G-Code from Fusion 360

I am dissecting some G-Code created from Fusion 360 with the ultimate goal of creating a quick way to do simple function, like route a line, or a circle or a set of holes. Nothing complicate, just I find that when in the shop I sometimes want to do something quick and easy and don’t want to load Fusion 360 and go through all the steps.

I think I understand the code, however I have one question on code at the top of the file.

Here is the block of code.

N25 S18000 M3
N30 G54
N35 G0 X0 Y0.15
N40 G43 Z1 H5
N45 G0 Z0.3

The S18000 sets the spindle speed (not important as I don’t have a spindle) (yet…)
G54 sets the fixture offset.
G0 X0 Y0.15 is a rapid move
G43 Z1 H5 - I know the G43 is a Tool Length Offset, however what is not clear is the H5 portion. How is the value set for H5, is this done on the controller, or is this another command that is there, but not really used.

Thanks

From my understanding,

H5 is a tool reference
However, OF does not keep track of a tool table, so H5 references nothing.
Z1 is the offset in this case.

G Codes (linuxcnc.org)