Quality determines both result and safety, so the numbers are non-negotiable.
- Shaft hardness ≥ 450 HV0.2 – tough enough to penetrate without buckling.
- Tip perfectly centred, free of burrs or hooks; after a standard “press-against rubber” test the piercing force must be ≤ 0.7 N to keep pain minimal.
- Ductility – no cracks, breaks or delamination after the specified coil test.
- Surface finish Ra ≤ 0.4 µm, mirror-smooth for effortless insertion.
- Handle bond – axial shift ≤ 3 mm under pull-out load.
Only needles that pass every figure on this list earn a place in the clinic.
