Rivet gun what do the sizes actually mean?

[GS_C152]

Hi I was hoping someone might be able to explain the difference between 2X, 3X, 4X etc. rivet guns.

I have been looking at various sites and manufacturers and like the look of atlas copco. A bit on the expensive side I know but I have previously used some of their other tools in my past employment and know I'm paying for quality.

I've been looking at their different 3x rivet guns and have found two that are massively different and is making me question what the references "2X" "3X" "4X" and so on actually mean?

One 3x rivet gun I'm looking at has 2160 blows per minute at 6j on energy per blow while another 1920 bpm at 3j per blow. My initial thought was that blows per minute and energy per blow were what led to the designation of "3X" or maybe it was total energy transfer per minute (bpm x energy per blow) but both of those don't seem to be the case, and I know atlascopco have been around for years so it's not even like they're a no-name Chinese brand just saying "oh yeah these are definitely for aviation" and just slap whatever labels on them they feel like.

Google says it's something to do with the power and size of rivet it can drive, but surely a 3/16th rivet (or whatever size) would need the same amount of energy to drive?

So could someone please explain this to me as I feel like I'm being a total idiot...

The guns in question:

RRN 18P | Atlas Copco US

RRN 18P

www.atlascopco.com

RRH06P | Atlas Copco US

RRH06P

www.atlascopco.com

Thanks!

 

[Salty]

Unless you're building wing spars or something beefy like that, a 2x is all you need. JMO

 

[tsts4]

The smaller the number the lighter and faster the gun hits. For 3/32 (AD3) and 1/8 (AD4) rivets, both 2x and 3x are fine. Unless you need to set spar rivets or some other larger sized rivets, a 4x would potentially be more problematic and lead to smilies, creases, and dings. I built my plane with a 3x and would do so again.

 

[Bell206]

is making me question what the references "2X" "3X" "4X" and so on actually mean?

In general, the "x" is an industry designation that equates to the piston size and stroke of the rivet gun. You need to select the proper gun based on what riveting tasks you are performing. For an all-around rivet gun the 3x size covers 99% of what you will encounter on most Part 91 aircraft. If this is your 1st venture into sheetmetal work, then I would highly recommend looking into 3x rivet gun kits from Aircraft Tool Supply (ATS) or the Yard Store. Refurbished Sioux or Cleco brand guns are also very good deals on occasion that gives you a quality top-shelf gun at a reasonable price.

 

[Warmi]

I have been using 3x for everything ( 3/32, 1/8 and 5/32 ) - just recently got 4x to handle about 2 dozen longish 3/16 rivets in the spar attachments ..so unless you are doing anything like that, 3x will be more than enough.

3x would just not handle 3/16 past certain length - no matter pressure settings , it just did not have enough force to set these large rivets.

 

[Craig]

When I was on the production side of work, we'd use 2x's, 3x's and 4x's along with a 9x for a few things... Weren't a lot of guys that could hold the 25# bucking bar steady for very long when we were shooting with the 9x.

 

[nauga]

I set every -3 (3/32") rivet on my RV-4 with a 2x gun or hand squeezer, and every and -4 (1/8") rivet with the same 2x gun. Knowing what I know now I'd get a 3x gun, mostly for convenience. I set the -6 (3/16") spar rivets with a "sort of arbor press" and hammer (per plans at the time), and would beg, borrow, or steal a pneumatic squeezer if I had to do it again.

Nauga,
hammered

 

[Bell206]

And just to add, the issue with using too small a rivet gun is you can under expand and potentially work harden the rivet bucktail due to the additional strikes needed to obtain the proper bucktail. Both of which can lead to other problems. But another tip is to also select the correct bucking bar as well as I tend to believe the bucking bar can have a greater influence on the final rivet set than the difference between a 2x vs 3x in most cases.

 

[TCABM]

….pneumatic squeezer…

That’s tool #1 to for me to buy unless I decide on a Sling TSI. Why make life harder than it needs to be?

 

[tsts4]

That’s tool #1 to for me to buy unless I decide on a Sling TSI. Why make life harder than it needs to be?

Concur. My SOP was to only buck rivets that I couldn’t squeeze with my pneumatic or manual (Cleaveland Tools Main Squeeze). Helps to have a variety of yokes (I had the standard 3”, a longeron, and a 4” no-hole).

 

[Jim K]

Concur. My SOP was to only buck rivets that I couldn’t squeeze with my pneumatic or manual (Cleaveland Tools Main Squeeze). Helps to have a variety of yokes (I had the standard 3”, a longeron, and a 4” no-hole).

I actually picked up a second pneumatic squeezer at osh at the aeromart. An old CP. I like it better than the new one I bought from ats when I started, it came with a 4" yoke, and now i don't have to switch dies so much. I need to get a couple more countersink cages.

Back to the op....I didn't look that deeply into the specs. Van's recommended a 3x, and I got a used "red box" set from the yardstore. It's fine so far as I can tell. It drives rivets and has good trigger control. It is kind of amazing two "3x" guns would have almost double the power of the other. The 3x is almost too much for the 3/16 rivets that I'm driving thousands of. A 2x might be better, but i think the 3x is necessary for the 1/8. Regulating the pressure up & down fine tunes the power. I run 40-60psi for 3/16 and about 80 for 1/8. Ymmv.

Get a little tungsten bucking bar. Mine's like 3/4x1x4 or so and has bucked 95% of the rivets. I do occasionally need one of the goofy shaped steel ones that came in the kit.

 

[NordicDave]

I have been using 3x for everything ( 3/32, 1/8 and 5/32 ) - just recently got 4x to handle about 2 dozen longish 3/16 rivets in the spar attachments ..so unless you are doing anything like that, 3x will be more than enough.

3x would just not handle 3/16 past certain length - no matter pressure settings , it just did not have enough force to set these large rivets.

This is correct. If you are buying one gun, the most common rivets are #3, #4, #5. A 3X will take about 10-12 blows to set a #5. A 2X doesn't have the juice to drive a #5 rivet.

 

[Arrow67]

Hi I was hoping someone might be able to explain the difference between 2X, 3X, 4X etc. rivet guns.

I have been looking at various sites and manufacturers and like the look of atlas copco. A bit on the expensive side I know but I have previously used some of their other tools in my past employment and know I'm paying for quality.

I've been looking at their different 3x rivet guns and have found two that are massively different and is making me question what the references "2X" "3X" "4X" and so on actually mean?

One 3x rivet gun I'm looking at has 2160 blows per minute at 6j on energy per blow while another 1920 bpm at 3j per blow. My initial thought was that blows per minute and energy per blow were what led to the designation of "3X" or maybe it was total energy transfer per minute (bpm x energy per blow) but both of those don't seem to be the case, and I know atlascopco have been around for years so it's not even like they're a no-name Chinese brand just saying "oh yeah these are definitely for aviation" and just slap whatever labels on them they feel like.

Google says it's something to do with the power and size of rivet it can drive, but surely a 3/16th rivet (or whatever size) would need the same amount of energy to drive?

So could someone please explain this to me as I feel like I'm being a total idiot...

The guns in question:

RRN 18P | Atlas Copco US

RRN 18P

www.atlascopco.com

RRH06P | Atlas Copco US

RRH06P

www.atlascopco.com

Thanks!

The numbers 2X 3X 4X refer to how strong the gun hits and what size rivets it is meant to drive. A higher number means a longer stroke and more force per hit.


2X is for small rivets in thin material. It hits fast but light.
3X is the common all round size. It can handle most aircraft rivets up to about 5/32.
4X is slower but much stronger. It is used for larger rivets like 3/16 or for thicker material.


So the number is not about blows per minute. It is about how powerful each hit is and what rivet size it is intended for. This is why two 3X guns can feel different depending on build and tuning.