63-65 Convert Manual Top Hold Down Latch Spring Steel Help

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Dana67Dart

The parts you don't add don't cause you no trouble
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Hi all,

I have been working with @azaustin to make an OEM style factory manual top hold down latch.

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In our haste we neglected to measure the holes in the spring steel the latch originally was riveted to.

(The top 2 holes)

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The latch I'm making will be a bolt on (most of us do not have rivet presses and pop rivets look like... pop rivets) and I would rather size the screw to go through the OEM holes rather than require the user to re-drill the holes larger.

When I design a part I try to make it look and function OEM as much as possible. I also do not want to modify an OEM part if at all possible to make a replacement part fit. By making this screw on it can be easily changed in the future if need be and for those worried about the screws coming loose, a drop of removable Locktite will do the trick.



The screws on the left are 5-40 and are 0.125 OD shaft
The screws on the right are 4-40 and are 0.112 OD shaft
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WHAT I NEED....

I need someone who has the spring metal that they know has not been re-drilled to use pin gauges or numbered drill bits to find the size or at least the Go/No Go sizes.



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Thank you in advance.

Dana



Life Hack... Harbor Freight as well as other online sources have numbered drill bit sets

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Typically in the sub $40.00 range, sometimes in the $10.00 range for the smaller kits on sale. Do not use them for drilling so they stay pristine and then use them as a super inexpensive pin gauge set. After you find the drill shank that closely matches the hole, measure the OD of the drill shank with a caliper and there you go. The benefit of this over a true pin gauge set is typically the holes will be numbered drill bit sizes anyway. Disclaimer... this is not accurate enough for engine building or aerospace. :rolleyes:
 
Dana - after reading your post I decided to go back and look through the photos I took while we were taking our first measurements. Sure enough I found the pictures I was looking for. They are attached. One photo shows the numbered drill bit I used to go/no-go (#131, .120) and a picture of it in the hole on the nylon part you sent. A #30, (.128) was too big and wouldn’t fit. I’m pretty sure I did the same thing with the bracket, but if someone can verify it, that would be great. Also, I was able to get a self-locking nut for the 6-32 screws I used, and they are also available in some smaller sizes I think. Thanks for all your work.

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