Copper flathead screws and nuts

[JPT]

I need a small batch of copper 145 phillips flat head machine screws with nuts.


Material:
copper 145

Phillips flat head machine screw sizes:
4-40 x 1/2"
6-32 x 1/2"

Hex nut sizes:
4-40
6-32

Quantity:
This is a test, so I am flexible on the quantity.

I need a minimum of 10 each.

I have CAD files and PDF drawings available.

Thanks

 

[extropic]

Rather than Phillips recess, could you go with either slotted (easier = cheaper) or hex socket (easier than Phillips)?

Sanity check: What do you think is a reasonable price for your minimum lot?

 

[JPT]

If possible, I would prefer hex socket.

I can use slotted if absolutely required.


RE: reasonable price

This is for a test of conductive fasteners.

McMaster Carr charges $0.97 each for the 6-32 screws in aluminum, so that is a decent reference point for a conductive fastener.

$0.94 each 4-40 x 1/2" aluminum: mcmaster 97124A139

$0.97 each 6-32 x 1/2" aluminum: mcmaster 97124A239


The aluminum nuts are about $0.05 each.


They sell copper 145 rod:

1/4" 3' $15.32 mcmaster 9100K29

5/8" 1' $33.47 mcmaster 9100K15


So, ~$50 for materials, plus material shipping plus some reasonable amount for the time, labor, machine/shop overhead, etc., plus shipping the finished parts.


But, to be honest, I'm no expert at what to charge, as I am not in the job shop business.

 

[extropic]

Thanks for the reply.

"If possible, I would prefer hex socket." Make your options clear on your drawing to get your best price.


Material costs and shipping are inconsequential compared to the shop time.
Maybe somebody here has an NC lathe and a rotary broach and wants the work.
I only have manual machines so, IMHO, my price would be very unattractive to you.

Have you talked to any professional machine shops? My advice is to do so and get a real $$$$ number. Google "swiss screw machine" and find some people who will talk to you. If they don't want the work, ask for recommendations. Google "specialty fasteners in Texas". Fastener distributors deal with specials for a living.

It should become clear to you that the McMaster piece part prices are for commodity items competitively manufactured in HIGH quantities and not applicable to your 10 pieces each. Sanity check: Fail

A miracle could occur. Maybe somebody has some on the shelf.

Welcome to The Hobby-Machinist and good luck, really.

 

[JPT]

RE: specialty fasteners

I've been on this for a couple of months and have talked with all that I could find via Google, up to and including the mills in India that specialize in copper.

So, no known or reachable domestic or overseas suppliers are interested, willing, or able to take this on.

They deal in multiple metric ton quantities at the top end of the food chain and nobody further down the food chain produces this particular set of sizes and needs.

For all of them, this material and quantity doesn't make sense in their business model.


RE: manual machines

Agreed that this job is probably not a good fit.


RE: material costs are inconsequential compared to the shop time

Very much agreed


RE: on the shelf

That would indeed be a miracle.

 

[cbellanca]

Have you considered brass?

 

[benmychree]

Perhaps a redesign to fit available components.

 

[JPT]

RE: Brass

Thanks for the suggestion.

Brass is actually not very conductive.

Aluminum is pretty good.

Copper is best.

This is a test related to conductive fasteners.

 

[JPT]

Perhaps a redesign to fit available components.

Thanks for the suggestion.

The best available components that I've been able to find are aluminum for a machine screw and a copper rivet.

I'd like to test a copper 145 machine screw and nut, and thought that this would be a good place to find the available skills, equipment, and availability.

 

[JimDawson]

I'd like to test a copper 145 machine screw and nut, and thought that this would be a good place to find the available skills, equipment, and availability.

It is a good place, but it's going to cost a lot for some very small screws and nuts. They don't seem to exist.....Yet. For instance, my shop rate is $80 - $150/hr depending on what I am doing. And in this case I don't have the tooling to make exactly what you want. The real problem is the Philips or hex socket head. The threads are doable with standard tooling, but the head style you want requires some special tooling. A slotted head screw can be made with common tooling that many of us have.