Why some cable cutters mention Max diameter specification and others Max mm2 ?

[Kiriakos GR]

I found a new puzzle to solve mostly for helping others.
This is about cable cutters and even automatic wire strippers, and about their offered as Maximum wire or cable supported specification.
And the all idea this a good understanding of what is mm2 VS diameter in mm. 

As first example, I will use my new self-adjusting wire stripper / cutter.
Stripper specification:
Works on the single or multi-stranded cross-section 0.2-6.0mm² (24-10 AWG) cables.
Cutter specification:
Integrated lever-action cutter makes a clean cut for maximum 4.0mm² cables.

While I am a professional electrician, my specialization this is maintenance, and the difference between me and an installer electrician, this is that the installer electrician he is obligated to perform constantly mm2 to mm calculations for wire sizing, and I am not.

Long story in sort, Max supported wire at my new wire stripper this referred as 6.0mm² this is not equal to 6mm diameter.
An 6mm2 stranded wire, this is calculated according its strand diameter due a mathematical calculation.
Actual physical diameter of conductors will be approximately 3.06 mm, and with it insulation the diameter will increase to approximately 4.66 mm.     
And therefore if I am up to protect this tool from having a premature failure, I must to obey or follow the manufacturer recommendation to the letter.

As second example I will mention light duty cable cutters (pair of flat cutting jaws), these mention supporting diameter of 10mm or up to 16mm.
This case it is different, one cable sheath this can be the host of many wires or of a solid wire or stranded.
Solid wire its harder to cut than a stranded one, the stranded has air gaps inside.
Also a cable with many wires inside this is much more easy to cut, because there is inside a larger portion of soft insulation and lesser portion of actual copper.
Here the manufacturer specification of Max mm supported diameter its more easy to be understand.

Even so, there is a problem with the no-name cutters, most uneducated Chinese sellers advertise Max jaws opening as this be the Max supported cutting diameter. 
I was had to inspect ten product listings, so to discover that an 22mm advertised of Max opening cable cutter this actually supports 16mm Max diameter at cutting a cable.

As third example I will mention the micro cutters, 1mm diameter of copper wire, this translates to approximately 1.2mm of insulated wire.

In conclusion: Be cautious when a manufacturer delivers mm2 as supported specification for stripping or cutting.
Because actual supported wire diameter at the metric system, this will be a much smaller number.
     
In the occasion that I will buy my economy light duty cable cutter (16mm Max), I will have to stick at my planing that I will never use it to cut anything over 5x6mm  (17mm diameter) European PVC cable.

Regarding my new high precision automatic stripper and cutter, I will be at the safe side, by always measuring first the wire diameter that I am going to work with.