Threaded tubing - source?

I need some externally threaded tubing to complete a custom-made lamp - about 1/4" or 3/8" diameter. Ideally to fit straight into a threaded bulb holder, but that's not essential. Brass for preference, steel would do.
Local electrical ships and wholesalers can't help in fact most didn't know what I was talking about. Anyone know of an online source?
I've already tried Specialist Lampfitting Supplies in Warrington who normally stock it, but they haven't any.
Geordie2
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
RA Oliver Lighting in Mochdre, Colwyn Bay, N. Wales.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.