Todd,

That is likely nothing more than a #8 x 3/4" tapping screw.  If it has a sharp point it is a type "AB", if it has a blunt point than it is a type "B".  While it is possible that it has some sort of special thread, such as a proprietary thread for plastic, if it is going into metal, than it is not too likely.

There really aren't any metric spaced thread screw standards, so Europe just used imperial (inch) screws and gave them a metric call out.  Sometimes this causes problems, because one person may call the 4.2mm screw a 4mm diameter screw.  If it has a hex head, then the screw will have a metric hex head.  If it a phillips, then you need a metric Phillips screw driver, I'll sell you one for $50.00 ;)

4.2 / 25.4 = 0.165" (0.164 is nominla diameter for a #8)
19.0 / 25.4 = .748" (.750" = 3/4")

John Reynolds - Fastener Engineer

"in Etka, how do you dechipher the following:

tapping screw B 4,2 x 19"