Ok, I try to use other words to explain: Let´s first assume case A (which doesn´t reflect reality!): You buy a 3/8 Stihl RM chain, which has NO raker depth. So initially with a brand new chain the raker has the same height as the cutter. Then you can´t start off cutting with this chain, you have to define first your raker depth. So you can now manually file down the raker to a depth of 25 mil without using a gauge tool or whatever. This means you have now a chain as you can buy it. A brand new chain with a raker depth of 25 mil. Out of the cutters´s geometry this corresponds directly to a cutting angle of 6.3° with this Stihl chain. Now case B: you buy another time the already mentioned chain with NO raker depth. This time you don´t file the raker down manually to a depth of 25 mil, instead you use one of my raker depth gauges. What happens? Using gauge type 1 for the example of page 5, you get the same number of a raker depth of 25 mil. Because the gauge´s design variables (thickness and pivot length) were set by me in such a way, that the gauge tool starts with 25 mil at the 0 mil wearing point = new chain Type 2 is a different case: In this example with the 'initially NO raker depth' chain, my gauge type 2 would achieve a raker depth of 23.8 mil corresponding to a cutting angle of 6.0°. Now we change to reality: You can´t buy a chain with NO raker depth. The mentioned Stihl chain has ALREADY a raker depth of 25 mil and a cutting angle of 6.3° when you buy it. So back to the examples of page 5, in each case the values for the first three cutting angles you achieve in reality vs. what you would achieve when having a chain with NO raker depth: Stihl with type 1: 6.3, 6.5, 6,6 / 6.3, 6.5, 6.6 Stihl with type 2: 6.3, 6,4, 6,6 / 6.0, 6.4, 6.6 Carlton with type 1: 7.1, 7.0, 7.0 / 6.9, 7.0, 7.0 Carlton with type 2: 7.1, 6.0, 6.3 / 5.5, 6.0, 6.3 I hope this question is now answered with the numbers given directly above For type 1 the 7.1° is flowing with the rest, because I did set the gauge´s design parameters in such a way. As I already mentioned: This is not that easy with type 2 when assuming given steel material thicknesses. In these examples on page 5 I took common steel thicknesses of 39 mil and 47 mil (commonly available in Germany). So in this example my type 2 seems not to perform as perfect as it could. But: I can do the same thing here of course, as I have shown for the Stihl chain above on page 11, I aim for a gauge tool design parameter value as perfect as possible but now have the little problem of having to use a not common material thickness. For the Carlton lo pro chain this means now using a material thickness of 43 mil when aiming for the initial cutting angle of 7.1° and allowing a small overhead. Then we have the following distribution of numbers: Not bad I think BTW: The Carlton chain I use is type N1C-BL, meaning 3/8 low profile, 0.050" driving link gauge, semi chisel, bumper style. The initial cutting angle is 7.1° according to my measurements, and Carlton recommends a sharpening angle of 35° for this chain, so Carlton is more on the 'aggressive' path According to my numbers the start would be at 16.3 mil, so the first three numbers would be 4.1, 4.3, 4,5 degree instead of the 'real' 6.3, 4.8, 4.5 degree. The Husky gauge with hard setting used on Stihl does really mean HARD At least the first quarter delivers a little bit too high values of the cutting angles for my taste, but with the rest it would be a suitable 'really soft wood' setup. -------------------------- Nice seeing you getting deeper into the numbers, you seem to land in the 'zeal zone'