View Full Version : Nylon tubing

03-07-2008, 02:32 PM
I'm in need of about ten feet of 4mm o.d. nylon tubing for the oil system on my Enco mill, but don't need to buy a 100 ft roll of it off of EvilBay, at $20+. Does anyone have some that they would care to sell? Thanks! :D

Montezuma, IA

03-07-2008, 03:17 PM
www.smallparts.com may have it by the foot.

03-07-2008, 03:31 PM
David...Look into Smallparts.com. They have that kind of stuff in small quantities and, although there is a $20 minimum purchase, there is all kinds of other stuff that you can't live without to fill in the order.

03-07-2008, 07:41 PM
Have you tried the local auto parts/racers supply store? That sounds close to the size that is used on a mechanical oil pressure gauge.


Rich Carlstedt
03-07-2008, 07:56 PM
is a great firm to deal with for any lubrication stuff.


I bought all my 4 mm tube from them when I couldn't find it locally.
I have no relationship with them, only a happy customer, because the guy on the phone was not concerned that I was not a 100 million dollar customer and wanted to help me.

03-07-2008, 07:56 PM
Try Reid Supply Co., no minimum. Don't forget new ferrules.

03-10-2008, 12:55 PM
At work we substitute 5/32" for 4mm tubing all the time. 4mm is .001" larger. The ferrules can easily take care of that. If you can't find 5/32" tubing locally, McMaster Carr has it.

03-10-2008, 01:42 PM
Thanks, Gents!

Montezuma, IA

03-10-2008, 03:24 PM
Electrical supply place nearby? I got some nylon covered solid core wire once and just removed the nylon. I don't recall what the original use for the wire was, but I used it for a hydraulic system using water. The diameter sounds about right.

03-10-2008, 04:03 PM
I would recommend using Tygon instead of Nylon. It's more flexible, crystal clear, doesn't absorb moisture and is proof against almost everything in existence including petroleum products. Small Parts has it in 5/32 at $2.25 for 10 feet.


03-10-2008, 04:14 PM
Tygon tubing will not handle the pressures nylon will. In a lube system, Tygon will simply baloon under pressure, and it will not dispense the lube properly.

03-10-2008, 04:29 PM
It's also commonly available in fabric reinforced type which will take any pressure nylon will. It's probably easier to find than nylon as it is used in a lot of food service applications such a liquor dispensers and soft drink systems.

03-10-2008, 04:45 PM
The reinforced tygon tubing will hold pressures in the 250-350 psi range, nylon tubing can be had rated over 1000 psi. The issue however has more to do with the rigidity of the nylon versus the flex of the tygon.

For a lube system to be effective, the lubricant must be dispensed to the various points. If a flexible tubing such as tygon is used, it will baloon, and distribution will be unequal. Copper is the first choice in these systems, nylon is next when flex is required in the operation, or for ease of installation. Tygon tubing is not used.

Nylon tubing is readily available from McMaster Carr and other sources.

03-10-2008, 04:52 PM
I've never seen Tygon tubing that small and its too soft for the application. 4MM is the O.D. of this stuff. One-shot lube systems use nylon because its tough, both directions. You can bend it fairly tight and it doesn't want to collapse on itself. This is an important feature as often the underside of say the saddle in a knee mill ends up with lots of the tubing in cramped quarters. It also must be able to resist compression forces as the compression fitting rings are squeezed into place. The nylon is perhaps more comparable to soft copper tubing--althought the crimp rings are ever so slightly different for the two. My mill had some of both...short, non flexible pieces in copper and the rest in nylon tubing.

I have bought this stuff from both Bijur ($35 minimum order however) as well as H&W Machine repair:


03-10-2008, 08:41 PM
The fabric reinforced Tygon won't balloon although it will expand slightly with pressure. If it does expand it won't:

A: reduce the pressure measurably.

B: It won't result in unequal distribution.

Pressure is pressure. The fluid will flow where the outlets allow it to go. The amount that comes out of each outlet is dependent on the total hydraulic resistance leading to and including the orifice of each outlet. A slight change in the internal diameter of the tubing makes no difference.

Small Parts recommends it for lubrication lines and not even the reinforced type.

Tygon Fuel and Lubrication Tubing is formulated to resist hydrocarbons and has a lower rate of permeation than competitive tubing. It resists the swelling and hardening caused by hydrocarbon based fluids which can lead to cracking and leakage. Its minimum extractability safeguards the liquid or vapor being transferred against contamination. Typical applications include small engine fuel lines, general automotive, lawn and garden equipment, coolant transfer, heating fuels, cutting compounds, and lubrication lines.

03-10-2008, 09:37 PM
Small Parts is merely selling a grade of tubing. Tygon tubing is acceptable for lube supply in single point applications and where it's only function is to move the lube from point A to point B.

In lube distribution systems, where the lube is metered under pressure to multiple points from a single source, nylon and copper are the materials of choice. Depending on system size and other requirements, other materials sometimes used are stainless braided, reinforced material, again to lend the necessary rigidity.

It is not a matter of reducing pressure, but it will result in unequal distribution due to the design of the system.

It is not a situation where the system is under a constant pressure. These systems meter an individual, measured shot usually on a timed cycle. There is a system of flow and pressure controls that proportion and direct that shot to the various points. These systems can be simultaneously feeding drip application points and pressure application points. If the tubing is ballooning and relaxing, the controls will not work properly and starvation of the points requiring pressure to apply will result.

03-10-2008, 09:48 PM
If the tubing is ballooning and relaxing, the controls will not work properly and starvation of the points requiring pressure to apply will result.

You will have to explain why that is so since there isn't any logical reason for it to be the case. Pressure is pressure, it doesn't matter what size the container is or if it changes size slightly when it is pressurized.

I wish you would do your homework before automatically disputing my suggestions or comments. If you don't think that Small Parts means lubrication lines when they say lubrication lines then talk to them and inform us please.

03-10-2008, 09:58 PM
Tygon is great tubing for water lines etc., we use it in the lab all the time. However, around organic solvents it leaches plasticizers and becomes hard and brittle. I've got one pc I use to syphon gas..not to rip anyone off although the though has occurred as the price of fuel approaches the cost of gold..and the end that has sat in the tank shrinks and becomes brittle.


03-10-2008, 10:11 PM
I have done my homework, and I have used, designed, installed and repaired many of these systems on many types of machines where lubrication is critical and failure is quite expensive. Shortcuts in materials are not taken in these instances for very good reasons.

I have no doubt that Small Parts means lubrication lines, and did not say they did not. However, they do not necessarily mean lubrication lines in these very specialized systems.

If anyone cares to read up on exactly how the systems work, I suggest they look into some of the manufacturer's literature. While I have tried to describe them simply, they are a bit involved as each system is tailored to the specific application.