In article .com,
Matty F wrote:
What is the recommended way to hold threaded galvanised steel rod
in a vise so that the thread is not damaged? The rod needs to be
cut with a hacksaw. Actually it will be cut in a metal bandsaw,
but it's the same question as the bandsaw also has a vise.

Wind two nuts onto it. Use one nut as the guide
for the saw.

--
Tony Williams.