Cleaving Tools generally use diamond tips and blades to cleave the fibres.
Certain mechanical cleaving tools use a diamond blade to make a wedge in the fibre and the twist the fibre to produce a clean break. The cleave angle should be perfectly 90 degrees.
The blade in the cleaver may have to be replaced after a certain number of splices. Most manufacturers provide replacement blades.
The cleave made is examined by the splicing machine prior to fusion