Amal carb cutaway

From my notes -

Amal Slide Cutaways: a stamped number from 2 to 5 indicating the height of the cutaway on the inlet side of the slide.

slides are listed from 2 to 5 in 1/16″ increments. The #2 cutaway would be 1/8″. A #3 cutaway would be 3/16″.

#2      =   1/8″     (3.175mm)
#2.5   =   5/32″    (3.96875mm
#3      =   3/16″    (4.7625mm)
#3.5   =   7/32″    (5.55625mm)
#4      =   1/4″     (6.35mm)
#4.5   =   9/32"    (7.14mm)
#5      =   5/16"    (7.9375mm)

I think each increment is 1/32 

So a 3 1/2 slide is 1/32" different to a 3 and the increment is 1/16   ,     ?????. Sounds like gibberish . 

As an increment would be considered as an increment of 1. and therefore 1/16", then 0.5 is 1/32".
So all makes sense. Well to me anyway!

The angle changes because the slope starts at the same point along the base.  1/32" per 0.5 step.
Slides aren't cheap.  If you want to experiment, use an old jumble sale pot metal slide with a low number and increase it with a file.  When you are happy, buy a new anodised or chromed slide.

You set the slide upright on a board and measure the distance from the board to the centre of the bevelled cutaway edge.

So Sean. Slides are availiable in full and 1/2 increments  and the difference between slides is 1/32"  .  The difference between full increments IE  a 3 and a 4 slide is 1/16" .  All clear now?.

From the original post I thought Sean wanted to check the cutaway like Michael says so didn't want to confuse the situation with actual filing the shape. As David says be very careful, you can't put material back on. 

To clear the 1/16" issue, in Amal speak the increment is a 'whole' number i.e. 1, 2, 3, etc. So as Robert says it is 1/32 if the 0.5 steps are used, as Amal do supply. 

Sorry, I should have been clearer in my initial answer. (edit - looks like Robert is quicker at typing than me!)