M2 Carbon Steel Screws: When to Use the 8mm Length
By Official Hobby Components Online Store | Buy Electronic Kits, Components, Boards, Shields, Modules | Published: 2026-10-30
Category: Tips & Care
M2 screws are tiny metric fasteners for small electronics and hobby assemblies. Learn when the 8mm length fits best and how to avoid stripping or misalignment.
Quick answer
Use M2 carbon steel 8mm screws when you need a secure hold through parts that are 4–6mm thick combined, and when the joint is inside a compact assembly where a longer screw would protrude or interfere.
Why length matters for M2 screws
M2 screws are metric fasteners with a 2mm thread diameter. They are common in electronics enclosures, PCB standoffs, camera mounts, and small robotics. The 8mm length is a middle-ground option: shorter than 10mm or 12mm, but longer than 5mm or 6mm.
The right length depends on the total thickness of the materials you are joining. If the screw is too short, it won't engage enough threads for a strong grip. If it's too long, it may poke out the back, scratch a surface, or bottom out before fully tightening.
Carbon steel gives these screws good strength for their size, but it is not stainless. In humid or corrosive environments, consider a plated or stainless alternative.
When 8mm is the right choice
An 8mm M2 screw works well when the combined thickness of the parts you are fastening is roughly 3–5mm. That leaves about 3–5mm of thread engagement inside a nut or threaded insert, which is enough for a solid hold in most hobby applications.
Typical uses include mounting a small PCB to a standoff, attaching a sensor bracket to an enclosure, or securing a camera module to a 3D-printed mount. If you are using a nut, the 8mm length gives you room for the nut plus a little extra thread.
If your parts are thinner than 2mm total, a 6mm screw is often cleaner. If they are thicker than 5mm, a 10mm or 12mm screw may be safer.
M2 8mm screw FAQ
- What is an M2 screw?
- M2 is a metric thread size with a 2mm nominal diameter. It is one of the smallest common machine screw sizes, used in compact electronics and hobby assemblies.
- How do I know if 8mm is long enough?
- Measure the total thickness of the parts you are joining. Add the thickness of any nut or threaded insert. If the screw reaches through and leaves at least 2–3 full threads of engagement, 8mm is likely sufficient. When in doubt, test-fit with a slightly longer screw first.
- When should I avoid 8mm M2 screws?
- Avoid 8mm when the combined thickness is under 2mm (a shorter screw is cleaner) or over 5mm (you need more thread engagement). Also avoid carbon steel in wet or corrosive environments. For outdoor or humid projects, choose stainless or coated screws.
- How tight should I turn an M2 screw?
- M2 screws are small and strip easily. Tighten until snug, then give a gentle quarter-turn. If you feel resistance, stop—overtightening can shear the head or damage the threads. Use a proper-sized hex or Phillips driver; never use pliers.
Product facts
- M2 Carbon Steel 8mm Screw (Pack of ten): These M2 carbon steel screws are 8mm in length and come in a pack of ten. A pack of ten gives you spares for small projects, and the 8mm length suits typical PCB and enclosure thicknesses without protruding.
M2 Carbon Steel 8mm Screw (Pack of ten)
