Rattle gun - How much torque is enough?

[Shounak]

I've got a 2.5hp compressor with a 40 litre tank and I previously had a 1/2" drive rattle gun with 230ft-lb of torque.

That was barely enough to get the standard wheel nuts of a Commodore and couldn't even begin to get the wheel nuts of my 19" rims, or any of my other cars (with rims).

YouTube - Rattle gun not working

Above is what would happen when I tried. Now I'm going to be taking off some heavily stuck bolts on my new project car and willl need a rattle gun to keep up.

I've found that the 3/4" drive rattle guns only have sockets starting from the 24mm mark, which for normal bolt on stuff on a car, is a bit too much. These rattle guns have a little more than 500ft-lb of torque.

I need something that will comfortably undo most things on a rusty old Ford and my car. Any idea what a decent amount of torque would be and how it would go with my compressor?

[immortality]

have a look at the airpressure in the tank as you press the trigger on the ratle gun, you'll find it drops to less then 80psi as soon as you squeeze the trigger then the problem is the compressor isn't big enough to supply the required volume at the right pressure to make the rattle gun produce enough torque to undo the bolts.

there is also an adjustment on the rattle gun to control output (asuming it's from supercheap seeing as it's yellow) numbered 1-4, can't remember which setting is for the greatest torque output.

at work we use a huge compressor setup that piped around the building in 2.5" pipe with 2 x 800ltr tanks (one for each building), the system sits at 110-120psi and never drops much bellow that, we use the 1/2" rattle gun to undo some bloody big bolts

[muttley383]

The quality of the rattle gun plays a big role. The cheaper units waste a lot of air and the more expensive units are able to supply more torque

[Hillerus]

I've got a 2.5hp compressor with a 40 litre tank and I previously had a 1/2" drive rattle gun with 230ft-lb of torque.

That was barely enough to get the standard wheel nuts of a Commodore and couldn't even begin to get the wheel nuts of my 19" rims, or any of my other cars (with rims).

YouTube - Rattle gun not working

Above is what would happen when I tried. Now I'm going to be taking off some heavily stuck bolts on my new project car and willl need a rattle gun to keep up.

I've found that the 3/4" drive rattle guns only have sockets starting from the 24mm mark, which for normal bolt on stuff on a car, is a bit too much. These rattle guns have a little more than 500ft-lb of torque.

I need something that will comfortably undo most things on a rusty old Ford and my car. Any idea what a decent amount of torque would be and how it would go with my compressor?

Have you considered a battery Rattle Gun? I use one at home, gets my wheel nuts on and off just fine. I also do a lot of field work, with no access to a compressor, and this thing works fine. I do sometimes need to crack bolts by hand first (such as truck spider hub wheel nuts). It will never be as good as an air one, but it was never designed to be anyway

You can get adapters that go from 3/4 to 1/2, allowing 1/2 sockets to be used on a 3/4 gun, but you really shouldnt need a 3/4 gun on a car anyway. I bought an SP Air rattle gun that I use for work, and it can undo most stuff a 3/4 gun can do anyway.

[Cheap6]

Re. torque requirement: Ask "What is the tightest bolt that you will have undo?" and work back from there, with a margin for any thread locking compound or corrosion. (230 ft.lb is about 170Nm). There will be torque vs speed at specified air pressure curves for the air guns.

If the compressor can't keep up and the duty cycle is low (as it will be for home use) an extra air tank will be cheaper than a new compressor and they are widely available, even from hardware stores.

[Shounak]

I just got hold of a mates 550ft-lb rattle gun with a 3/4" drive and decided to give my wheel nuts a shot with that one. Same problem. It just keeps rattling away and won't take them off.

So I put it to the test and decided to grip on to the socket and adapter. I had the rattle gun set to full speed and I was easily able to hold onto 550ft-lb of torque. Is there something wrong with my air compressor? Not enough air or power maybe?

All the auto shops assured me that 2.5hp and 40 litres would be more than enough for home rattle gun use. Btw, I don't think it's that my wheel nuts are too tight, because the tyre place that fitted and removed them a few days ago had no problems.

Any ideas?

[f1tzy]

Have you considered a battery Rattle Gun? I use one at home, gets my wheel nuts on and off just fine. I also do a lot of field work, with no access to a compressor, and this thing works fine. I do sometimes need to crack bolts by hand first (such as truck spider hub wheel nuts). It will never be as good as an air one, but it was never designed to be anyway

You can get adapters that go from 3/4 to 1/2, allowing 1/2 sockets to be used on a 3/4 gun, but you really shouldnt need a 3/4 gun on a car anyway. I bought an SP Air rattle gun that I use for work, and it can undo most stuff a 3/4 gun can do anyway.

sorry for this mini hijack but what attachment do you use for your battery rattle gun to accept sockets

[commsirac]

Btw, I don't think it's that my wheel nuts are too tight, because the tyre place that fitted and removed them a few days ago had no problems.

Any ideas?

Possibly the wheel nuts are too tight. Every commerical rattle gun thats ever been used on my car does the wheel nuts up too tight. Torque specs for a commodore are 100-125Nm. They obviously have high torque guns to get anything off, but dont change the settings when they put the nuts back on again. I always retorque the nuts after and typically need my 70cm long pipe over the wheel brace to get um undone.

[centy]

ok there is a 1000ft lb rattle gun for sale for $299 on the net.
Some times you need to break the nuts first.
I had a truck that the tyre shop could not rattle the nuts off so out the the breaker bar and crack them, then rattle off.
now try holding the rattle gun tight when you use it.
Maybe the flex in your wrist is allowing it to spring back between hammer blows.
Also tighten the bolts around the back og the rattle gun.

[delcowizzid]

its just your stupid little compressor they are nowhere upto the task like immortality said i had lone of a 2.5 hp direct drive compressor total *^%# need at least 12 cfm really and you find the slide shut fittings coming out of the compressor dont have a big enough hole down them .a short 2metre hose sometimes can help.or attach the hose to the rattle gun straight from the tank if there is a thread with a bung in the end of the tank.

[HoZy]

did either one of your 2 F U C K HEADS REALIZE!

This thread is a year old......

[delcowizzid]

hey wow so it is I blame centy LOL

[darrenp]

Guys , I realise this thread is over a year old though I felt the need to throw a couple of comments in for those reading it and wondering about their own air tool issues. A little background first I have been involved in the tools and equipment industry for over 25 years including 12 years with Snap on tools. I can tell you categorically that the main killer of performance to a rattle gun is airflow. This is the constant pressure available whilst the air is flowing through the line. Not so much static air pressure in the tank as most compressors will generate 120psi at full tank status. An air tool is simply an air motor and your input air lines capacity to maintain at least 90 PSI is nearly always your power culprit. We used to demonstrate this with a flow pressure gauge setup in line with a couple of different common air fitting such as ryco, jaymec and Nitto hyflos. The ryco is one the most popular with a median loss of about 35% as they are a cheap brass thing and just about every workshop has or has had them at some time. The jaymec’s are just an awful product and knee-jerk design reaction to the old problem of the balls falling out of the Ryco’s when you drive over them and have about 60% flow loss. The Nitto as you have probably guessed is the best of these with around 15% flow loss and provide a 120 PSI tank state with around 95 PSI flow rate. The other two I mentioned will restrict airflow by the percentages described and exponentially drop the tools available power by as much as the percentages and typically more depending on the load state. The ideal flow pressure is between 90-110 PSI for air tool performance and will ensure you actually get the rating that came with the tools. Rattle guns are a prime example of this effect and possibly the main tool that is affected by this loss. The bottom line is make sure you have the largest flowing air fittings you can get typically, Nitto style hi flows or the Cejn (Swedish made) product actually called hy-Flow though they are not case hardened like the nitto style which is why I prefer them over the Cejn. One last tip..don’t oil before use. Oil after and make sure you give it a decent squirt and then pull the trigger for around 2 seconds. this will displace all of your water that has accumulated inside you tool and will prevent your bearings and components from rusting while it sits in your tool box...for the record, that’s the number one reason air tools die...water in the tool that is a naturally occurring feature of every tank of compressed air. There is no away around this including air water separators with filters as small as .05 micron (spray painters standard). Draining the tank wont help either as that only deals with the tank water that was there before you begin to use it.. Again,...you must lubricate after use...then put away full of oil. I sincerely hope that is of use to some here..Phew!!…so much for a brief comment!

[wraith]

Holy lack of punctuation batman!

[Pub247]

lol im not even going to try and read that and nice dig aswell this thread is like a zombie

[kniever]

i read it but geez it was hard, make paragraphs mate, makes it a hell of alot easier to read

[Andrew426]

Guys , I realise this thread is over a year old though I felt the need to throw a couple of comments in for those reading it and wondering about their own air tool issues. A little background first I have been involved in the tools and equipment industry for over 25 years including 12 years with Snap on tools. I can tell you categorically that the main killer of performance to a rattle gun is airflow. This is the constant pressure available whilst the air is flowing through the line. Not so much static air pressure in the tank as most compressors will generate 120psi at full tank status. An air tool is simply an air motor and your input air lines capacity to maintain at least 90 PSI is nearly always your power culprit. We used to demonstrate this with a flow pressure gauge setup in line with a couple of different common air fitting such as ryco, jaymec and Nitto hyflos. The ryco is one the most popular with a median loss of about 35% as they are a cheap brass thing and just about every workshop has or has had them at some time. The jaymec’s are just an awful product and knee-jerk design reaction to the old problem of the balls falling out of the Ryco’s when you drive over them and have about 60% flow loss. The Nitto as you have probably guessed is the best of these with around 15% flow loss and provide a 120 PSI tank state with around 95 PSI flow rate. The other two I mentioned will restrict airflow by the percentages described and exponentially drop the tools available power by as much as the percentages and typically more depending on the load state. The ideal flow pressure is between 90-110 PSI for air tool performance and will ensure you actually get the rating that came with the tools. Rattle guns are a prime example of this effect and possibly the main tool that is affected by this loss. The bottom line is make sure you have the largest flowing air fittings you can get typically, Nitto style hi flows or the Cejn (Swedish made) product actually called hy-Flow though they are not case hardened like the nitto style which is why I prefer them over the Cejn. One last tip..don’t oil before use. Oil after and make sure you give it a decent squirt and then pull the trigger for around 2 seconds. this will displace all of your water that has accumulated inside you tool and will prevent your bearings and components from rusting while it sits in your tool box...for the record, that’s the number one reason air tools die...water in the tool that is a naturally occurring feature of every tank of compressed air. There is no away around this including air water separators with filters as small as .05 micron (spray painters standard). Draining the tank wont help either as that only deals with the tank water that was there before you begin to use it.. Again,...you must lubricate after use...then put away full of oil. I sincerely hope that is of use to some here..Phew!!…so much for a brief comment!

Good info, thanks for contributing.

Ignore those guys who will whinge about spelling and punctuation before offering anything constructive, Its pretty typical of these forums.

[Brett_jjj]

Theres nothing wrong with the punctuation or layout in that post,its just like any other post on here,if you seriously have trouble reading or understanding that ,then you better go back to primary school,jeez.It amazes me how many people on here have a go at someone over something so trivial.

[acarmody]

Cheers for the info mate. I have only used my new air tools twice but both times I oiled before working, so I'll remember to oil afterward for the next time.

[fonzo]

Dads a builder on the back of his ute has a decent size air compressor. nothing overly special. for my line of work i dont need air compressor so i brought a 24l 2.5hp unit. 2.5hp unit simply cant keep up. plug it into dads compressor and if the nuts ceased...i break my snap on impact socket.