headbolt q

[rocco16 at sbcglobal.net (Larry Fry)]

Generally, undercut means the radius between the head and the shank is
"internal", rather than "external".  (don't know how else to explain it...)
This will prevent the interference that an "external" radius would have with
a precision washer.  Personally, I'd rather use the standard bolt with a
clearanced washer.
Just personal preference.
Larry
sandiego16v

> ARP seems to make standard headbolts and "undercut" headbolts.  The
> undercut ones sell for a bit more.
>
> What's the difference?
>
> TIA,
> koabi