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Who makes these exhaust clamp bolts? (Socata TB20 exhaust clamps)

Peter – Reality check:

What do you know about Swiss planes ?

Ever owned a German or Italian built plane ?

The reality is that Pilatus, Diamond and Tecnam, all use non-standard parts. I can assure you that the Pilatus beats Socata in the “over engineering” category and the cost of parts will make you dizzy.

ps: I have a $50K stash of Pilatus, Diamond, Robin & Socata parts …

FAA A&P/IA
LFPN

Just an update:

ARP (the best quality option found) do not ship outside the USA, their UK/European “dealers” are useless, but with Silvaire’s kind help I have a bag of the M6 ones in front of me.

The locking nuts came from elsewhere.

All top grade stainless steel, high temperature, way better than the original Socata stuff, and about 1/50 of the price.

Administrator
Shoreham EGKA, United Kingdom

The bolt – sheer engineering perfection right down to the radius under the head – was available as 6-point or 12-point. I could not see any point (haha) in the 12-point one.

Administrator
Shoreham EGKA, United Kingdom

The more points you have one can manipulate a spanner (degrees of motion) better in a confined space.
Is that a valid reason ?

Regret no current medical
Was Sandtoft EGCF, North England, United Kingdom

I’d be interested in obtaining some of these bolts mentioned earlier in the thread.

I am also looking for the TB20 exhaust clamp itself P.N. TB1056008001 (No.130 in diagram) which is a mind blowing €123.62 per clamp plus VAT and shipping. I have a couple of these that are leaking.

The clamps have a very thin inner metal band that acts as a seal, which wears away.

EGLK, United Kingdom

I obtained some bolts from the sources mentioned, at the time. The washers (item 150) would need to be machined up, but it is debatable whether they are necessary.

This in my TB20 writeup should be of interest.

Most maintenance people bugger up these clamps, due to the reasons mentioned in the above link.

You can extend their useful life by packing them with the Halfords exhaust gunge

but you have to wait several days before starting up the engine otherwise the leaking gas blows the stuff out.

The clamps can also be repaired – see the link.

Administrator
Shoreham EGKA, United Kingdom

Traditionally exhaust manifold nuts are brass to avoid snapping off the studs, which is what happens when steel nuts are used.

Darley Moor, Gamston (UK)

Can anyone work out the specification for this bolt?

I believe it is the one sold by Socata for use with their exhaust clamps, as per this thread, so it should be (and indeed looks like) stainless steel, but it may not be anything special.

Administrator
Shoreham EGKA, United Kingdom
I have never seen that stamp, maybe a company stamp. When it is stainless it should be marked with A2-70 or A4-80 , that shows the tensile strength. Or in case of high temp types the material type is stamped like 4828 or 4848 or so. I´d simply take A 4 screws and see what they do in long term, can not be worse than the corroding Socata items. For securing the nuts I have certainly used MoS2 paste on the threads, nothing else on high temps places. Two of them get locked each other and that does it, period. The clamp would no way hold the max. strength of the A 4 bolts so this is not critical in plain real life. Vic

vic
EDME

here is a uk supply for high temp k-nuts (stainless steel silver plated) that are used on turbos and also on exhaust flange to cyl head on racing engines
Simmonds is a large French company for fastners that supplies aviation indusdries

example as used on turbo

Last Edited by Peter_Paul at 28 May 21:14
fly2000
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