Rookie with a Bridgeport... looking for some assistance.

Hello! I've been lurking around here a while reading in my spare time. First post today, looking for some advice from the much more experienced members here.

Background... I do my fare share of fab work in my garage. Custom parts for my car, BBQ grill, trailers, and quite a bit of stainless TIG for work related items. I have a nice tight Bridgeport that I play around with, a Walker Turner bandsaw, MIG, TIG, plasma, etc... I have some tooling for the mill, but I am in NO WAY a machinist. Rook-dawg looking to learn.

We have some parts at work I'd like to produce. Some pictures below.. These are high pressure junction blocks rated at 101,000 psi. They are made out of HP160 which I cannot seem to find anywhere. Its a special alloy for this industry - however I have some other parts that are rated for the same pressure made from 15-5 stainless.
HP160 has a tensile strength of 160,000 psi
15-5 in the H1025 condition has a tensile strength of 155ksi... pretty close. Rockwell is at C35 for this stuff.

Have a look at this part... I need to mill a flat bottom hole and thread it 3/4 - 16. Threads DO NOT have to go all the way to the bottom.
Also need to have the cone feature in the bottom that the high pressure tube seals into.

Any recommendations on how to produce this feature on my Bridgeport?
Can I thread a hole this size in C35 material using a Tapmatic?
Do I use an end mill and keep stepping up in size until I reach the correct diameter, or do I use my boring head?

Like I said, I have very little machining experience but would love to learn. With what we spend on these parts I could easily justify the purchase of a new HASS Mini... but I'd like to get started without dropping $35k on a machine.

Thanks for any input or advise!

There is a reason those part are so expensive. Enjoy the journey.

I think you mean 1000PSI....but heres what I would do...take some 4140 or 4340 and make the part....then heat treat it to C 35-40....that way you can machine it easier first....this is good to 1000PSI...so check that 100,000 psi number 1st...my 2c

Our machine runs at 87,000 psi... parts rated for 101k. That aint a typo.

No

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Joerags said:

Any recommendations on how to produce this feature on my Bridgeport?

Click to expand...

Buy the part.
Put it on the table of your bridgeport.



Curious: What is the application requiring 87,000 PSI? Water jet cutter?

What if your homemade part leaks at 87,000 PSI?
If the cost savings of DIY is greater than the consequences of a leak, go for it.

APD said:

Buy the part.
Put it on the table of your bridgeport.



Curious: What is the application requiring 87,000 PSI? Water jet cutter?

What if your homemade part leaks at 87,000 PSI?
If the cost savings of DIY is greater than the consequences of a leak, go for it.

Click to expand...

These parts are consumables... We typically see 8,000 to 10,000 cycles before they fail. The high pressure tubing does not last as long. If my "DIY" parts are not up to snuff - everything is substantially guarded. The part pop's, water goes everywhere and the cycle fails. Replace it and pressurize again.

That little block pictured is upwards of $400. Some others we purchase are $1700, hence my desire to start fabricating them in house.

John Welden said:

No

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Very constructive input. Thank you.

Gain some experience with your mill before you start making serious parts. Learn operational safety first until you don't have to think about it.

Looks familiar ...

If you cannot test it to certify it, you shouldn't be making it.

Have you tried pricing other suppliers?

High Pressure Fittings and Tubing | Parker Autoclave Engineers

Go for it! If it don't work pick up the phone and order one.
You learn by doing.

Part says made in Germany and has the China export "CE" on it ???

CE stands for Conformité Européene.

Cbcues said:

Part says made in Germany and has the China export "CE" on it ???

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WOW, who started that rumor?

I was under the impression that is what it stood for, I guess not.

What specs are on that thread and hole? I'd image the tolerance on the thread may drive you batty if you're a complete noob. Probably worth having a set of cycled thread gauges and regular calibration done on them.

May be worth farming the job out. Or pick up a used CNC to allow helical hole roughing(or custom order endmills and reamers to size), thread milling undersize and chase them with fresh high quality taps.

Joerags said:

Very constructive input. Thank you.

Click to expand...

…it actually speaks volumes…

Here's a cross section and some dims.

http://high-pressure-products.maxpr...0-000-psi-1-4-3-8-9-16-hp-connection-3/101l6u

How is your math? Can you calculate the material yield, pressure fracture, and ect? Do you have a method of testing your product? If not, you need to come up with a documented method of doing so. Once you do those task then your going to have to find a lic. Engineer to verify your results and put his name on it. You’ll need to out lay some bucks for that. I’m not saying you can’t do it... just know upfront there are some cost and processes you have to go through.

It would take a couple of pages of notes just get you started down the right path to make this product. But...it could be done. Note that all your competition has already done just this, that is why they charge what they do.

The critical part is not the flat on the bottom, rather the tapered hole, that is where the seal is made and needs to be nice. The nut that pulls the high pressure line tight shouldn't bottom out on that flat. I think you're going to have a lot of trouble making these, I have CNCs and lots of tooling and I still buy our fittings. Leave it to the guys that are set up and do this day in and day out.