Fisher 400 transformer bolts

[ncwalz]

Just wondering if anyone knows offhand the proper name and size of the bolt that secures the power transformer to the chassis. I’m missing one and would like to replace it. I think it is the same as the bolts that secure all the transformers in the 400, 500b,c and 800b,c line.


I’m just not sure the proper nomenclature (panhead maybe?) and the best place to order. Thanks.

 

[egellings]

A round headed bolt is often called a machine bolt or machine screw. If you are putting a long bolt through the transformer's lamination stack, be sure to wrap a bit of insulation around the bolt. That way, if the bolt touches & shorts laminations together, it will not be a cause of possible eddy currents.

 

[fred soop]

https://www.albanycountyfasteners.com

Whatever screw, nut, bolt, etc. that you may need.

 

[The Fuxtor]

Maybe take one out and go to Home Depot? They got the measurement board you can screw the bolt into to identify the size? Btw I have a bunch of insulators I 3d printed. Not sure if they are needed for Fisher trannys, but my buddy needed a bunch for his Dynaco mono blocs.

 

[The Fuxtor]

The screw is a #8 just to test for sizing....

 

[ncwalz]

Thanks guys

 

[larryderouin]

If you have a local Mom & Pop Hardware Store try them before the Big Box Stores. Pan Head, Straight slot 5/8" or 3/4" long. 1/4" diam or 5/16" diam. (Mine are in storage right now.).

 

[ncwalz]

Thanks Larry!

 

[fred soop]

A round headed bolt is often called a machine bolt or machine screw. If you are putting a long bolt through the transformer's lamination stack, be sure to wrap a bit of insulation around the bolt. That way, if the bolt touches & shorts laminations together, it will not be a cause of possible eddy currents.

Good point. But, if the mounting bolts are isolated from the transformer, then a ground wire should be added by loosening one of the covers and inserting the end of a wire to ground. Otherwise, the copper shield is not grounded.