M5 M4 M3 Allen Wrench Hexagon Tool Quick Release Plate Screw Hex Key

Match the hex key size to the socket diameter of your fastener. M3 fits 3 mm hex sockets (common in electronics and small RC components), M4 fits 4 mm sockets (typical in furniture and bicycle hardware), and M5 fits 5 mm sockets (used in heavier mechanical assemblies and structural fasteners). When in doubt, measure the across-flats width of the socket recess before ordering.

The quick release plate screw refers to a design feature that allows the key to engage and disengage from the fastener socket more rapidly than a traditional fixed L-key. This is particularly useful when driving multiple fasteners in sequence, as it reduces the time spent repositioning the tool between turns.

This Allen wrench is designed for standard torque ranges appropriate to M3–M5 fasteners. For M3 screws, typical torque limits are 0.5–1.0 Nm; for M4, 1.2–2.5 Nm; for M5, 2.5–5.0 Nm. Exceeding these ranges with any hex key risks rounding the socket or damaging the key. For high-torque industrial applications, a T-handle or torque wrench with a hex bit is recommended.

Compatibility depends on the hardness of the key material relative to the fastener. For standard stainless steel socket screws (A2/A4 grade), a properly hardened hex key will perform correctly. Contact us to confirm material hardness specifications if you are working with Grade 12.9 or higher hardened fasteners.

Yes. M4 and M5 hex keys are the most common sizes used in flat-pack furniture assembly. The compact form factor of this key makes it easy to reach recessed bolt heads inside pre-drilled furniture panels. The quick release mechanism also speeds up repetitive tightening when assembling multiple identical joints.

Order 1 piece for a single repair or replacement. Choose 5 pieces if you maintain multiple toolkits across different locations or want spares on hand. The 10-piece pack is suited for workshop restocking, small production runs, or team environments where tools are shared and occasionally misplaced. Bulk packs offer a lower per-unit cost.

This listing features a standard flat-tip hex key profile. Ball-end or magnetic tip variants are not included. If your application requires angled engagement (typically up to 25–30° off-axis), a ball-end hex key would be more appropriate. Contact us to confirm if a ball-end version is available for your required size.