...Not the operator...

[Bootlegger]

    Now that I have your attention, here is the question, what size are the bolts in a Brodak 40 ?  Are they 4x40 or what   I know that the "lurkers" on the Stunt Hangers on will know and "Inquiring minds want to know"...

[Bob Zambelli]

All bolts are metric - I do not know the size offhand.

Only the crankshaft and glow plug thread are U.S.

Bob Z.

[Chuck Feldman]

Take some of your bolts to ACE Hardware. they have metric bolts.

Chuck

[Bootlegger]

   Guy's I thank you for the info. I went to the shop and found some OS 40 bolts and they are the same as the muffler bolts. The size is M3x12 MM long so if you need them go to your local bolt supplier and ask for this size...
 Again thanks for the suggestions...

[Garf]

Brodak, LA, & FP use the same thread, but different lengths. I bought 100 of the M3 X 12MM from McMaster Carr. I have a lot left over.

[don Burke]

An M3 x 12 screw is 3mm diameter x 12 mm long.  What's the pitch?  The pitch also needs to be noted to make a good match.  Just like SAE threads there are coarse, fine, and extra fine and so on in metric threads, stated in mm, 0.5. 0.6, 0.75 etc.    In some cases the difference is so small that an incorrect pitch bolt can be screwed into another pitch hole, with resulting thread damage.  So be sure of the pitch as well as the diameter and length.  The proper callout would have been M3 - x.x X 12.  Matching the B-40 threads to the OS ones was a lucky circumstance.  Could have been disaster.

Unfortunately the bags of stuff in the hobby shops normally do not have the pitch noted, as stated be careful.

[Bootlegger]

Don, All the info that I have is what I posted, I thought that there would be a "pitch" on it also, but I didn't see one on the box.
  If it is there I sure did miss it and I don't have any pitch gauges for SAE or metric screws...

[john e. holliday]

That is why when I go to my lodal ACE Hardware I take the engine and/or muffler to try the bolts first before I buy them.  Have fun,  DOC Holliday