Wait until Jason sees this.!

He will consider it nothing short of blasphemy that you should even consider hex screws let alone mention them over studs and nuts. And also the correct profile of nuts.!

Nick

Actually a lot of steam chests/covers on locos are held on with csk head slotted screws. Often there is not enough clearance between the valve chest cover and the running board to get nuts in. Sometimes the steam chest is also secured to the block by a couple of csk screws through the steam chest only and between the normal fixings. That way the chest is still secured when the cover is removed for valve timing etc. A chassis I'm working on at the moment has that feature.

As suggested though, studs and nuts are the best way really. I've had a few locos where someone has been a bit over enthusiastic tightening bolts and stripped the threads in the block

John

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Thus making proper studs.

I know little of Steam practice [either full-size, or miniature] but it seems that normal "good engineering" principles would apply.

MichaelG.

Julian beat me to it, if your prototype is old enough, square head bolts, and studs with square nuts. someone else can start the argument as to which way up the nut should be.(don't go there),

Ian S C

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JA … For reference here is "there"

Enjoy

MichaelG.