Stuart Model Detail Clarification

[atomarcParticipant @atomarc]

I’ve returned to the shop to continue a triple expansion build I started in 1981, and being old and foggy in the head now, would like come clarification on some part detail notes. This part calls for a 7BA CLR hole on one end, and a 7BA DEAD hole on the other end. My interpretation would be that a CLR denotes a ‘clearance hole while a DEAD indicates an exact diameter for a 7BA fastener.

 

Is this correct?

Thank you,

Stuart Miller

Eureka, California  USA

 

[JasonBModerator @jasonb]

They tend to use CL as clearance size which can be whatever you feel happy using

In the case of 7BA Dead on a part like the valve rod clevis then that should be a close fit to the plan shank of a 7BA “Fitted” bolt as you do not want any loss of valve movement or fretting that a looser clearance hole would give. Something like that you could ream 3/32″ and make your 7BA bolt with a 3/32″ shank, the thread will cut OK onto the slightly smaller than nominal 7BA major diameter.

If you don’t have a 3/32″ reamer then drill the hole 3/32″ and then turn the bolt shank to fit whatever size the hole actually comes out at.

[atomarcParticipant @atomarc]

Jason,

Thank you for that very succinct and quick reply, it’s just the information I was looking for.

 

Stuart Miller

[Author]

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