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Stuart Turner Print Question

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  • Stuart Turner Print Question

    I dug out a Stuart Turner triple expansion steam engine kit I've had for a million years and have started to finish where I left off.

    These kits use British Association fasteners (BA) and I'm not real clear on some of the notations on the prints. There are notations for drilled & tapped, clearanced and the one in question, 'DEAD'? I would assume a hole that was marked as 'DEAD' would be the exact diameter of the unthreaded portion of the fastener. This would result in a light push fit. Does that sound correct?

    Any thoughts?


  • #2
    Are these the ones in the valve gear components marked '7BA Dead'? They probably mean drill 3/32" which is the nominal diameter for 7BA. I've never been that struck by ST's practice for valve gears, which uses mild steel bolts in drilled or reamed holes in mild steel. Usually I change them so that the bolt is shouldered, there is a bronze bush in the central component, and one side of the jaw has a thread to take the threaded end of the shouldered bolt with a lock nut on the outside.

    'It may not always be the best policy to do what is best technically, but those responsible for policy can never form a right judgement without knowledge of what is right technically' - 'Dutch' Kindelberger


    • #3

      Yes...those are the ones. I have been drilling the holes marked 'dead' with a #39 drill. That size allows the shank of the little stud to lightly push through by hand.