In metric fasteners, “M4” means the screw’s thread diameter is 4 millimeters. The most common pitch for M4 is 0.7 mm (often shown as M4-0.7), which describes the distance between threads. A typical listing looks like “M4 x 12,” meaning 4 mm diameter and 12 mm length.

• Diameter: 4 mm major thread diameter.
• Pitch: Usually 0.7 mm (check the item page to confirm).
• Length: Measured from under the head; countersunk heads are measured overall.
• Fits with: Matching M4 nuts, washers, and inserts using the same pitch.

You’ll also find M4 screws in materials like stainless steel, alloy steel, and nylon—choose based on strength and corrosion needs. Matching the size and pitch to your hardware can reduce cross-threading and help parts assemble smoothly.

M4 and 1/4-inch screws come from different sizing systems and aren’t interchangeable in most setups.

• Diameter: M4 is 4 mm (~0.157”), while 1/4” is ~6.35 mm.
• Threads: M4 uses metric pitch (commonly 0.7 mm). 1/4” uses inch thread series (e.g., 1/4-20, 1/4-28).
• Compatibility: Mixing systems can lead to poor engagement or stripped threads. Match screws with nuts, inserts, and tapped holes from the same system.

If you need an inch alternative, M6 is closer in diameter than M4, but it’s still not a direct substitute. For replacements, compare the original fastener or review the size and thread details on the product page to confirm the correct standard.

An M4 screw’s nominal diameter is 4 millimeters, which converts to about 0.157 inches—roughly between 5/32” and 3/16”.

• Quick reference: 4 mm ≈ 0.157” (about 5/32”).
• Length conversions: 10 mm ≈ 0.39”, 20 mm ≈ 0.79”.
• Clearance holes: Many projects use ~4.3–4.5 mm holes (≈11/64”–3/16”), but check your hardware specs.

Head shapes and drive types vary, so required hole sizes and tools can differ. Reviewing the detailed dimensions on the product page—or measuring with calipers—can help you choose the right length, matching nuts, and washers for a tidy, reliable fit.

TVs and monitors that use M4 VESA screws vary widely in required length. A practical approach is to measure your setup:

1. Stack thickness: Add the bracket + any spacer/washers + the TV’s threaded insert depth.
2. Target engagement: Aim for several full turns of thread engagement without bottoming out.
3. Fine-tune: If unsure, start shorter and add spacers or step up in small increments.

Manufacturers often specify length in the manual, which is helpful. On the item page, look for the M4 diameter plus length (e.g., M4 x 10 mm). Using spacers or washers from a mounting kit can help achieve a snug, non-damaging fit, but exact needs depend on your TV and bracket design.

Contents vary by listing. Some M4 packs are screws only, while others bundle matching nuts, washers, or spacers.

• Check the title/specs: Look for phrases like “with nuts,” “with washers,” or “set.”
• Match the pitch: If nuts aren’t included, choose M4-0.7 nuts for standard M4 machine screws.
• Quantity and length: Verify piece counts and the M4 x length you need.

Some assortments include multiple lengths to fit different material thicknesses. You can use filters to narrow by pack type and material, then choose Pickup or Delivery at checkout. Reviewing photos and the “What’s included” section can help ensure you have all the hardware for your project.