Author Topic: Aerospace lock nuts - work question (Read 6170 times)

tris · « **on:** February 25, 2016, 04:56:32 AM »

Morning all

I'm trying to track some 12 point flanged lock nuts down and our engineering department want to know the ISO/ASME/BS/DIN standard that applies.

I'm struggling though as I suspect that they are propriety items and aren't made to an international standard.

So what to you aerospace types call these please

Cheers

Tris

clubman · « **Reply #1 on:** February 25, 2016, 05:41:51 AM »

McMaster-Carr has them listed as "High-Torque 12-Point Flange Nuts" available in crome-moly or A286 stainless. They don't however list engineering specs for these nuts, as they do some others. Give them a call, 404 346 7000, and they can probably come up with a manufac. spec. sheet. Good luck.

Chuck in Indiana · « **Reply #2 on:** February 25, 2016, 05:52:46 AM »

I've seen them on helicopters in high temp areas, but I don't know what they're called, either.

tris · « **Reply #3 on:** February 25, 2016, 05:57:27 AM »

CM
Cheers I'll take a look but if they're not showing a spec could be because there isn't one!!
PS
I'm based in the UK so don't use McMaster - could you shoot a linky over please?

CinI
That'll be them.

We use the to hold the top and bottom halves of an industrial gas turbine together - so hot too!

Somebody will know what they called

Dean Rose · « **Reply #4 on:** February 25, 2016, 06:02:17 AM »

Quote from: tris on February 25, 2016, 05:57:27 AM

CM
Cheers I'll take a look but if they're not showing a spec could be because there isn't one!!
PS
I'm based in the UK so don't use McMaster - could you shoot a linky over please?

CinI
That'll be them.

We use the to hold the top and bottom halves of an industrial gas turbine together - so hot too!

Somebody will know what they called

http://www.mcmaster.com/#

tris · « **Reply #5 on:** February 25, 2016, 06:42:41 AM »

I like McMaster Carr - we don't have anything close to that over here :cry

John A · « **Reply #6 on:** February 25, 2016, 07:47:59 AM »

We always called them jet nuts or heat nuts. Try Rolls Royce, they should have published specs. Pratt&Whitney too. They may not be real forthcoming on the specs, being proprietary but maybe an aftermarket aviation supply will say if an item meets specs, they should be able to furnish those.

Groover · « **Reply #7 on:** February 25, 2016, 08:08:29 AM »

Looks like clubman nailed it:

Here is a PDF with info and website info:

http://www.afsrsimmonds.net/pdf/M3k6913_Flier_DHE_Final.pdf

They're in France though I think.

John A · « **Reply #8 on:** February 25, 2016, 08:24:56 AM »

Groover nailed it!

dsrdave · « **Reply #9 on:** February 25, 2016, 08:35:47 AM »

We always called them jet nuts. Used them a lot on the race car. Many racing suppliers (pegasus an such) will stock them at a fair price and may have specs avail.

tris · « **Reply #10 on:** February 25, 2016, 08:44:02 AM »

Quote from: John A on February 25, 2016, 08:24:56 AM

Groover nailed it!

YEP - Groover nailed it.

I knew of Simmonds but hadn't found that spec and specifically ISO 8788-2000 Annex E

All personnel may now stand down and thanks for all your input

Tris

Groover · « **Reply #11 on:** February 25, 2016, 08:54:34 AM »

I can't take any of this credit! All I did was Google what Clubman defined as the name of the nut, so Clubman gets the points!

acogoff · « **Reply #12 on:** February 25, 2016, 09:31:49 AM »

Looks like the NAS 1804 series similar to what the old Hillers had holding a lot of their transmission component together
I think the 12 point is referred to as "double hexagon". Handy little nuts they are space wise. Solve a lot of tight engineering problem areas.

lucky phil · « **Reply #13 on:** February 25, 2016, 02:34:00 PM »

Yes looks like an NAS flanged multihex nut and probably falls under a MIL spec somewhere.
Seen literally millions in my career on everything from wheel hubs to turbine and compressor cases.
Finishes differ from a "black" finish to a silvery white depending mainly on the environment it has to deal with.
Ciao

tris · « **Reply #14 on:** February 25, 2016, 04:22:42 PM »

Cheers all
I'm looking for the metric version Is there any metric NAS or are they all inch sizes?

RinkRat II · « **Reply #15 on:** February 25, 2016, 05:33:31 PM »

Hey Tris .
ARP here in America has what your looking for and they may have distribution in Europe
http://arp-bolts.com/

Paul B

HardAspie · « **Reply #16 on:** February 25, 2016, 05:43:44 PM »

I have seen advertised 12 point wrenches to get a very good grab on these things. I think that for their size they can accept large set torque.

Chuck in Indiana · « **Reply #17 on:** February 25, 2016, 08:14:39 PM »

Quote from: tris on February 25, 2016, 04:22:42 PM

Cheers all
I'm looking for the metric version Is there any metric NAS or are they all inch sizes?

Yep, Eurocopter uses them..metric sizes.

mrrick · « **Reply #18 on:** February 25, 2016, 09:13:18 PM »

Metric. In Belgium.
http://www.anemo.eu/node/1075

mtiberio · « **Reply #19 on:** February 26, 2016, 06:13:30 AM »

carrillo rods came with "SPS-Carr" nuts which looked like that

mtiberio · « **Reply #20 on:** February 26, 2016, 06:19:36 AM »

http://www.spstech.com/home/

John A · « **Reply #21 on:** February 26, 2016, 07:45:26 AM »

Quote from: Chuck in Indiana on February 25, 2016, 08:14:39 PM

Yep, Eurocopter uses them..metric sizes.

On MBB (Eurocopter) BO 105 helicopters the engine to main transmission driveshaft bolts were "on condition " but changed to one time use. They fit the Guzzi crown wheel perfectly. Nice bolts, ground threads, serial numbered and all that. The rest of the helicopter is metric, with the exception of the engine, Allison C20, now Rolls Royce. A lot of very nice metric hardware, wish I would have pocketed more"work order residue"

Chuck in Indiana · « **Reply #22 on:** February 26, 2016, 10:52:51 AM »

Quote from: John A on February 26, 2016, 07:45:26 AM

On MBB (Eurocopter) BO 105 helicopters the engine to main transmission driveshaft bolts were "on condition " but changed to one time use. They fit the Guzzi crown wheel perfectly. Nice bolts, ground threads, serial numbered and all that. The rest of the helicopter is metric, with the exception of the engine, Allison C20, now Rolls Royce. A lot of very nice metric hardware, wish I would have pocketed more"work order residue"

Nice hardware, all right. I'll bet they cost enough to make the suspenders wearing Guzzi Guy drop his pipe.

John A · « **Reply #23 on:** February 26, 2016, 02:19:31 PM »

And swallow his snoose at the same time!

Kiwi Dave · « **Reply #24 on:** February 26, 2016, 03:14:33 PM »

Didn't Triumph use these type of nuts to hold the barrels on to the crankcase? I've got a few flowing around here somewhere.

RayB · « **Reply #25 on:** February 26, 2016, 04:02:14 PM »

.....and the later BSA A65s but without the sleeve on top

Chuck in Indiana · « **Reply #26 on:** February 26, 2016, 06:18:11 PM »

Probably not quite this quality..

Quote

Nice bolts, ground threads, serial numbered and all that.

or price.

John A · « **Reply #27 on:** February 26, 2016, 07:38:58 PM »

I think those driveshaft bolts were only about 300 bones apiece.

jabberwocky · « **Reply #28 on:** February 26, 2016, 08:56:51 PM »

Some later airheads used these on the final drive to swing arm studs, I think 10mm threads.

HardAspie · « **Reply #29 on:** February 26, 2016, 08:58:29 PM »

Quote from: John A on February 26, 2016, 07:38:58 PM

I think those driveshaft bolts were only about 300 bones apiece.

Aviation certification and product liability adds a bit to the price.

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Author Topic: Aerospace lock nuts - work question (Read 6170 times)

HardAspie

HardAspie