Neil wrote in from the UK, asking about Panasonic’s EY7552 18V twin hammer impact wrench. I sent him a reply, but the email bounced back with an error message that his mailbox is unavailable.
I’m considering buying a Panasonic impact wrench for scaffolding work.
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Would this be suitable and what is the cost of the latest twin hammer version?
I wish I could answer this, but I have not tested the new Panasonic impact wrench firsthand, and I don’t know of anyone that has even seen one in person.
It *should* be suitable for scaffolding work, as it is said to have a pin through-hole socket retention mechanism. The impact should have more than enough torque, and so my main concern would be socket retention, as you don’t want sockets slipping off the anvil and falling onto other workers or passerby’s below.
The typical UK dealers I look at don’t carry this particular product, but one dealer I found online has the kit for £465.60 including VAT.
The new Panasonic EY7552 twin hammer impact wrench is currently available in the USA as well:
Buy Now: EY7552X Bare Tool ($275), EY7552LS2S Kit ($480) via Amazon
If you don’t absolutely need the Panasonic impact’s IP56 dust and water resistance, Milwaukee’s M18 FUEL brushless heavy duty impact is a very good alternative.
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I still have questions of my own about the twin hammer aspect of the new impact wrench, regarding how it achieves increased torque, reduced vibration, and lower noise. It seems counter intuitive that a double hammer design would be less noisier. I would think that two impacts at the same time would create more noise. I asked Panasonic about this months ago, but they never got back to me.
If anyone has experience with this particular model, please chime in with your impression of it!
Jerry
I can see the reduced vibration, and increased torque, because the twin hammer impacts I have seen have two hammers hitting the anvil from opposite sides at the same time. Like you, I can’t se how it would be quieter, unless there is an improved noise dampening system older tools did not have, and the reduced noise is due to that, rather than from simply having twin hammers.
joe
I would love to see the inside of how the twin hammer works.
Jon
Just like v-twin engines, router bits, and so many other areas, the twin hammer design should absolutely reduce vibration and increase the efficiency of the system, resulting in greater torque (much like two flute router bits make more efficient use of the power of the router, comparable in some situations to upgrading to a slightly more powerful router).
I really don’t mean for this to sound condescending, but I am aware of the potential when discussing this on such a fundamental level. My apologies if it seems rude.
Sound waves ARE vibrations. A vibrating/pulsating surface pushes air into sound waves, which in turn push your eardrum in basically the same pattern. Reduced vibrations within a system will inherently mean reduced sound waves, and therefore reduced sound levels.
But I suspect there is more to it than that. It is perfectly conceivable that two slightly smaller hammers would produce more torque and less noise. Without getting deep into some more complicated sound theory here, different size hammers will resonate at different tones, and different tones require different techniques for dampening. It is MUCH easier to dampen high pitched sounds than low pitched ones. (Consider how much of the tonal range you can hear from other cars, for instance.) And smaller hammers would produce higher tones than larger ones, all else being equal.
I don’t know that the hammers are smaller. I’m just sharing one plausible explanation. Also if I’m reading the correct pages, the new model spins a little slower than the old one, which results in fewer impacts per minute, which could also explain the decreased noise (and offset by the dual hammers to produce higher torque despite the slower speed).
Jon
I meant how much you can hear of the tonal range of the music playing in other cars.
Stuart
Yes, it’s perfectly conceivable that the twin hammer design could provide numerous advantages, but a lot of assumptions are dependent on the tool’s engineering.
In this case, there are too many uncertainties for me to work backwards using marketing claims to understand how the tool is designed. There is too much risk of me getting something wrong, which is why I’m still waiting on Panasonic to explain their marketing claims in greater detail.
There is no evidence that the impact’s hammers are smaller. The speed could be slower, the anvil shape and size factors could be different, materials could be different, and so forth.