I served my SJIB Craft apprenticeship in 1981 in Scotland, and it was standard practice both on site and taught at college that a lock ring fitted on every conduit thread no matter what, you just never had a thread that then went on to normal smooth conduit tube. So when you bought a bundle of tubing it came threaded both ends half a coupling length, so we had to use the dies to create another few threads to cover the thickness of the locknut.

We never questioned it, so when coupling applied and a star washer into box and brass bush tightened up, the lockring was then tightened down onto the end of the coupling.

Everyone did that, and contractors. That said many a poor electrical contractor south of the border got caught out when doing conduit work in Scotland as they didnt put lockrings on, but once the clerk of works, electrical consultant or client rep so that, it was condemned and lockrings had to be fitted. Lotsof clients had it in their specs.

But mind the conduit was the earth/CPC, we run thru a red and a black conductor and that was it, CPC lead into socket top just came from the grub screw on back box or conduit box, no need to run CPC conductors thru the conduit.

What you did do before installing cables wasa high current conduit test, so tester applied, switch on and if there were any loose brass bushes/couplings etc, you heard the conduit "Singing", you located that noise, tightened the loose item and that was it.

When I travel about now, must admit conduit without lockrings seams to be the norm.

Trip down memory lane for me writing this post.

Cheers GTB

I served my SJIB Craft apprenticeship in 1981 in Scotland, and it was standard practice both on site and taught at college that a lock ring fitted on every conduit thread no matter what, you just never had a thread that then went on to normal smooth conduit tube. So when you bought a bundle of tubing it came threaded both ends half a coupling length, so we had to use the dies to create another few threads to cover the thickness of the locknut.

We never questioned it, so when coupling applied and a star washer into box and brass bush tightened up, the lockring was then tightened down onto the end of the coupling.

Everyone did that, and contractors. That said many a poor electrical contractor south of the border got caught out when doing conduit work in Scotland as they didnt put lockrings on, but once the clerk of works, electrical consultant or client rep so that, it was condemned and lockrings had to be fitted. Lotsof clients had it in their specs.

But mind the conduit was the earth/CPC, we run thru a red and a black conductor and that was it, CPC lead into socket top just came from the grub screw on back box or conduit box, no need to run CPC conductors thru the conduit.

What you did do before installing cables wasa high current conduit test, so tester applied, switch on and if there were any loose brass bushes/couplings etc, you heard the conduit "Singing", you located that noise, tightened the loose item and that was it.

When I travel about now, must admit conduit without lockrings seams to be the norm.

Trip down memory lane for me writing this post.

Cheers GTB