Coolant hose for Boxford lathe

[Guineafowl]

Looking for a decent segmented coolant hose for the AUD, I found this:

RS PRO 1/4in Starter Kit | RS

uk.rs-online.com

Comes with either 1/4” or 1/8” NPT male connector.

Lathe has a 5/16” OD pipe, so I need a 5/16” OD - 1/4” NPT female adapter. Can’t find any, nor anything with a 1/4” NPT female end. Seems to be a USA standard. Any suggestions?

 

[Bsmith]

If it measures 5/16 across the diameter it will probably be 1/8" bsp or npt.
1/4" BSP will screw on 1/4" NPT especially with it being plastic.
I had one of these flexi pipes of eBay, it diddn't come with all the nozzles that are advertised on your ad but it was a fraction of the price and came to me from Singapore.

 

[Bsmith]

Durable Water Oil Coolant Round Lathe Pipe Plastic 1Pcs 30cm CNC Coolant | eBay

Find many great new & used options and get the best deals for Durable Water Oil Coolant Round Lathe Pipe Plastic 1Pcs 30cm CNC Coolant at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

 

[Guineafowl]

I saw some of those - they seemed too cheap. Thought they might dribble everywhere and break apart.

So, 5/16” OD to 1/4” BSP female needed? BSP or BSPT?

I hate finding pipe fittings. Such a timewaster.

 

[m_c]

MSC have genuine Loc-Line cheaper than RS - https://www.mscdirect.co.uk/LOC-40413M/SEARCH:CATEGORY/product.html
Personally having used various cheap options, I now always buy genuine Loc-Line from a reputable supplier, as the cheap stuff just isn't as good. Tolerances are rubbish, so it's either too tight, too slack, falls apart when you bend it too much, just doesn't come apart, and then you can't get the stuff back together.
Oh, and if you want to safe yourself from a world of pain, the pliers are a worthwhile investment - https://www.mscdirect.co.uk/LOC-78001D/SEARCH:KEYWORD/product.html

Full Loc-Line catalogue can be found at https://www.loc-line.com/files/catalog/Loc-Line.pdf


Is the 5/16" the measured diameter, or the thread size?
If it's the measured size, it would put it around 1/8"BSP or NPT

 

[Bsmith]

I saw some of those - they seemed too cheap. Thought they might dribble everywhere and break apart.

So, 5/16” OD to 1/4” BSP female needed? BSP or BSPT?

I hate finding pipe fittings. Such a timewaster.

I think the 1/8" female fitting will be the required size, ignore my previous comment about 1/4.

 

[Guineafowl]

Is the 5/16" the measured diameter, or the thread size?

Diameter of the plain pipe stub. A JG 5/16” push fitting, er, fits.

 

[Guineafowl]

MSC have genuine Loc-Line cheaper than RS - https://www.mscdirect.co.uk/LOC-40413M/SEARCH:CATEGORY/product.html
Personally having used various cheap options, I now always buy genuine Loc-Line from a reputable supplier, as the cheap stuff just isn't as good. Tolerances are rubbish, so it's either too tight, too slack, falls apart when you bend it too much, just doesn't come apart, and then you can't get the stuff back together.
Oh, and if you want to safe yourself from a world of pain, the pliers are a worthwhile investment - https://www.mscdirect.co.uk/LOC-78001D/SEARCH:KEYWORD/product.html

Full Loc-Line catalogue can be found at https://www.loc-line.com/files/catalog/Loc-Line.pdf


Is the 5/16" the measured diameter, or the thread size?
If it's the measured size, it would put it around 1/8"BSP or NPT

5/16 to 1/4 NPT male available from homebrew shop. MSC do 1/4 NPT female coupler which would work, but they’re out of stock. They also want £14 + VAT delivery for the coolant pipe.

There doesn’t seem to be a 5/16 to 1/8 BSP female coupler.

Did I say I hate finding pipe fittings?

 

[m_c]

Diameter of the plain pipe stub. A JG 5/16” push fitting, er, fits.

So it's probably had a 1/8" pipe fitting at some point.
I'd either look at threading the pipe, or for a suitable compression fitting.

 

[Guineafowl]

Here’s how it is at the moment. The original compression elbow, which broke, had rubber olives to provide some friction to hold the outlet in place, which is lacking in this JG replacement:



5/16” plain stub. If anyone can find me a connector from this to the male 1/4” NPT on segmented coolant lines, I’ll marry them.

 

[Agroshield]

One of these: https://www.ebay.co.uk/itm/111722414428 (1/8" BSP female to 1/4" NPT female £4.99)

Bore out BSP threads. Soft solder in solid piece of brass. When the solder has dried, bore out to 5/16" plain diameter. Loctite or soft solder onto end of silver pipe.

1/8" BSP has 8.6 minor diameter, so aralditing straight onto the stub would also work.

I'd need to know the size of the package before committing to any long term arrangement.

 

[m_c]

Another option is get a 1/8" die, thread the pipe, and screw on a coupler.

 

[Guineafowl]

One of these: https://www.ebay.co.uk/itm/111722414428 (1/8" BSP female to 1/4" NPT female £4.99)

Bore out BSP threads. Soft solder in solid piece of brass. When the solder has dried, bore out to 5/16" plain diameter. Loctite or soft solder onto end of silver pipe.

1/8" BSP has 8.6 minor diameter, so aralditing straight onto the stub would also work.

I'd need to know the size of the package before committing to any long term arrangement.

Now steady on…

Sounds like it would work, but a bit complex and I’d lose the swing-away movement (rotate pipe about vertical axis) that comes from a JG type fitting. You’re in the black book.

Another option is get a 1/8" die, thread the pipe, and screw on a coupler.

Ah, but which coupler?

 

[123hotchef]

you have a lathe cut a thread on the plain stub

 

[m_c]

Now steady on…

Sounds like it would work, but a bit complex and I’d lose the swing-away movement (rotate pipe about vertical axis) that comes from a JG type fitting. You’re in the black book.

Ah, but which coupler?

Female Female straight coupler like - https://www.ebay.co.uk/itm/403082202842

 

[Guineafowl]

Female Female straight coupler like - https://www.ebay.co.uk/itm/403082202842

You’re getting a taste of the afternoon I’ve had:

- ”Doesn’t post to Scottish Highlands”
- 1/8” BSP is 9.5mm, my stub is 7.9mm.

 

[m_c]

You’re getting a taste of the afternoon I’ve had:

- ”Doesn’t post to Scottish Highlands”
- 1/8” BSP is 9.5mm, my stub is 7.9mm.

Had it my head that the standpipe was 1/8" pipe size.
At 7.9, an 8mm compression fitting should work - https://www.midlandchandlers.co.uk/products/ag-female-coupling-1-8-bsp-to-8mm-compression-1-22460

 

[Agroshield]

...I’d lose the swing-away movement

I did wonder if the pipe stub swivelled in the top of the tap.

Screwfix 62371 will fit the 5/16" tube.

Same item number as before, https://www.ebay.co.uk/itm/111722414428 but choose 1/4" BSP female to 1/4" NPT female (£6.39). You will have to work out yourself how to make the Screwfix compression part swivel without leaking. 5/16" and 8mm are interchangable.

- 1/8” BSP is 9.5mm, my stub is 7.9mm.

1/8" BSP is 9.5mm MAJOR dia. A female BSP fitting will use the minor dia.

you have a lathe cut a thread on the plain stub

What thread? Or more precisely, what component could you buy with a 1/4" NPT female thread in one end of it and a 5/16" or 8mm female thread in the other end?

 

[Guineafowl]

BSP:

SIZE	TPI	MAJOR (EXT)	MINOR (INT)	TAP DRILL
1/8"	28	9.728	8.566	8.70
1/4"	19	13.157	11.445	11.60

NPT:

Outside Diameter D	Nominal Pipe Size	Threads per Inch (Pitch)	Thread Pitch Length, P	Pit...
0.3125	1⁄16	27	0.03704	0.2...
0.405	1⁄8	27	0.03704	0.3...
0.540	1⁄4	18	0.05556	0.4...

These don’t seem to match, so I’m not sure if BSP is the answer.

 

[Agroshield]

OK. Something that has a watertight swivel joint, with quick disconnect as a bonus.

Screwfix 62371 clamped solidly onto pipe
Screwfix 580KP threaded onto the 1/4" BSP thread above.
Screwfix 5763H plugged into female PCL fitting.
eBay 1/4" BSP F to 1/4" NPT F

That might work out well as you could swap the locline for a piece of rubber hose with male PCL coupler on it and shove it onto any through coolant boring bar you have.