Any experience with tapping 000-120 threads in copper alloy?

[SShep71]

I have a unique project that I came across, I need to make a special pin for an Amphenol connector or adapt the existing pin to work for this application. In order to make the existing pin work I would need to tap the existing connector with a 000-120 NS tap. The material is gold plated copper alloy (from what little information is available). I have one pin to work with and one spare pin, then I am up a creek. This is not an avoidable project as this NEEDS to be done, I am still looking at other ways to solve this but for now this is the best idea I can come up with. Does anyone have any experience working with such a small diameter tap size that they can provide any suggestions, help, or real world experience?

 

[AJ H]

Perhaps see if you can get someone to edm the thread for you

 

[rklopp]

Does anyone sell a form tap that small? That would be my first choice. You'd want to do a couple practice holes in as similar material you can find in order to get the hole size right. Do the threads have to be gauged or is it OK as long as the screw goes in and doesn't strip immediately?

 

[Mike1974]

Does anyone sell a form tap that small? That would be my first choice. You'd want to do a couple practice holes in as similar material you can find in order to get the hole size right. Do the threads have to be gauged or is it OK as long as the screw goes in and doesn't strip immediately?

Balax makes one. Go their website and look for a retailer. We give their part number to our MSC rep and they purchase for us. we recently did some in half hard brass, cut tap though, worked fine, flood coolant.

 

[Mike1974]

Hard gold or soft? If it's hard gold, make sure your chamfer is big enough to remove the gold plate where the tap will be cutting, ie a bit larger diameter than nominal thread size.

 

[SShep71]

@AJ H: I had thought about doing EDM but the turn around time and cost is going to be the biggest hold up. I was quoted $300.00 a hole for small one off work like this in the past.

@rklopp: No need for a gauge or go/no-go this is a one time/one piece part that a copper 18gauge wire needs to securely fasten to. The existing coating is gold for conductivity and I would need to ensure there is no damage to the gold coating.

@Mike1974: I have found several companies that offer the tap size and die as well as I will need both. I do not know what gold content or RC it comes in at it is an aerospace electrical connector.

 

[kenton]

I second the form tap, use a tap guide and run it in by hand.

As an alternitive, is there a reason it couldn't be soldered? I ass-u-me that you are tapping the pin and threading the wire. Could you drill a clearance hole in the pin, flux the wire, and heat the pin in a fixture on a hot plate. Insert the wire when the pin is at temp and sweat some solder in.

 

[pavt]

Watch and clock makers probably do stuff like that routinely --

 

[jim rozen]

1) how deep does the tapped portion of the hole need to be?

2) size the tap drill size generously.

3) use a good cutting fluid. DO NOT USE A LUBRICANT for this.

If the hole is less than 1/32 inch deep you will have no problems.