Set screw materials

[Quinten]

I need a few set screws to mate my RS2000 (alu?) bellhousing to my 1.8 silvertop Zetec (iron?) and would like to confirm I can use A2 stainless steel set screws without any issues?  No cold welding (I think that was what it was called) ?

The same question applies to the engine mounts (steel?).

[AdamR]

I would go for cromo bolts in these areas... 8.8 grade minimum.

 

[Mark (smokey mow)]

In those situations stainless fasteners may cause you problems long term unless you can isolate them.

steel, zinc, iron and aluminium all have similar anodic electrotytic potential and therefore will work well together whereas stainless is cathodic and at the opposite end of the galvanic series. Therefore long term stainless could accelerate the corrosion process for the metals it is in contact with.

[Quinten]

56 minutes ago, AdamR said:

I would go for cromo bolts in these areas... 8.8 grade minimum.

I can only seem to find BZP, A2 or A4.  I don't suppose you have a link?

 

12 minutes ago, Mark Wendon (smokey mow) - WSCC Club Secretary said:

In those situations stainless fasteners may cause you problems long term unless you can isolate them.

steel, zinc, iron and aluminium all have similar anodic electrotytic potential and therefore will work well together whereas stainless is cathodic and at the opposite end of the galvanic series. Therefore long term stainless could accelerate the corrosion process for the metals it is in contact with.

And in laymans terms...?

[AdamR]

BZP (Bright Zinc Plated) is normally a cromo bolt, usually will have the grade stamped into the head - 8.8, 10.9 or 12.9 (bigger numbers = strongerer!). What size are you after?

 

[Quinten]

2 minutes ago, AdamR said:

BZP (Bright Zinc Plated) is a cromo bolt, usually will have the grade stamped into the head - 8.8, 10.9 or 12.9 (bigger numbers = strongerer!). What size are you after?

 

Ah, thats ok then.  i'm after M10 x 40 and a few smaller M10.

[AdamR]

If you only need a couple, then eBay is a good shout. There are cheaper places for the bolts alone, but delivery is usually £3-4 minimum.

http://www.ebay.co.uk/itm/SETSCREWS-HEX-HEAD-BZP-FULLY-THREADED-SCREWS-BOLTS-M4-M5-M6-M8-M10-M12-M16-M20-/222335497492?var=&hash=item33c43a7514:m:mazmw-6k7Kr7e35w81Dctgg

 

 

[Andy (Sycho)]

There's loads on ebay

http://m.ebay.co.uk/itm/High-Tensile-Set-Screw-8-8-Grade-Zinc-Plated-Bagged-Forgefix-/282120605895?var=&hash=item41afb2d0c7%3Am%3AmSnSGOMzq6z4CtXoiANfrIg&_trkparms=pageci%3A10505b47-c5db-11e6-816d-74dbd1a068ea%7Cparentrq%3A16c211831590a7850437a5b8ffd0bfd6%7Ciid%3A14

[Quinten]

Oh yes, now I know that BZP is ok, I know where to find them