thanks mate 15mm might be pushing it for me, I only have 1/2" outlet on the compressor (actually its a bung that im going to remove) so it seems a little pointless to use 15mm hose when the regulator and fittings only go to 12mm.
Or am I missing something?
Just because a restriction is in place smaller than the bore of the hose doesn't limit the effective bore size to that of the restriction.
A larger bore hose will flow more air than a smaller hose even if they both have a small diameter fitting on the end. In fact, the majority of airline fittings are smaller than 3/8 or 1/2, but there are still benefits to uprating the hose.
If you are using the common 'pcl type' couplers I suggest ditching them in favour of something (anything!) else. I use Euro type and there is a difference.
Cheap air tools use a lot more air than good ones, so if you are using cheapish impact wrenches etc you may see a lot of benefit to upgrades.
How long the hose is should be taken into account. If it's only say 5 meters then there's little gain in going massive, 10mm (3/8) ought to suffice. But if it's 15m long it's worth going bigger.
Bear in mind the downside of going bigger is an increase in weight and a decrease in flexibility. You may want to consider using whip hoses on the tools, I fit swivels too which really make a big difference. About £2.50 each from China on eBay.
I see, thanks, what's up with the pcl connectors like? I've just ditched all euro? (little stubby ones) to fit pcl as the connectors always fill with crap and leak. I thought the pcl looked a little more rugged as the seal is a lot further inside
well god knows what i had before that but the bores in the pcl connections look a bit bigger. I am going to use 15mm hose which i thought was 5/16 but isn't, I think its about 10/16 as its over 1/2"...
I reckon the male parts of the connectors should be about even aslong as they have a similar bore, I bet its the couplings that make a difference as some of the cheap ones I've had in past have really held back thing.
ill get a couple of pcl xf bits to compare them I think
Put a PCL male into a female and blow through them, then do the same with a Euro set and you'll see the difference.
As to leakage, buy decent ones! I avoid anything other than genuine PCL (the make) where possible for all types as others don't tend to last long. Getting what you pay for and all that.