28.6 FORK CROWNS
Please read this helpful hint-
How to fit blades to a crown. Pinch first, grind second
All or al least most manufactures blades are built to the Continental Oval spec: 28mm x 20mm on the large dimension. Crown manufacturers also follow the same nominal 28x20mm dimensions.
There is a maunfacturing variance of +/- 0.2mm on these dimensions.
The easiest way to get good fit from a particular blade an crown pair is to first measure the blades and crown.
You are looking for the dimension of the blade cross section that is too long. it will be either the major or minor axis, but not both. The blades will be slightly adjusted with a hand vise to fit the crown.
If the major axis of the blade is too long, press the major axis slightly to adjust the dimensions to the crown major axis. If the minor axis is the one that is too long, lightly press it to accomplish the same outcome.
Normally this will slightly increase the blade minor axis dimension. The crown is usually too large so this adjusts the overall fit to be better in both axis'
This approach to fitting will make the dimensions much closer without damage to the crown sockets by taking more material out than is actually necessary.