There are a multiplicity of different types of crimp, but in this case I am referring to the ubiquitous variety with a red, blue, or yellow coloured plastic sleeve denoting the wire size they are ...

(Credit: Matt Millman) While the resulting crimp is acceptable, it does crush the insulation when using AWG 24 (0.205 mm 2) wire, and with AWG 28 (0.0810 mm 2) wire the insulation is crimped fine ...