These posts match our galvanised steel field gates, although metal field gates can also be hung on timber posts.
Using the tubular posts is really easy as the latch and hinges are already fitted to the gate posts so it's just concrete in the posts and your done.
Normally use 4 1/2" posts, smaller gates 6' wide and under can be hung on 3 1/2" posts but larger gates need 4 1/2" diameter posts.
Choose the right slamming post to suit the style of your gate which will have either a spring bolt or 'D' Loop. All gate posts with an auto latch for the 'D' Loop can be padlocked.