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Sub' the coarse pitch small diameter screws for upward to 5/16 diameter, matching nylon insert lock nuts both fine pitch and of stainless steel. Such hardware may be found in small quantities at a 'cheap' price at HD, Lowes Ace etc. A large diameter hex head bolt provides it's own knob and the fine pitch adds 'more turns with less movement'. Stainless steel will permit long storage without rust.
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