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#1366532 14-Aug-2015 18:39

richms: really want a mount that spans 2 studs to be secure. Friend had one like that and the whole stud itself would twist a little as the tv was moved, it worked the heads of the gib nails out of the gib on both sides around where the mount was. You could actually see the wall on the other side move slightly as the tv was swung backwards and fowards.

That scares me.

I checked a lot of similar models being sold in stores, most of them are rated as 20-30KG loading capacity, the least one is 15KG, if that means anythings. My TV is only 10.4KG.

The good news is we won't be moving the TV a lot once it is facing the sofa area, that is about 20-25 degrees of the center. Hope that's fine.

Huchiz

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Master Geek

#1366536 14-Aug-2015 18:45

That's the actual mount.

DarthKermit

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#1366539 14-Aug-2015 19:07

Huchiz:
DarthKermit: What Fredd99 mentioned above is a better choice. They look like this:

and come in various lengths from about 20 mm to 100 mm. I wouldn't skimp on the length that you use.

If you don't mind me asking a very novice question, what is the usage of the un-thread shank of a screw? Like this one.
Should I try not to buy this kind for the project? Cheers.

I think the idea with that type of fastener is when screwing one piece of material against another, for example, a flat piece of wood against a wall stud, the smooth part of the fastener slides inside the flat piece of wood (and matches its thickness) and the thread's what's used to secure the fastener into the stud.

In this case, the hex head is what holds the outer flat piece of wood. Of course, it wouldn't hurt to use a flat washer to increase the holding power of the fastener.

richms

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#1366540 14-Aug-2015 19:07

Huchiz:
If you don't mind me asking a very novice question, what is the usage of the un-thread shank of a screw? Like this one.
Should I try not to buy this kind for the project? Cheers.

When you are joining 2 things together you dont want the thread engaged in both of them, as that makes it impossible to pull up any gap between the 2 things since the position of the thread is locked into the one that it cuts relative to the other one. The plain part is so once the thread is thru into the bottom material, it can slip up and down the top material pulling it down to the bottom piece.

Richard rich.ms

Huchiz

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#1366541 14-Aug-2015 19:10

richms:
Huchiz:
If you don't mind me asking a very novice question, what is the usage of the un-thread shank of a screw? Like this one.
Should I try not to buy this kind for the project? Cheers.

When you are joining 2 things together you dont want the thread engaged in both of them, as that makes it impossible to pull up any gap between the 2 things since the position of the thread is locked into the one that it cuts relative to the other one. The plain part is so once the thread is thru into the bottom material, it can slip up and down the top material pulling it down to the bottom piece.

Makes sense!!!

Huchiz

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#1366542 14-Aug-2015 19:12

DarthKermit:
Huchiz:
DarthKermit: What Fredd99 mentioned above is a better choice. They look like this:

and come in various lengths from about 20 mm to 100 mm. I wouldn't skimp on the length that you use.

If you don't mind me asking a very novice question, what is the usage of the un-thread shank of a screw? Like this one.
Should I try not to buy this kind for the project? Cheers.

I think the idea with that type of fastener is when screwing one piece of material against another, for example, a flat piece of wood against a wall stud, the smooth part of the fastener slides inside the flat piece of wood (and matches its thickness) and the thread's what's used to secure the fastener into the stud.

In this case, the hex head is what holds the outer flat piece of wood. Of course, it wouldn't hurt to use a flat washer to increase the holding power of the fastener.

Yes I'll make sure there will be a apporiate washer.

DarthKermit

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#1366545 14-Aug-2015 19:29

If you have to use a fastener that is threaded all the way, you can overcome this by drilling a larger diameter hole in the outer material only so that the threads won't grip onto the material.

webwat

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#1366703 14-Aug-2015 23:36

Fred99: Unless it's an old house with rimu framing, I wouldn't drill a pilot hole at all, except perhaps a 1.5 or 2mm hole to check you've got it centred on the stud.
Pilot hole for rimu because it's so hard that you risk breaking the screw, but 4mm pilot hole should sort that.
I'd dump the pan head self-tappers and get some hex drive self-drilling tek screws of appropriate size, and a driver bit for them (only a few $)
The self tappers that were used probably came with a kit with the bracket, and were probably intended to be used with rawl plugs for fixing into concrete walls, not for fixing in to timber.
Posi/phillips head screws for secure fastening of hardware to timber are an abomination, even worse when they're not the right type of screw. Throw them out, and do it properly.

Yeah I wouldn't want more than a 2mm pilot if any. Normally a coach screw won't have a self drilling tip so pilot hole needs to be bigger to fit the shank as other posts...

Time to find a new industry!

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