I can't help, but I'm after a bag too!!!

 

https://www.ebay.co.uk/itm/50-x-VW-AUDI ... 1784195797

 

Find a scrappy where they stack cars and take wheels off.
Makes it really easy to amass a large stock.
Useful for many cars.

 

https://www.ebay.co.uk/itm/50-x-VW-AUDI-ENGINE-COVER-UNDERTRAY-SPLASHGUARD-WHEEL-ARCH-TORX-SCREW/321784195797

Damn, and I just spent $30 at the dealership for 20 of these

 

Thanks TT-Dru but I'm 95% certain those are the mild steel ones I already have a bag of.

The backup option is to buy a new lot, rinse them in brake cleaner, spray them in zinc primer and then coat in Bilt Hamber or ACF50 once they're screwed in, but they'll still go rusty so it seems like a pointless mission.

The screws are apparently No. 10 size by either 5/8" (16ish mm) or 3/4" (20ish mm).

With the random screw I have lying next to my desk, my ChineseBay calipers give me measurements of 0.18"/4.7mm thread, 0.77"/20mm length, 0.58"/14.7mm head diameter.

Apart from the wider head, this is a very commonly-available stainless screw size on fleabay, e.g. 100 of these are £6.64:

Or 100 of these allen-headed screws would be £7.99:

Or these Torx head screws - £6.40 for 100:

All three have slightly smaller heads, so I would probably also want a bag of 100 of these M5 x 15mm x 1mm washers at £3.70:

I guess the question would then be, do I go for screws which look more like the existing Torx head screws, or allen-head bolts which look a bit more "proper" than having random screws dotted around?

I'm definitely not keen on the idea of paying £20+ for a small handful of the "proper" screws... :x

/Al

 

What would be the problem with the mild steel version linked by TT-Dru above - for that price when they start to rust a year or 2 down the line, just stick a new one in

 

The problem is they seize into the captive metal spring washer things they screw into, so they're impossible to remove unless you drill them out, snap them, or snap the mountings

 

Try these:

https://www.stainlessmiddleton.co.uk/

https://www.accu.co.uk/797-shop

 

Try these:

https://www.stainlessmiddleton.co.uk/

https://www.accu.co.uk/797-shop

Cheers bud, I'll have a lookski

 

The problem is they seize into the captive metal spring washer things they screw into, so they're impossible to remove unless you drill them out, snap them, or snap the mountings

Cheers fella, yeh i can see why that wouldnt be ideal then

 

You could fit stainless spire nuts on the chassis side, to match the screws, more flexibility on screw choice, if you buy screw and nut together, that could be a solution. Mac.

 

I would go for allen head bolts. Maybe try these in a zinc finish: https://www.accu.co.uk/en/159-cap-head-screws

 

Thread resurrection

I don't own a TT but have been searching for months for some stainless replacements for the screws which attach the mudflaps to my B6 A4 Avant. My searches kept throwing up this thread asking the same question. Well I finally found it, they're on eBay but no mention of torx etc; they're sold as numberplate/bumper screws and I've just received them from Hong Kong from this seller: https://www.ebay.co.uk/itm/8pcs-5-x...cense-Plate/401755569899?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2648

The seller also has different size threads/lengths so I think you'll be able to get the ones for the arch liners/undertrays too although I've yet to try that but these are certainly a good replacement for the mudflap ones although the flange isn't quite as wide. I was a bit skeptical about the black finish at first, I don't know if it's paint or some kind of plating (they're all bag marked anyway) so I soaked one in a solution of saltwater for a week and then left it to air dry - no rust. Anyway here's some pics, some with the 17yr old original for comparison:

 

I was a bit skeptical about the black finish at first, I don't know if it's paint or some kind of plating

I got a handful from a TT breaker locally and quite a few of the stainless ones were painted black, so it doesn't seem to be unusual.

Interesting link, thanks for posting them. I've been trying to get around to doing something on mine with these - the handful I got were destined to be stripped and plated, but I'm not sure it's worth the fiddle.

 

I think the black finish is chemical. Some sort of oxidation. On stainless, it's primarily for appearance or non reflectivity.
Mac.

 

(Thread starter here) This is annoying - having forgotten I’d posted this thread, and in need of replacement screws because Shed’s rear valance screws appear to have gone missing, I Googled stainless torx trim screws for the Audi TT and ended up back here…

So, thank you Oldscholar for the recommendation - I’ve ordered £20-worth of those trim screws from the Chinesebay seller you linked.

If they ever arrive and I remember this thread, I will pop back in and update as to how good they are

Al