A bicromatized laminated steel spindle with trapezoidal thread that allows the opening and closing of the light of the interchangeable jaws in cemented steel.
| Type | Nº 0 | Nº 1 |
| Mordent Length | - | 86 mm |
| Maximum Aperture | 62 mm | 86 mm |
| Weight | 0,851 kg | 5,200 kg |
| Dimensions L x W x H | 140 x 100 x 50 mm | 280 x 170 x 75 mm |