VESA Screws M4, M6, M8: How to Get the Size and Length Right
Two reputable sources will hand you two different screws for the same television. Here is why that happens, and how to settle it with a measurement instead of a guess — including the length calculation almost nobody explains.
Quick answer
You need four machine screws matching your TV's tapped inserts — usually M4 on small sets and M6 or M8 on large panels — but the diameter is only half the answer. The length must equal your bracket and spacer stack plus the usable thread depth of the hole, minus a safety margin. Confirm both in your TV's manual before buying; a screw that bottoms out can damage the set.
- 1.Find the screw spec in your TV manual or spec sheet
- 2.Probe the empty hole to measure usable thread depth
- 3.Add bracket and spacer thickness, subtract a safety margin
⚠ Electrical safety warning
- Unplug the television from the mains and disconnect all cables before laying it down or handling the rear panel.
- A screw longer than the usable thread depth can bottom out and, if you keep tightening, transfer force into internal hardware or the panel's rear structure. Do not assume damage caused this way would be covered; check your manufacturer's warranty terms.
- Never force a screw that will not start by hand. Forcing it strips a threaded insert that cannot be easily repaired and permanently weakens the mounting point.
- Lay the television face-down only on a clean, flat, padded surface, with nothing underneath that presses against the back of the screen.
- Get a second person for lifting and for holding the set during the mount. Large panels are awkward rather than simply heavy, and a drop is unrecoverable.
- Fit all four screws. An incompletely fastened television can release later under vibration or a knock, and a falling set is a serious injury and tip-over hazard, particularly around children.
- If the arithmetic gives you no length that both clears the manufacturer's maximum and meets minimum thread engagement, do not improvise with washers or longer screws. Change the spacers or the mount, or have the installation done professionally.
Why two good sources give you two different screws
Search this question and you will hit a contradiction that nobody on the first page resolves. One set of guides indexes screw size by VESA hole pattern: 100 × 100 means M4, 200 × 200 means M6, larger patterns mean M8. Another set indexes by screen diagonal, sending small sets to M4 and pushing the largest ones towards M8, with the cut-off points varying from one guide to the next.
Run the same television through both and you can easily get two different answers. A large panel with a 200 × 200 pattern lands on M6 by the first index and M8 by the second. Both guides are describing real tendencies. Neither is describing your set.
The reason is that both indexes are proxies. Hole spacing is a proxy for cabinet size. Screen inches are a proxy for weight. Manufacturers choose the insert thread from the actual load and the actual chassis design, and they do not map either proxy to thread size one-for-one. VESA itself specifies the large interface as M6 or M8 without choosing between them, so an identical hole pattern is no guarantee of an identical thread.
So the useful move is not to find a better table. It is to invert the order: verify first, then use a table only to sanity-check what you found.
Where the real answer actually lives
Every manufacturer publishes this. It sits in the wall-mounting section of the user manual, on the printed spec sheet, and often on a label moulded into the rear cabinet next to the holes themselves.
Look for a compact notation rather than a sentence. The spec sheet for the LG 55VH7J, for example, gives the wall mount screw as a single line in the form 4-M6, L=16 mm (Max). That reads as: four screws, M6 thread, sixteen millimetres maximum length. Other brands and models use equivalent shorthand with their own figures, so look up the line for your exact model.
That word Max is the part most buyers skim past, and it is the part that protects the television. The manufacturer is not telling you what length to buy. It is telling you the ceiling you must not cross. Anything at or under that figure, provided it still reaches through your bracket and engages enough thread, is fine.
If your model's paperwork is gone, the manual is almost always downloadable from the brand's support site by entering the model number printed on the rear label. That is a far better use of ten minutes than guessing from a generic chart. Our guide on finding your TV's VESA pattern covers locating that label and reading the hole spacing; this article picks up at the thread itself.
VESA pattern vs. screw metric — a shortlist, not an answer
Use this only to check that what you read in the manual is plausible. If your manual and this table disagree, the manual wins without discussion.
| VESA interface family | Typical display class | Screw metric commonly specified | What you must still verify |
|---|---|---|---|
| MIS-B / MIS-C (small patterns) | Very small, light panels; rare on televisions | M4 | Whether the set has tapped inserts at all rather than a proprietary bracket |
| MIS-D (75 × 75 and 100 × 100 mm) | Monitors and compact televisions | Usually M4 | That all four holes share one thread size |
| MIS-E (200 × 100 mm) | Mid-size displays | Usually M4 | Whether the mount's supplied M4 hardware is long enough for a recessed back |
| MIS-F (200 × 200 mm and larger patterns) | Large flat panels; the family is defined by the hole pattern, not by a screen-size cut-off | M6 or M8 | Which of the two — the pattern alone does not tell you |
VESA's own overview of the Flat Display Mounting Interface describes the large-display interface as a rectangular pattern of four tapped holes, typically ISO M6 or M8. It describes the interface; it does not promise which thread your particular television received.
Thread pitch: the second number nobody checks
Diameter alone is not a thread spec. M6 describes a nominal six-millimetre shank; the pitch is what actually has to match the insert.
| Designation | Nominal shank diameter | ISO coarse pitch | How a mismatch shows up |
|---|---|---|---|
| M4 | 4 mm | 0.7 mm | Spins loose and never bites in an M6 or M8 insert |
| M6 | 6 mm | 1.0 mm | Will not start at all in an M4 hole; wobbles in an M8 hole |
| M8 | 8 mm | 1.25 mm | Will not start in an M6 hole — do not force it |
Fine-pitch variants of the same nominal diameter exist in engineering generally. If a correctly sized screw starts cleanly and then grinds or binds after a turn or two, stop turning. That resistance pattern points at a pitch problem, and forcing it will strip an insert you cannot easily repair.
A screw that is too long is the expensive mistake
The threaded holes on the back of a television are usually shallow bosses, not open passages into empty space. Behind or around them sit the rear chassis, internal boards, and the panel's own supporting structure.
A screw longer than the usable thread depth will bottom out before the bracket is tight. The bracket still feels loose, so the natural reaction is to keep turning. At that point the force stops going into clamping and starts going into whatever is behind the boss. That is how people crack a panel or push a fastener into internal hardware during what looked like a routine mount.
There is no warning noise before this happens. If you suspect a screw has bottomed out, stop and check your manufacturer's warranty terms before applying any more force, rather than assuming the damage would be covered. Measure before you buy, not after the screw stops turning.
The probe method: measuring usable thread depth
If your manual gives a maximum length, use it and skip to the arithmetic below. If it does not, or the paperwork is long gone, this is how you establish the ceiling yourself. It takes a few minutes and needs no special tools.
- 1
Unplug the television and lay it face down safely
Disconnect it from the mains and from every cable. Rest it screen-down on a clean, flat, padded surface — a blanket over a table, with nothing underneath that could press on the panel. Get a second person for anything you cannot lift comfortably alone.
⚠ Never rest a television face-down on an uneven surface or on top of anything that creates a pressure point behind the screen.
- 2
Clear the holes completely
Remove the factory stand and any transport screws already sitting in the VESA holes. Some sets arrive from the factory with short screws already fitted in the VESA holes. Check that no plastic plug, cable clip or trim panel is still covering a hole.
⚠ Keep the factory screws in a labelled bag. They are a useful reference sample, and you will want them if you ever refit the stand.
- 3
Insert a non-metallic probe until it stops
Use a thin wooden skewer, a plastic cable tie, or a trimmed plastic rod that passes freely into the hole. Slide it in gently until it meets resistance and stops on its own.
⚠ Do not push, tap or force the probe, and do not use a metal rod. You are locating the bottom of the boss, not making a new one.
- 4
Mark the probe flush with the rim
Holding the probe steady at the point it stopped, mark it exactly level with the outermost surface the bracket will press against. On a flat back that is the rim of the hole. On a curved or recessed back it is the highest surface around the hole, because that is what the bracket or spacer will actually touch.
- 5
Withdraw and measure to the mark
Pull the probe out and measure from the tip to the mark with a steel rule or calliper. That figure is your usable thread depth. Repeat on all four holes — on a curved back they will not always be equal, and the shallowest one governs the whole job.
- 6
Cross-check against the manual if you have one
If the manual states a maximum length and your probe figure is wildly different, trust the manual and work out what went wrong. A probe stopping short usually means a plug, packing material or a burr is still in the hole.
Turning the measurement into a screw length
Four quantities feed the sum. Get each one in millimetres before you order anything.
| Quantity | How you obtain it | How it enters the sum |
|---|---|---|
| Usable thread depth (D) | Probe method above, using the shallowest of the four holes | This is your ceiling |
| Bracket arm thickness (B) | Measure the mount's plate where the screw passes through, with a calliper or rule | Added |
| Spacer or washer stack (S) | Measure the actual spacers you will fit, stacked together | Added |
| Safety margin (M) | A few millimetres held back so the screw never reaches the bottom | Subtracted |
Maximum safe screw length = D + B + S − M. Buy at or below that figure, never above it. If the arithmetic leaves you a choice, the shorter option is the safer one as long as it still meets the engagement rule below.
The other failure: a screw that is too short
Undershooting is quieter but not harmless. A screw that only catches two or three threads is holding a heavy object on a very small amount of metal, and it can pull out later under vibration, a nudge, or a child grabbing the frame.
If your manual states a recommended length as well as a maximum, use it. If it only gives a maximum, the working rule we apply here is to keep at least as much thread engaged as the screw is wide — roughly six millimetres for an M6 and eight for an M8 — and to treat that as the floor, with the manufacturer's maximum as the ceiling.
If your bracket and spacer stack are so thick that no length satisfies both the floor and the ceiling, you have the wrong spacers or the wrong mount for that television — not a screw problem. Sourcing thinner spacers, or a mount with a slimmer arm, is the fix. What our guide on mid-installation screw and spacer problems addresses is exactly this squeeze once you are already on the ladder; the point of measuring first is not to end up there.
Mistakes that show up again and again
- Reusing the stand screws for the wall mount. They are cut for the stand's bracket thickness, which is rarely the same as the wall mount's, and they are often too short once a spacer goes in.
- Assuming the four screws in the mount's hardware bag are for the television. Mount kits tend to mix wall anchors and lag bolts for the wall side with metric machine screws for the television, and they often include more than one metric diameter. Identify which one matches your set's thread before you try any of them.
- Treating a curved or textured rear cabinet as flat. If the bracket cannot sit flush, spacers are not optional, and every spacer you add changes the length you needed.
- Buying by screen size because a chart said 55 inches means M8. Screen size predicts weight class, not thread.
- Forcing a screw that will not start. A correct screw threads in by hand for the first turns. Resistance at the very start is a diameter or pitch mismatch, and turning harder converts a shopping error into a stripped insert.
- Fitting only two of the four screws because the other two are awkward. All four holes exist because the load was calculated across four.
Before you buy the hardware
You have the exact model number
Read it off the rear label or from the TV's own settings menu under support or system information — not from the box or the retailer listing, which often cover a whole range.
You have the manufacturer's stated thread and maximum length
From the manual or spec sheet, in the 4-M6, L=16 mm (Max) shorthand or an equivalent sentence.
You have measured the bracket arm and any spacers
With a rule or calliper, on the actual parts you will use — not from the mount's marketing page.
You have run the sum on the shallowest hole
D + B + S − M, using the smallest of the four probe readings.
You have checked the engagement floor
Your chosen length still puts roughly one screw diameter of thread into the insert.
You are buying machine screws, not wood or self-tapping screws
The insert is already tapped. A self-tapping screw will cut a new, weaker thread over the top of the existing one.
Signs the screws you bought are not going to work
Stop and reassess if any of these appear. None of them improve with more force.
- The screw will not start by hand and needs a driver from the very first turn.
- It threads in smoothly for a turn or two, then binds sharply — a pitch mismatch, not a tight thread.
- It spins freely with no resistance and no clamping — the diameter is undersized for the insert.
- It stops turning while the bracket is still visibly loose or can be rocked — it has bottomed out and needs to be shorter, not tighter.
- The head pulls into the bracket hole instead of clamping against it — you need a washer or a screw with a larger head, not a longer one.
- Two holes accept the screw comfortably and two do not — check for a plug, a burr, or a bracket sitting at an angle on a curved back.
The short version
Diameter comes from the manufacturer's documentation, not from a chart indexed on screen inches or hole spacing. Those charts disagree with each other because they are both guessing from proxies.
Length is arithmetic you can do yourself: usable thread depth, plus bracket, plus spacers, minus a margin — with roughly one screw diameter of engagement as the floor and the manufacturer's stated maximum as the ceiling.
Do both before the hardware arrives. The failures that begin at the screw itself — a stripped insert, a damaged panel, a television that works loose from its bracket months later — start with a number that was assumed instead of measured.
Check these before you buy
- The exact model number, read from the rear label or the TV's settings menu, not from the box or a retailer listing.
- The manufacturer's stated thread size and maximum screw length, from the manual or spec sheet.
- A measured thickness for the mount's bracket arm where the screw passes through it.
- A measured thickness for the spacer or washer stack you will actually fit.
- Your usable thread depth from the probe method, taken from the shallowest of the four holes.
- Confirmation that your chosen length still gives roughly one screw diameter of thread engagement.
- Machine screws in the correct metric thread — not self-tapping or wood screws, which are for the wall side only.
- Washers if the bracket holes are larger than the screw heads.
Signs it will not fit
- The screw needs a driver from the very first turn instead of starting by hand.
- It turns smoothly for a turn or two and then binds sharply, indicating a thread pitch mismatch.
- It spins with no resistance and never clamps, indicating an undersized diameter.
- It stops turning while the bracket can still be rocked or lifted, indicating it has bottomed out.
- The head pulls through the bracket hole instead of clamping against the plate.
- Two holes accept the screw and two do not, pointing to an obstruction or a bracket sitting at an angle on a curved back.
- No available length simultaneously clears the manufacturer's maximum and meets minimum thread engagement — the spacer stack or the mount itself is wrong for this television.
A visual match does not guarantee compatibility. Check the exact reference printed on your TV or on the original part before ordering anything.
Frequently asked questions
Do I need M6 or M8 for a 55-inch TV?+
Screen size does not determine it. Sets of that size exist with both, and some use M4. The 200 × 200 pattern common at that size is specified by VESA as M6 or M8 without choosing between them. Read the thread from your model's manual, spec sheet or rear label, then use the probe method to establish the maximum length.
What happens if the screw is too long?+
It bottoms out inside the threaded boss before the bracket is clamped. Because the bracket still feels loose, people keep turning, and that force transfers into the chassis, internal hardware or the panel's rear structure. It can crack a panel, and whether that is covered is a question for your manufacturer's warranty terms rather than something to assume. It is one of the mistakes here that can do irreversible damage to the set.
Can I reuse the screws that held the TV stand?+
Usually not. They are cut for the stand bracket's thickness, which rarely matches a wall mount's arm, and they leave no allowance for spacers. Keep them as a reference sample for thread size, but measure a fresh length for the mount.
How do I know the thread pitch, not just the diameter?+
For M4, M6 and M8, the ISO coarse pitches are 0.7 mm, 1.0 mm and 1.25 mm respectively, and that is what most televisions use. The practical test is behaviour: a correct screw starts by hand and turns smoothly. One that starts and then binds after a turn or two is a pitch mismatch — stop before you strip the insert.
My TV's back is curved, so the bracket does not sit flat. What now?+
That is what spacers are for, and it changes your arithmetic. Measure the spacer stack you will actually fit and add it to the required length. Also probe all four holes separately, because on a curved back the usable depths often differ, and the shallowest hole sets the limit for all four screws.
Are self-tapping or wood screws ever acceptable?+
Not into the TV. The VESA holes are already tapped for machine screws. A self-tapping screw cuts a new and weaker thread over the existing one and compromises the insert permanently. Self-tapping and lag screws in a mount kit are for the wall side of the job only.
Sources
- Official source: VESA — Flat Display Mounting Interface (FDMI) Overview · 2026-07-20www.vesa.org
- Official source: VESA — Mounting Standard · 2026-07-20vesa.org
- Official source: LG — Display specification sheet showing wall mount screw notation (4-M6, L=16mm Max) · 2026-07-20www.lg.com
- Official source: LG USA Support — Installation Screws · 2026-07-20www.lg.com
- Official source: LG UK Support — How to wall mount your LG TV · 2026-07-20www.lg.com
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