Milspec Grommet Installation

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Kyle Boatright

Well Known Member

• Apr 5, 2020

• #1

I went to install the grommets on my Milspec fasteners today. The holes in the cowl are the specified 15/32nds and I cannot persuade the grommets to snap into the cowl. I don't really want to go brute force on this, 'cause they are gonna have to come back off for paint.

Is the solution as simple as slightly opening up the hole with a round file?

 

rocketman1988

Well Known Member

• Apr 5, 2020

• #2

Suze

You might check your 15/32 bit with a micrometer. I found mine to be undersized...

 

goatflieg

Well Known Member

• Apr 5, 2020

• #3

Did mine today too; they were just barely undersized. Some light reaming with a deburring hook and smoothing with sandpaper was all that was needed.

 

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Kyle Boatright

Well Known Member

• Apr 5, 2020

• #4

rocketman1988 said:

You might check your 15/32 bit with a micrometer. I found mine to be undersized...

Click to expand...

If I could only find the micrometer at this point...

I swear it's around here somewhere.

 

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Kyle Boatright

Well Known Member

• Apr 5, 2020

• #5

Follow-up:

My Irwin unibit was about 0.020 undersized on the 15/32 step. Strangely, my Harbor Freight 15/32 centerpunch (one from a set of about 30 sized punches) was dead on...

 

flion

Well Known Member

• Apr 6, 2020

• #6

Better relieve them a bit more for paint clearance. They can be a bit loose, the retainer will keep them in. And there's plenty of bearing surface on the outside.