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Old 16th Mar 2021, 12:06 am   #17
Nanozeugma
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Join Date: Nov 2017
Location: London, UK. Bury, Lancashire quite regularly :)
Posts: 609
Default Re: Enlarging an existing hole in a steel chassis.

Thanks to everyone for their input and thoughts.

In the first instance, it's my fault that I made the assumption that all drop through B9A sockets are created equal, diameter size anyway.

The originals are ceramic, and I wanted to replace with ceramic but ideally with gold plated pins for better resistance to oxidation.

Therefore, I ordered, and have to hand, sufficient sockets of the type I wanted to fit - except that the ceramic bodies are too large for the chassis holes.

I can quite see the logic of tearing up that idea and obtaining sockets that will fit without enlarging the chassis holes, but they would not be what I wanted.

So, having obtained the sockets, I am, so to speak, committed to using them. All that is required being to enlarge the chassis holes by about 3mm, the bolt mounting centres are, fortunately identical.

Of the possibilities suggested, I rather like the idea of a suitable cone drill.
The chassis is mild steel, approx 1.3mm thick and there is adequate room to use a cone drill.

The problem I have is selecting a suitable specimen.
Reading users experiences of cheap ones tends to suggest that they blunt at anything mildly resistant. Prices range widely.

It would be ideal if someone could point me to **one that experience has proven is successful** pitted against thin(ish) mild steel.
I obviously don't want to spend an arm and a leg on something that I may, quite possibly, never have to use again.

I am, however, grateful to all those who have taken the time to volunteer ideas and experiences (in case you thought otherwise!)
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