Ideas needed for Striker Plate

[Captain Obvious]

One last thought on this project. Should you decide to stick with the 7mm bolt idea... I would hate to find an 11mm headed bolt where a 10mm head should exist.

You would only need to grind off about .020 per flat to get the head size down to 10mm where it belongs. Surely there's enough meat on the head to do that. You'll grind through the plating, but you'll have the correct size head. If you started with un-plated stainless, you wouldn't even know the difference from the outside.

[Patcon]

On 3/13/2018 at 9:56 PM, Captain Obvious said:

One last thought on this project. Should you decide to stick with the 7mm bolt idea... I would hate to find an 11mm headed bolt where a 10mm head should exist.

You would only need to grind off about .020 per flat to get the head size down to 10mm where it belongs. Surely there's enough meat on the head to do that. You'll grind through the plating, but you'll have the correct size head. If you started with un-plated stainless, you wouldn't even know the difference from the outside.

Or he could mail me the modified one and I could plate it for him...

[SteveJ]

Well, I figured I would try @Diseazd's suggestion and reached out to a machine shop. So far, they haven't gotten back with me.

Plan B (per @Zup) - I ordered a heli-coil kit and will test on some M6 nuts to see if I like my competence. (I have also been watching Youtube videos to get details I might otherwise miss.)

Plan C - I will practice drilling out and re-tapping M6 nuts with an M7 tap.

[SteveJ]

In doing further research, I'm glad I have decided to play with different ideas before implementing one. I was wondering about the minimum depth of material for using a helicoil, as @grannyknot has warned. I found this link: http://www.noblefix.com/helicoil/HeliCoil-Tapping-Chart.html. It expresses a depth of "H" that can be looked up in the chart on the page.  It appears as though the minimum depth needed is 7mm. If that's the case, there could be an issue with using a helicoil since I know the material thickness is less than 7mm.

Just in case, I did just order some 6mm deep M6 inserts. 

I'm going to end up knowing more about helicoils than I ever wanted to.

[SteveJ]

And the winner is...

Heli-coil!

I practiced with a piece of 1/4" steel plate. It held well. 

I used one of the good captive nuts and striker plate to center the bad one in the hole. I drilled out the hole with a 1/4" bit, tapped it carefully, and ran the M6 Heli-coil in.

I ended up having to change out the door lock and striker plate, but I did finally get a good latch.

Thank you, all, for posting solutions and opinions. It helped guide my research and come up with a workable solution.

[Captain Obvious]

Excellent. I love it when a plan comes together.

I assume your door closing issues that started this entire debacle have been remedied?

[SteveJ]

1 minute ago, Captain Obvious said:

Excellent. I love it when a plan comes together.

I assume your door closing issues that started this entire debacle have been remedied?

I hope so. The door was latching properly when I stopped for the evening. I'm keeping my fingers crossed that it stays that way.  

[Captain Obvious]

Good!