My 1st air impact - go with 3/8" or 1/2" drive ?

[djb]

Originally Posted By: CT8
What is the cfm of the compressor? If your compressor doesn't have enough CFM for the wrench the impact will not work properly.


The CFM of the compressor has nothing to do with it.

An impact wrench requires brief bursts of high flow. That requires fittings and hoses that will flow without dropping the pressure too much. Even a 3 gallon tank with a tiny compressor will work if it has good fittings, although you'll generally need over 125 PSI tank pressure to run an impact at 90 psi.

Generally people get their first impact wrench to be able to remove difficult fasteners. That argues for a 1/2" impact gun with the highest impact torque. Only after they have that capability do they want speed, comfort and convenience, which generally comes with a 3/8" battery powered impact.

 

[Excel]

1/2 Drive,I recommend Ingeroll Rand

 

[another Todd]

Originally Posted By: djb
Originally Posted By: CT8
What is the cfm of the compressor? If your compressor doesn't have enough CFM for the wrench the impact will not work properly.


The CFM of the compressor has nothing to do with it.

An impact wrench requires brief bursts of high flow. That requires fittings and hoses that will flow without dropping the pressure too much. Even a 3 gallon tank with a tiny compressor will work if it has good fittings, although you'll generally need over 125 PSI tank pressure to run an impact at 90 psi.

Generally people get their first impact wrench to be able to remove difficult fasteners. That argues for a 1/2" impact gun with the highest impact torque. Only after they have that capability do they want speed, comfort and convenience, which generally comes with a 3/8" battery powered impact.


True, tank size, pressure, and hoses etc are more important. My 3/4" IR impact is no more powerful than my 1/2" IR impact on a 3/8" hose. But when I put the 3/4" impact on a 1/2" hose it turns into a bolt busting beast. 3/8" hose is plenty for a 3/8" or 1/2" impact though.

 

[Piston_slap]

Don't use adapters for drive sizes. Get a full set of impact rated sockets (6 point, chrome moly) to cover the entire size range expected (7/16-1.0")

 

[Merkava_4]

Can you take a harmonic balancer bolt off with your 3/8 impact ?

 

[robshelton]

Spend some money on a good high quality 1/2" impact and you will never regret it. Then get a less expensive (Cheap) 3/8" impact to use on smaller and hard to get to fasteners. The Harbor freight impact sockets are inexpensive and plenty good for non-professional use. Actually I've seen several techs using them in dealerships around here. May have something to do with the local store being 2 miles down the road. 3/8 flex impact sockets can and will be your best friend so I'd highly recommend another purchase from HF or Northern Hydraulics. You will probably need and end up with at least 4 sets of impact sockets. 1/2" and 3/8" in both regular and flex. Watch for sales and discount coupons! Try to avoid the temptation to use chromed sockets on impact wrenches. I've seldom heard of them "Shattering" but have seen several crack open and the chrome start to flake off. When it does, the chrome is nearly as sharp as a razor.

 

[another Todd]

Originally Posted By: Merkava_4
Can you take a harmonic balancer bolt off with your 3/8 impact ?


Never tried, but I doubt it. The 1/2" will for sure if it is a quality gun (I have mostly IR for air tools)

 

[The_Eric]

Originally Posted By: Merkava_4
Can you take a harmonic balancer bolt off with your 3/8 impact ?


My 3/8" Snap-On MG325 will take off basically any crank bolt or lug nut that comes into the shop, along with suspension bolts too.

It's only on rare occasions that I need to use my 1/2" gun. After that I reach for THIS MONSTER

 

[sciphi]

Again, whatever impact is purchased, upgrade the fittings on a home compressor to high-flow. My free bargain-basement impact struggled to budge lug nuts torqued to 80 ft/lbs at first, even with my 30 gallon compressor cranked to 130 PSI to get ~90-100 PSI at the tool. That was entirely due to the restrictive fittings on my compressor and hose. Upgrading to high-flow fittings (Milton V-style in my case) lets it easily remove lugs now, even with ~70 PSI at the tool. The impact is getting the volume of air it needs to work.

For home use on a smaller compressor, those high-flow fittings make the best use of every bit of air. Well worth the fairly minimal expense.

 

[demarpaint]

Originally Posted By: sciphi
Again, whatever impact is purchased, upgrade the fittings on a home compressor to high-flow. My free bargain-basement impact struggled to budge lug nuts torqued to 80 ft/lbs at first, even with my 30 gallon compressor cranked to 130 PSI to get ~90-100 PSI at the tool. That was entirely due to the restrictive fittings on my compressor and hose. Upgrading to high-flow fittings (Milton V-style in my case) lets it easily remove lugs now, even with ~70 PSI at the tool. The impact is getting the volume of air it needs to work.

For home use on a smaller compressor, those high-flow fittings make the best use of every bit of air. Well worth the fairly minimal expense.


Those Milton fittings are well worth the money!