ISO Standard pitch for M8 coarse is 1,25mm. Fine pitch is 0,75 mm.
M6 has a 1,0 mm pitch.
Nice Tutorial!

It is now 2022 perhaps things have changed som even though I am using SU2017 Make.
I used to draw involute gears by hand, tracing a profile from "geargenerator.com" at a large scale and using arcs with suitable radii for the various sections, pushing into appropriate thickness and 3D printing in PLA made eminently usable gears.
One 'bug' that I have seen with SPGears 1.4 on Windows is a klipping plane phenomenon that is baffling. Only at a limited zoom factor is the generated gear visible and neither Zoom All nor Zoom Selected manage to make the gear appear. Perspective or Parallel projection makes no difference.

Thanks I had not noticed the ">" which shows the version. All is good!

I get no confirmation that my installation of updates (through the Extension Manager) does anything.
Is this to be expected?
SU Make 2017

My suggestions for the English text describing the plugin options:

These are the Helix along curve plugin options:
You can set a value for the radius of the helix start and another for the end (these values can be positive or negative)
You can set the number of turns of the helix (this value can be a positive integer or a positive decimal)
Specify the number of line segments that make up each turn of the helix (this value can be a positive integer decimal)
Modify the start angle of the helix (the angle value should be given in degrees as an integer or decimal)
Set the level of "noise" (the value entered must be between 0 and 1), this will add a different random value to each turn radius of the helix. This random noise will be greater when the input value is closer to 1
You can choose from five different options for a parameter called "adherence to the curve", which defines whether the helical curve will strictly or smoothly. (smooth is recommended for best results).
The "Calculation mode" simply summarizes multiple internal parameters that would not be easily understood by users. Sometimes very steep curves can cause unwanted results, in these cases smoother curves or slightly different tests can be performed by varying the "calculation method" to find out which will give the best results for that particular curve. If you are not having problems, it is advisable to leave this value in recommended mode (C)
You can set the direction of rotation of the helix, i.e. rotation in the clockwise or counterclockwise direction
Helicoid will create with a curve or a circular tube.
If you choose to create a tube, you can set your ratio (the value entered must be a positive integer or a positive decimal).
You can specify the number of sides of the tube (which can be a minimum of 3 sides, this value must be a positive integer).

Now I will try to design a lamp with the plugin! If I can install it! there were no installation instructions so I do not know where to put the files extracted from the .zip...