Cat. Bolts

[daka]

I'm going to take my cat off the 87 Targa to check it, I want to replace the bolts with S/S. What size bolts to have ready...will probably only be able to get SAE locally...ok to use S/S washers?
It looks like original at 145,000 miles and pretty rusted fasteners!

[nhromyak]

I put S/S on mine, but I don't recall the size off hand. I would have to look.

I found metric ones at my local Orchard Store Hardware (OSH). I got some that are .5 mm longer than stock, just so it would be easier to put them on.

I also used a touch of anti-sieze so they won't be such a PITA next time.

As I recall, they are all the same size and length. Take one out and take it to your local hardware store, and see what you can get.

I think if you get SAE you will have problems getting them to fit. It's pretty tight when you begin to line it all up.

Oh well, I am sure someone here has a better more definitive size answer... sorry.

[Wil Ferch]

I posted this kind of stuff many times before.

Summary:

5/16" x 18 pitch, 1.5" long under head, partially threaded 316 Stainless bolts.
Matching nuts are Si /Br ( Silicon Bronze). These have 1/2" heads and work with 12 or13 mm wrenches. Very close dimensionally to stock 8mm x 40 mm long regular steel bolts. Same 12 or 13 mm wrench size for bolt heads....same tools ! Non galling combo and no need for messy anti-seize goop.

Wil

[jbrinkley]

M8 (pretty sure)
edit, home depot and lowes have em

[masraum]

Stainless bolts with stainless nuts will be a problem, but I think Bill or Wil uses some sort of silicon bronze nut or something like that to keep from having the nut gall to the bolt.

[Wil Ferch]

Steve:
See my post above which indeed answers this point....thanks for remembering....

Wil

[daka]

Thanks guys,
ALWAYS a definitive answer...great info

[sushinav]

Hey Will,
What is "galling," what causes it, and where do you get silicone bronze nuts? Is that something a competent hardware store should have?

[JP911]

I used stainless steel to attach a Dansk 2-in 1-out about a year ago and when I removed it recently to try out a 2-out Dansk the nuts were galled (basically welded to the bolts). I ended up snapping off 2 of them and had to dremel the other 2. Lesson learned.

[Wil Ferch]

McMaster-Carr has the Si/Br nuts which were discussed here previously , too..including parts numbers...

Wil

[3.2 CAB]

Generally the Si/Br nuts and bolts can be found at a boat, or marine supply house. If you have a speciality fastener store handy, you could get all the items there. Where you live (near salt water) you shouldn't have any problem locating these fasteners.

[Teutonics]

I just ordered these from McM/C, and they only come in packs of 25/50.... I don't need that many. If anyone needs some, I have extras. Send me a PM or email if you want some.

[Jim Sims]

If you insist on stainless screws with stainless nuts use lots of anti-seize lubricant or milk of magnesia on the threads! Then hope for the best. Jim

[daka]

OK OK, We have a lot of marine supply places here in Fort Lauderdale, I will buy S/S bolts and Si/Br nuts and washers (if there is such thingies)
Thanks for all the good advice
Daniel....now where is that torch to remove them.....

[JeremyD]

I had to dremel all of mine off my 1987 - hope heat works for you

[Wil Ferch]

True...Mc/M sells these Si/Br nuts in smallest quantities of 25 or 50...but the out-of-pocket cost for the smallest pack was like $10....

Extras are nice to have around and it isn't like you're buying titanium, etc....

The whole idea is to have repeatable / removable hardware without the anti-seize mess...

Wil