1. Head frame body should be smooth,
smooth, clear outline; no sharp edges, burrs and cracks and so on. 2. Pins nail tip should be sharp, no sharp, partial distortion and so on. 3. Cranial surgery holder surface color should be uniform, do matte oxidation,
with anti-corrosion, anti-aging. 4. The head pins should be flexible in the rotation of the skull mount without
any jamming. The hardness of the head nail by heat treatment is HRC40 ~ 48. 5. Relax the wrench, adjust the arm on the shaft should be able to rotate, no
stuck phenomenon. 6. Relax the locking wrench, skull mount can be rotated 360 °, after locking in
the 150N pressure under the action of the locking parts should be no loose
phenomenon. 7. The base unit length 500 mm±20mm, adjusting rod width 165 ~ 560mm, the maximum height of
headstock extension 850mm±50mm. 12. The head skull clamp is made of 2A12T4 aluminum alloy.