I just installed a couple of #8 switches from Signature Switch, and they are excellent products!
Just to be clear about switches: the Number of a switch, which is the number of the frog, (No. 8, No. 10, etc.) does not state "the ratio of the degrees of frog angle."
The number designation of the switch (or frog) states the rate of divergence of the two tracks. In a No. 8 switch, the rails diverge at a rate of 1 in 8 when measured from the "theoretical" point, as described below in the following quotation from "Railway Track and Structures Cyclopedia (Simmons-Boardman 1955, p. 378).
"The number of a frog is one-half the co-tangent of one-half the frog angle, or the ratio of the spread at any point to the length of a bisecting line between that point and the theoretical point of a frog." The theoretical point of a frog is defined as follows: "The theoretical point of a frog is the intersection of the gage lines of the frog." The "actual" rather than "theoretical" point of the frog is the point where the spread between the two gage lines is 1/2 inch.
