M4 vs M6 vs M8 TV Mount Screws

Choosing between M4, M6, and M8 TV mount screws starts with the threaded inserts on the back of the TV—not with the mount bracket. The correct screw must match the TV’s insert diameter and thread pitch, then provide a suitable length through the bracket, washer, and any required spacer.

M4, M6, and M8 refer to nominal screw diameters:

• M4: approximately 4 mm in nominal diameter
• M6: approximately 6 mm in nominal diameter
• M8: approximately 8 mm in nominal diameter

These labels do not tell you the screw length, thread pitch, head style, or whether the screw is suitable for a particular TV. Use the TV and mount manufacturer’s instructions as the primary source.

M4 vs. M6 vs. M8 at a glance

Screw designation	What it describes	What it does not describe
M4	Nominal thread diameter of about 4 mm	Length, pitch, head type, or load rating
M6	Nominal thread diameter of about 6 mm	Whether it fits a particular TV or mount
M8	Nominal thread diameter of about 8 mm	Required engagement depth or spacer arrangement

The diameter is only one part of the fit. A screw with the right diameter but the wrong pitch may not enter the insert correctly. A screw with the right diameter and pitch can still be too long, too short, or unsuitable with the bracket and spacers.

How to identify the correct screw diameter

1. Check the TV documentation first

Look for the mounting hardware section in the TV’s installation guide. It may specify:

• Screw diameter
• Thread pitch
• Screw length
• Washer requirements
• Spacer requirements
• Permitted mounting orientation
• VESA pattern or mounting-hole spacing

If the TV included mounting screws, compare them with the mount hardware before installation. Do not assume that a screw supplied with a universal mount is automatically correct for every TV.

2. Inspect the existing hardware

If you have a screw that came with the TV, use it as a reference. Compare its threaded portion with the replacement screw, not just its head.

A screw’s designation follows this general pattern:

M6 × length

The first number identifies the nominal diameter. The length must be verified separately, and the thread pitch may also be specified. For example, two screws can both be M6 while having different thread characteristics or lengths.

3. Measure the threaded portion carefully

A caliper can help estimate the outside diameter of a screw’s threads. Measure across the widest part of the threaded section, rather than across the head or washer.

Approximate diameter checks:

• Near 4 mm suggests M4
• Near 6 mm suggests M6
• Near 8 mm suggests M8

This is a screening method, not a complete compatibility test. Diameter alone cannot confirm thread pitch or safe length. If the result is unclear, use a thread gauge or obtain confirmation from the TV manufacturer.

4. Test the thread without force

With the TV supported securely and the bracket held in the intended position, turn the screw by hand. It should engage smoothly for several turns without binding.

Stop immediately if:

• The screw begins crooked
• It turns tightly almost at once
• The screw appears to cross-thread
• The screw bottoms out before the bracket is secure
• The screw continues turning without clamping the bracket

Never force an M4, M6, or M8 screw into an insert. A forced screw can damage the insert or make later mounting unsafe.

Diameter is not the only fit requirement

Thread pitch

Thread pitch is the distance between adjacent threads. The screw diameter can be correct while the pitch is wrong.

Do not substitute a screw solely because it has the same M designation. If the screw does not start smoothly by hand, it is not the correct screw for that insert.

Screw length

The required length depends on the total thickness of the mounting stack:

Required screw length = bracket thickness + washer thickness + spacer thickness + suitable thread engagement

This is a planning relationship, not a universal length specification. The acceptable engagement depth must come from the TV instructions, mount instructions, or the manufacturer.

A screw that is too short may not hold enough thread. A screw that is too long may bottom out inside the TV, damage internal components, or prevent the bracket from clamping correctly. Do not estimate a safe length from the TV’s exterior depth.

Washers and spacers

Washers can distribute clamping force under the screw head. Spacers may be necessary when the back of the TV is curved, recessed, or obstructed around the VESA mounting holes.

Use spacers only in the arrangement specified by the TV or mount instructions. Avoid stacking random washers or spacers to make an incorrect screw appear to fit. The bracket should sit securely, and the screw should clamp the assembly without pressing the bracket into the TV’s rear panel.

Verify the VESA pattern before mounting

Screw diameter and VESA size are related to the mounting interface, but they are not the same measurement.

The VESA pattern is the horizontal and vertical distance between the TV’s threaded inserts. Measure center to center:

• Horizontal spacing: center of one insert to center of the opposite insert
• Vertical spacing: center of the upper insert to center of the lower insert

For example:

VESA pattern = horizontal spacing × vertical spacing

A TV can have a VESA pattern that fits a mount while still requiring a specific screw diameter, pitch, length, and spacer setup. Confirm both:

1. The mount supports the TV’s VESA pattern.
2. The hardware matches the TV’s inserts and the bracket thickness.

Also check whether the inserts are centered on the TV. Some screens have mounting holes positioned below or above the physical center, which affects the final viewing height.

Plan the TV center and mount position

Before tightening anything, decide where the screen center should sit on the wall. A simple planning formula is:

TV center height = bottom height + (TV height / 2)

If the TV’s VESA holes are offset from its center, the bracket position cannot be chosen by measuring only from the screen edges. Account for:

• TV height and width
• VESA-hole position relative to the screen
• Bracket adjustment range
• Desired viewing height
• Furniture or soundbar clearance
• Baseboards, trim, and wall obstacles
• Cable bend radius and connector clearance

For a tilt or swivel mount, check the TV’s final position—not just its position while flat against the wall. Movement can change cable clearance and the amount of space required around the screen.

Check the mount and wall separately

Correct M4, M6, or M8 screws secure the TV to the bracket. They do not determine whether the mount is safely attached to the wall.

Before installation, verify:

• The mount’s stated TV-size and weight range
• The TV’s actual weight without removable accessories
• The VESA range supported by the mount
• Whether the mount is fixed, tilting, or full-motion
• The wall construction and available structural attachment points
• The fasteners and installation method specified for that wall type
• Clearance for studs, masonry, electrical wiring, and plumbing

Do not treat drywall alone as a structural attachment surface unless the mount’s instructions specifically provide a suitable method. For stud-mounted installations, locate and use the required structural members. For masonry or other wall types, use the fastening method and hardware specified for that construction.

The wall fasteners and the TV-to-bracket screws are separate decisions. A correct M6 screw does not make an unsuitable wall anchor safe.

Final locking and alignment

Once the screw diameter, pitch, length, spacers, VESA alignment, and wall attachment method have been verified:

1. Support the TV and bracket throughout the attachment process.
2. Start every TV mounting screw by hand.
3. Keep the bracket aligned with the VESA inserts.
4. Tighten the screws gradually in an alternating pattern.
5. Stop at the torque or tightening guidance supplied by the manufacturer.
6. Do not use extra force to compensate for a poor fit.
7. Confirm that the TV is supported evenly and that no screw is bottoming out.
8. Engage any locking tabs, safety screws, or retention mechanisms required by the mount.
9. Test the mount’s tilt or swivel movement without pulling on the TV.
10. Recheck that cables are not under tension or sharply bent.

If the mount has a final locking screw or safety latch, it is part of the retention system—not an optional alignment adjustment. Follow the mount’s instructions for engaging it.

Common mistakes to avoid

• Choosing a screw by diameter while ignoring thread pitch
• Measuring the screw head instead of the threaded section
• Assuming all M6 or M8 screws have the same length
• Using a screw that bottoms out inside the TV
• Forcing a screw that does not start smoothly
• Omitting spacers required for a recessed or curved rear panel
• Adding unapproved spacers or washers to compensate for the wrong screw
• Confusing VESA dimensions with screw diameter
• Positioning the mount from the TV’s outer edge without checking VESA offset
• Ignoring cable clearance behind a tilting or full-motion mount
• Treating the TV-to-bracket screws as a substitute for proper wall fasteners

Installation checklist

TV and hardware

• [ ] The TV manual or manufacturer confirms the screw diameter.
• [ ] The thread pitch has been verified, not assumed.
• [ ] Screw length accounts for the bracket, washer, spacer, and required engagement.
• [ ] The screw starts smoothly by hand.
• [ ] No screw bottoms out or contacts the inside of the TV.
• [ ] The required washers and spacers are installed in the specified order.

Mount and position

• [ ] The mount supports the TV’s weight.
• [ ] The mount supports the TV’s VESA pattern.
• [ ] The TV’s VESA-hole offset has been considered.
• [ ] The screen center is planned at the intended height.
• [ ] Tilt, swivel, soundbar, furniture, and cable clearances have been checked.

Wall and final locking

• [ ] The wall construction has been identified.
• [ ] Structural attachment points and approved wall fasteners have been verified.
• [ ] The bracket is level and securely attached.
• [ ] TV mounting screws are tightened according to the instructions.
• [ ] Safety screws, locking tabs, or retention mechanisms are engaged.
• [ ] Cables have enough slack and are not being pinched.
• [ ] The mount moves only as intended and the TV remains secure.

If you are still unsure whether the insert requires M4, M6, or M8 hardware, pause before installation and confirm the TV’s documentation or contact the manufacturer. You can also browse TV mounts after confirming the TV’s VESA pattern, weight, wall type, and movement requirements.