Screw PH-Cross Slot M4x12 vs M4x6: Choosing the Right Length
By eitech Metallbaukasten | Published: 2026-11-01
Category: Comparisons
Compare eitech M4x12 and M4x6 PH-cross slot screws by grip length, plate stacking, and pack sizes. Learn which length to use and when to switch.
Quick answer
Choose the M4x12 when you are joining two or more plates or need extra thread engagement; choose the M4x6 when the joint is thin or space is tight. The M4x12 is the safer default for general eitech builds, while the M4x6 prevents over-tightening in shallow assemblies.
How grip length changes the joint
The M4x12 and M4x6 share the same PH-cross slot drive and M4 thread, so the driver and nut compatibility are identical. The difference is how much screw shank sits inside the joint. More length gives you more thread engagement through stacked plates, but it also leaves more screw protruding if the joint is thin.
In practice, the M4x12 suits joints where two or more eitech plates meet or where you want the screw to pass through a plate and into a nut or threaded bushing. The M4x6 suits single-plate or shallow connections where a longer screw would bottom out or stick out.
Where the M4x6 wins
The M4x6 is the better choice when you are fastening a single plate to a profile or when the screw head must sit close to the surface. Because less shank is exposed, there is less chance of the screw interfering with moving parts such as gears or axles nearby. It also keeps the finished model looking cleaner where the joint is visible.
The trade-off is that the M4x6 offers less thread engagement in thick stacks. If you use it where two plates overlap, you may find the nut only catches a few threads, which can loosen over time.
Pack sizes and spare-screw planning
The eitech Screw PH-cross slot M4x12 comes in 25, 50, and 100-piece packs, so you can match the quantity to how often you rebuild. A small pack is enough for a single model, while a larger pack makes sense if you regularly combine sets or keep a shared spare parts box.
The M4x6 is supplied as a separate product; check its available pack sizes before ordering so you do not end up with more short screws than your projects need. Buying both lengths in modest quantities is usually more practical than committing to a large pack of one size.
Trade-offs at a glance
- M4x12 for stacked plates: Use the M4x12 when two or more eitech plates overlap or when you need the screw to reach a nut through a thick joint. The extra length gives more thread engagement and a more secure hold. Check that the screw tip does not protrude into a moving part.
- M4x6 for shallow joints: Use the M4x6 when fastening a single plate or when the joint is thin enough that an M4x12 would stick out. The shorter shank keeps the assembly compact and reduces interference. Confirm the nut catches at least two full threads before tightening.
- Pack size trade-off: The M4x12 comes in 25, 50, and 100-piece packs; the M4x6 is sold separately. A larger pack lowers the per-screw cost but ties up budget if you mainly need the other length. Start with a 25-pack of each length if you are unsure which you use more.
Product facts
- Screw PH-cross slot M4x12: The eitech Screw PH-cross slot M4x12 is a cross-recessed screw offered in 25, 50, and 100-piece packs. You can choose a pack size that matches your build frequency and avoid leftover screws.
Screw PH-cross slot M4x12
Which length fits your build?
Best for
- Builders joining two or more eitech plates who need reliable thread engagement
- Anyone replacing missing screws in a model that uses thick stacked joints
- Hobbyists who want a general-purpose spare screw for mixed projects
Not for
- Very thin single-plate joints where a longer screw would protrude
- Tight spaces near gears or axles where extra length could cause interference
- Builders who only need a few short screws and do not want a large pack
