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I’ve read somewhere that increasing the fittings and air hose size fr0m 3/8 to 1/2 will give your air tools more power/torque. My craftsman impact wrench says it has 700 lbs of torque… I don’t see it. I have 3/8 hose and fittings, would an increase in size make a difference? -Compressor 29 gal, air delivery: 5.9 CFM @ 90 PSI, 7.3 CFM @ 40 PSI. Any thoughts?
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In my experience, increasing the air hose size adds a little bit more air and power delivery, but nothing too noticeable. If you increase the fittings, ensure that the compressor can handle it and keep up, but in your case you have a 29 gallon, which should be fine.
Using fittings and hoses with a small internal diameter (some cheap fittings) certainly reduces the power of an air tool. Especially the curly hoses you get with a lot of compressors are bad, they’re pretty much for inflating tires and such. A straight hose and decent fittings in either size should be fine though. 🙂
I do have straight 25 foot 3/8″ hose (and fittings) but when Ive used the Impact wrench on axle nuts, crankshaft, exhaust etc… It doesn’t seem to have the power to remove them without prolonged and repeated contact and without using heat and/or penetrating oil. Well, I guess the only real test is to change over to a larger size and see what happens. I was just wondering what most mechanics used… if most use 3/8 with no problem, then perhaps my compressor is too small or under-powered or perhaps I need to upgrade my impact wrench. Thanks for your input it’s appreciated.
I just checked, all my stuff has 1/2″ fittings though, so maybe 3/8 indeed isn’t enough? Not sure.
I think there is already an ETCG video about the fittings..
Great video. Answers all my questions. I had tried YouTube previously but I didn’t know what to search for. -Thanks.
The longer and smaller the hose, the more pressure drop at the tool.
You likely have a single stage compressor that might have max air pressure of 125 PSI?
A dual stage compressor can produce over 175 PSI.I have an old single stage 5HP 60 gallon compressor. The outlet and outlet hose are 1/2″ and goes to a filter/regulator/oiler that are all 1/2″. the outlet of the oiler is a 1/2″ quick disconnect, but I have an adaptor to connect up the 3/8″ hose which is what I normally use.
I have a cheap impact that works OK, but dosen’t loosen really tight stuff, and then I have a nice Snap-On impact that works way better at the same air pressures, so the quality of the tools matters and also make sure to keep them oiled.My compressor is a belt driven 2hp cast iron single stage with a max of 150 psi. I think my craftsman impact would perform much better if I can verify that I’m supplying the needed 90 psi at the tool. I’m gong to try and find out how much loss I have and see if I can compensate (as per the video). I’ll post my results when I finish. -Thanks for your input.
Well here are my results so far:
With a 50 foot 3/8″ hose and 1/4″ fittings with static pressure of 90 psi at the tool (impact wrench)… the working pressure dropped to ~30 psi.
With a 50 foot 3/8″ hose and 3/8″ fittings with static pressure of 90 psi at the tool (impact wrench)… the working pressure dropped to ~65 psi.
So increasing just the fittings alone doubled my working pressure. In order to get a working pressure of 90 psi at the tool I had to change my static pressure to ~126 psi.
Next I will upgrade my air hose to 1/2 inch and post the results.Also some food for thought, some high flow 3/8 fittings will make a big difference as well. The internal port size is a major difference between cheap and the good fittings
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Just a quick food for thought . It probably makes a large difference as to how much air the tool uses . A small 3/8″ air ratchet & the smaller hose & fitting will probably fine .
But you were asking about a full size 1/2″ impact wrench .
For my DIY shade tree mechanicing , I use a Harbor Freight 1/2″ electric impact wrench . It is big & heavy & bulky & not too handy . But so far it has worked pretty well . And easier to string an extension cord . And I seem to remember it cost $ 40 – $ 50 .
If I had an easy way to get an air hosr to the front drive , I would use my ancient 1/2″ air impact . If it still works .
God bless
Wyr
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