
Fitting
High Rotary Joint
Push-in fitting joint best suitable for high-speed swiveling and swinging connections.
Advantages
Push-in fitting joint best suitable for high-speed swiveling and swinging connections.
By employing two ball bearings, suitable for high-speed swiveling and swinging connections where the Rotary Joint cannot cover.
Also effective in reducing load on moving parts and preventing tube twisting.
Specifications
| Fluid medium | Air |
|---|---|
| Max. operating pressure | 1.0MPa |
| Max. vacuum | -100kPa |
| Operating temp. range | 0~60℃(No freezing) |
Port size
Tube dia.
| mm size (mm) | φ4, φ6, φ8, φ10, φ12 |
|---|---|
| inch size | φ5/32", φ3/16", φ1/4", φ5/16", φ3/8", φ1/2" |
Thread size
| Metric male thread | M5x0.8, M6x1 |
|---|---|
| Taper pipe male thread | R1/8, R1/4, R3/8, R1/2 |
| Taper pipe female thread | Rc1/8, Rc1/4, Rc3/8, Rc1/2 |
| UNF thread | 10-32UNF |
| NPT thread | NPT1/8, NPT1/4, NPT3/8, NPT1/2 |
Construction

Type & Price list
Detailed Safety Instructions
Caution
1.High Rotary Joint series can bear a certain amount of radial load. However it may reduce the lifetime of the product. Be sure to verify the resistance when the load is large.
2.Use polyurethane tube for the high rotation applications. Hard tubes like nylon base may cause radial load to the fitting.
3.Tightening with excessive torque may cause a deformation of the metal hexagonal-column, leading a poor rotation or a fluid leakage.
Frequently Asked Questions for Fitting Series
PISCO Push-in Fitting allows for some leakage. With an oil-free specification, more apparent leakage could occur.
Since oil-free spec. products do not use oil for lubrication, the rubber parts do not slide, leaving the possibility of leakage due to deformation caused by friction resistance.
Try the following countermeasures if there is a leakage. If the problem persists, please contact PISCO sales office in your region for assistance.
Countermeasure 1
Disconnect the tube and cut its tip, then put the tube back into Push-in Fitting.
Also, applying a liquid that does not affect usage, such as water, to the tip of the tube during insertion may reduce friction resistance. Consequently, less deformation can be expected.
Countermeasure 2
Disconnect the tube and blow air into the fitting as some foreign substances may have adhered to the sealing parts (Elastic Sleeve).
Exercise extra caution when using a liquid as a fluid medium or in an environment where leakage is not permitted.
The hex wrench may have interfered with the tip of the lock claws during insertion, which could have caused the roll-off (tip deformation and loss of grip) of lock claws.
Roll-off of lock claws
Good lock claws
The rolled-off lock claws are less likely to grip a tube and could cause the tube to come off. Hard tubes (such as Nylon Tube and Fluoropolymer Tube) are more prone to coming off.
When installing POC fitting, fully insert a hex wrench into the inner hexagonal socket of the fitting and turn it.
No good: Over-sized hex wrench
Good: Hex wrench in adequate size
If NBR (nitrile rubber) is used in seal rubber or vacuum pads, ozone-induced cracks may occur and cause the product in use of those parts to malfunction. (Ozone cracks)
Ozone cracks will form perpendicular to the stress orientation (the direction of forces such as tensile stress).
Illustration of ozone cracks
Example of ozone cracks in nitrile rubber (NBR)
An oil-free specification is unlikely to provide effective oil film protection on the surface, which increases the likelihood of major ozone cracks.
Sources of low-concentration ozone typically include equipment utilizing ultraviolet light or electrical discharge principles (such as cleaners, static eliminators, and air purifiers), motors, and dry air compressors. However, ozone concentration and generation frequency are not constant, and the degree of impact varies.
HNBR and FKM (fluorine rubber) are good ozone resistant materials.
For your consideration, we have low-concentration ozone resistant products utilizing HNBR or FKM (fluorine rubber) in the seal rubber, for some as options.
Body sizes of 10 Series are bigger than those of 8 Series even with the same fitting (applicable Tube O.D.) and thread sizes. (Fig. 1)
Additionally, they have a different selection of fitting (applicable Tube O.D.) and thread sizes.
*In the case of AKC
<8 Series> Tube O.D.: φ6 and φ8, thread size: R1/8, R1/4
<10 Series> Tube O.D.: φ8 to φ12, thread size: R1/8 to R1/2
Fig. 1. Tube O.D.: φ8, thread size: R1/8
The plug (fitting part) and the socket (thread part) can be uncoupled. However, those parts are not interconnectable with other series. (Fig. 2)
Fig 2.
Two different types are available. One has a built-in stop valve on the plug side, which prevents an ejection of fluid from the fitting side when uncoupled.
The standard type without a built-in stop valve (AK) and the built-in stop valve type (AS) are both available in 10 Series. However, AK and AS types cannot be coupled because the shapes of the socket and plug differ.
Basically, you can use any tube fitting from any series as long as the tube diameter is right.
*For Compression Fitting series, both the tube O.D. and tube I.D. must be applicable.
Please check the specification and characteristics of each tube fitting and tube such as fluid medium, maximum operating pressure, operating temperature range, materials of parts and so forth to select the most suitable ones for your applications.
Example: For Tube Fitting PL6-01, a tube with Φ6 mm O.D. (UB0640..., NA0640..., etc.) is suitable.
Please utilize a search feature on the product list page of PISCO website to narrow down the suitable product by specifying detailed conditions such as specifications, characteristics, and materials of parts, etc.
If the tube diameter doesn’t match, we have a reducer, which we call "Unequal Plug-in Straight" (PGJ), that can change the tube diameter to fit a tube fitting of your choice. Please contact PISCO sales office in your region for details.
Also, please keep in mind the following.
<Cautions>
Since the flame-retardant outer cover of Anti-spatter Tube must be peeled off the tip for connection, the outer diameter (O.D.) of the inner tube, not the inner diameter (I.D.), is specified in the Model Designation.
Although the tube O.D. will be larger with the flame-retardant cover included, please select the tube fitting based on the O.D. of the inner tube.
Example: For FB0640-20, choose a tube fitting with an applicable tube O.D. of Φ6 mm (such as KC6-01).
*Be sure to peel off the outer cover when inserting the tube into the tube fitting. Otherwise, the tube may burst.
FB0640-20
When inserting Vacuum Tube (UD) into Push-in Fitting (excluding Minimal Fitting and Compression Fitting), be sure to use Insert Ring.
The materials used are in the table below.
| Series | Model code | Nut Material |
|---|---|---|
|
Tube Fitting Standard |
PM16, PMF16 |
Nickel plated brass |
|
Tube Fitting Standard |
PMP□, PML□ |
Aluminum |
|
Tube Fitting Standard |
Other than the above |
Trivalent chromate carbon steel |
|
Tube Fitting Mini |
PM3M, PM4M, PM1/8M |
Nickel plated brass |
|
Tube Fitting Mini |
PM6M. PM1/4M |
Trivalent chromate carbon steel |
|
Tube Fitting SUS316 |
SSPM□ |
SUS316 |
|
Tube Fitting Stainless SUS303 Equivalent Corrosivity |
SPM□ |
Special stainless steel (SUS303 equivalent corrosivity) |
|
Tube Fitting PP SUS304 |
PPMP□ |
SUS304 |
|
Tube Fitting PP SUS303 Equivalent Corrosivity |
SPPMP□ |
Special stainless steel (SUS303 equivalent corrosivity) |
Yes, certainly. You can order just Bulkhead Nut. Please check the model codes in the table below.
If you cannot find the product you are looking for, please contact PISCO sales office in your region for assistance or contact us via the inquiry form.
(1) and (2) in the model code of Bulkhead Nut indicate the following: (1) the major diameter from the bulkhead thread size (from the "M" column of the outline dimension table under Dimensional Drawing on PISCO website product pages) and (2) the thread pitch.
*Outline dimension tables are on PISCO website brief product summary pages.
(Accessing a type such as "Bulkhead Union PM" via the link on PISCO website product page will take you to its brief product summary page.)
For more information, please check the example illustrated below the table.
| Product series | Used for | Model code of Bulkhead Nut |
|---|---|---|
|
PM16, PMF16 |
PM16: MN28P1.5 |
|
|
PM and PMF other than the above |
MNF(1)P(2) |
|
|
PMP, PML |
MN(1)P(2) |
|
|
PM3M, PM4M, PM1/8M |
MN(1)P(2) |
|
|
PM6M, PM1/4M |
MNF(1)P(2) |
|
|
LM-FM5 |
MN10P1 |
|
|
SSPM NSMC, NSM, NSMF, NSMFF |
SMN(1)P(2) |
|
|
SPMF, SPM, SPML |
MN(1)P②-SP |
|
|
PPMP |
MNP(1)P(2) |
|
|
KM |
MN(1)P(2) |
|
|
NKMF |
MN(1)P(2) |
|
|
PSM |
PSM4M-4: MN10P1 |
|
|
MKR |
MNF(1)P(2) |
|
|
CPSE3M-4, CPSE7M-6 |
CPSE3M-4: CPS340M02NI |
|
|
BVM, BVLM |
MNF(1)P(2) |
|
|
BVM, BVLM |
MNF(1)P(2) |
[Example] PM6
Brief product summary page
Digital Catalog
Even with the same tube size, the bulkhead thread sizes (M) will differ depending on the product.
Please refer to the outline dimension table of your preferred product.
Yes, it is rotatable. After tightening the thread, you can manually rotate the resin body to adjust the tube pull-out position.
*Any tube fitting with a resin body joined by a metal part can be rotated.
*You cannot use it for continuous rotation.
A hexagon head of PH type or a hexagonal hole of POL type on each top should be tightened with a wrench or hex wrench.
For continuous rotation, please select Rotary Joint or High Rotary Joint.
The related FAQ
Except for SUS316 Compression Fitting and All Brass Compression Fitting, almost all Elbow type PISCO tube fittings swivel at the joint.
(The joint between the thread and the fitting body allows for swiveling.)
"Swivelling" in this case means that the joint can be manually rotated to adjust the tube pull-out position after tightening the thread. If you need the tube fitting to rotate or oscillate along with the tube, use Rotary Joint or High Rotary Joint with a built-in ball bearing.
Differences between Standard type tube fittings and Rotary Joint/High-Rotary Joint
The thread size code "N1" indicates NPT 1/8.
The wrench size of the metal body is usually designed in millimeters (mm).
"U" at the end indicates the wrench size designed in inches.
N1
The thread size is NPT 1/8, and the wrench size is in millimeters.
N1U
The thread size is NPT 1/8, and the wrench size is in inches.
Basically, the yellow release ring is only available as a special option of the "-D" (oil-free) or "-E" (EPDM for seal rubber) specification.
These codes indicate a change in specification from standard to special for packaging, lubricants, seal rubber materials, etc. These products will be made to order.
Please contact PISCO sales office in your region for the model codes.
Which of the effective sectional area, orifice diameter, sonic conductance, or flow rate is noted depends on the product's usage and characteristics. We are switching from effective sectional area notation to orifice diameter notation. Effective sectional area notation is still used for products prior to this change.
The design of PLL changed in November 2014 to reduce its weight.
Yes, we do. [Examples] PG1/4-6, PG1/4-4, etc.
We may have tube fittings in a combination of different sizes not listed in our catalogs. For details, please contact PISO sales offices in your region or submit an inquiry form on PISCO website.
We have tube fittings with boss holes that can be used for fixation if you have the necessary screws.
Please refer to the hole diameter and length of boss in the outline dimension table under Outline Dimensional Drawing on PISCO website product pages.
We also have fixing holders and mounting brackets for some products, which we hope you find useful.
This specification does not use copper-based materials, making it ideal for processes and operating environments where copper should be avoided.
For the "-S3 spec.", no copper-based materials are used for the metal parts, and the seal rubber material is HNBR or FKM. More specifically, we offer “-S3 spec.” products that use stainless steel for the metal parts in flow paths instead of brass.
"-S3 spec." may be available as standard rather than optional and not be indicated in the model designation.
(Ex.) Tube Fitting SUS 304: the metal body is SUS304, and the seal rubber material is FKM.
| Spec. | Classification | Intended use of lubricant oils during the assembly process | Processes after assembly to packaging |
|---|---|---|---|
|
Standard |
ー |
Turbine oil |
Products are packaged as they are after assembly |
|
Oil-free (-D) |
Lubrication specified |
None |
Oils are removed from assembly and packaging processes but not completely. |
|
Clean-room packaging (-C) |
Packaging specified |
Fluorine-based grease |
Products are packaged in a clean room equivalent to ISO class 6 after purified by clean air. |
|
Clean-wash (-UC) |
Packaging specified |
None |
Products undergo vacuum ultrasonic cleaning with HFE (hydro fluoro ether) in a clean-room, followed by deaerated packaging. |
We have G thread available with Tube Fitting Standard and Tube Fitting Mini.
For details, please see the following PDF.
G thread is also available with Vacuum Pad Holder.
Yes, we do. For details on inch and NPT specifications, please refer to the catalogs on PISCO website.
We have Hand Valve and Ball Valve, which are shut-off valves, to stop the air. We also have Cap (PPF) that plugs the tip of an unused tube.
Similar to PISCO Push-in Fitting, simply insert the tube into Cap. This will prevent airflow.
We have Plug (PP) for it.
Simply inserting Plug will do the job.
Yes, you can as long as the connection size of the two matches.
No, you cannot connect Plug and Socket in different connection sizes.
Please refer to the tightening torque table of each series in "Common Safety Instructions for Fittings" or "Common Safety Instructions for Vacuum Pad (Suction cup)" on PISCO website.
The range is 0 to 60℃, which is in line with that of PISCO tube fittings.
PISCO tube fittings with the model code ending with "M" are ultra-small push-in fittings from Tube Fitting Mini series.
They are not the same with standard tube fittings from Tube Fitting Standard series without "M" at the end of the model code.
Tube Fitting Mini is 40% smaller than Tube Fitting Standard. It is more compact, has a lower profile but cannot use water as a fluid medium.
These codes indicate a change in specification from standard to special for packaging, lubricants, seal rubber materials, etc. These products will be made to order.
-C
clean-room packaging spec.
-D
oil-free spec.
-E
EPDM (Seal rubber material)
-F
FKM [Fluorine] (Seal rubber material)
For details such as products available on a make-to-order basis, please check the following “Make to Order Production”
The official term used by ISO 14743 is "Push-in connectors for thermoplastic tubes". Push-in fittings are designed to connect a plastic tube for air piping. The tube can be securely connected by simply inserting it into the fitting. For disconnection, just pull the tube while pressing down the release-ring on the fitting.
Push-in fittings are applied in various ways, such as by incorporation into speed controllers or valves.
Since PISCO Push-in Fitting is designed to seal the tube’s outer diameter with an elastic sleeve (seal rubber), a several factors can cause leakage, such as scratches or deformation of the tube and jamming of contaminants.
After all, it is manufactured for use with pressurized air piping systems. It cannot be used in the circuits of gas or liquid that can pose a danger in the event of a leak, nor for inspection equipment that could easily be affected by the slightest leak.
To disconnect a tube from Push-in Fitting, please pull the tube while pushing Release-ring all the way down. If you are not accustomed to using Push-in Fitting, you may try pulling the tube before pushing the release-ring all the way down. If that is the case, the lock claws will still be biting the tube, making it difficult to disconnect the tube.
Watch the video at 1:07 when having trouble disconnecting a tube
PISCO Push-in Fitting is basically designed for use with resin tubes. Its metal lock claws moderately bite the tube’s outer diameter to secure the tube.
However, the lock claws cannot bite the outer diameter of a metal pipe (steel pipe). Consequently, their pull-out strength decreases significantly.
Although Push-in Fitting basically cannot be used with a metal pipe (steel pipe), some users create grooves on the outer surface of the metal pipe where the lock claws will bite. This allows the lock claws to fit and grip the grooves, fixing the pipe without losing their pull-out strength.
The standard PISCO Push-in Fitting withstands 30 million cycles in the fixed durability test, and 5 million cycles of oscillation movements in the dynamic durability test.
The fixed durability indicates the number of cycles that satisfies air tightness with no damage to any part when 0.7 MPa of air pressure is applied and released at a frequency of 2 cycles per second.
The dynamic durability indicates the number of cycles that satisfies the condition of the fixed durability test with oscillation movements at a frequency of 2 cycles per second.
We are occasionally asked to provide an answer in terms of service life (time). However, we cannot answer in years (or hours) since the product service life can vary substantially depending on the operating conditions.
The operating pressure is individually set by model. For the standard PISCO Push-in Fitting, it is 1.0 MPa.
Please be sure to check the specifications of each model as the operating pressure may change depending on temperature, such as Tube Fitting PP.
Since the maximum operating pressure indicated in the specifications is not the burst pressure, the tube fittings will not break immediately after more than the maximum operating pressure is applied. However, for your safety, please use them within the specifications. Please note that the warranty does not cover usage exceeding the specified maximum operating pressure.
Using PISCO tubes is basically recommended.
*Please see the question, "Are PISCO products compatible with tubes or tube fittings of other brands?”
Please make sure that the tube's cutting plane is right angled and three is no scratches, stain or foreign substances present on the tube.
Tubes for push-in fittings of other brands can basically be inserted into PISCO Push-in Fitting as long as the outer diameter matches (with some exceptions). That said, since PISCO Push-in Fitting is designed to seal around the tube (using seal rubber such as an elastic sleeve to seal the outer diameter of the tube), a tube with an imprecise outer diameter will be difficult to insert into or disconnect from the tube fitting or cause air leakage.
We recommend using PISCO tubes with PISCO Push-in Fitting series whenever possible.
When using tubes of other brands, please make sure that the outer diameter tolerances of tubes listed in the table below are met.
Tube O.D. Tolerance
| mm size | Nylon tubes | Polyurethane tubes |
|---|---|---|
|
φ1.8 mm |
― |
±0.05 mm |
|
φ2 mm |
― |
±0.05 mm |
|
φ3 mm |
±0.1 mm |
±0.15 mm |
|
φ4 mm |
±0.1 mm |
±0.15 mm |
|
φ6 mm |
±0.1 mm |
±0.15 mm |
|
φ8 mm |
±0.1 mm |
±0.15 mm |
|
φ10 mm |
±0.1 mm |
±0.15 mm |
|
φ12 mm |
±0.1 mm |
±0.15 mm |
|
φ16 mm |
±0.1 mm |
±0.15 mm |
| Inch size | Nylon tubes | Polyurethane tubes |
|---|---|---|
|
φ1/8 |
±0.1 mm |
±0.15 mm |
|
φ5/32 |
±0.1 mm |
±0.15 mm |
|
φ3/16 |
±0.1 mm |
±0.15 mm |
|
φ1/4 |
±0.1 mm |
±0.15 mm |
|
φ5/16 |
±0.1 mm |
±0.15 mm |
|
φ3/8 |
±0.1 mm |
±0.15 mm |
|
φ1/2 |
±0.1 mm |
±0.15 mm |
|
φ5/8 |
±0.1 mm |
±0.15 mm |
First, please check the product name (and if you have already made a choice, its model code). Also, check the proper name of the chemical to be used.
Then, check the chemical-proof properties of the materials used in your chosen product via the following link, "Chemical-proof properties".
You can refer to the sectional drawing of the product to see if the piping directions can be changed (the joint between the thread and the body allows for swiveling).
Please note that it is "rotatable" in the sense that the piping directions can be manually adjusted after tightening the thread. If you need the tube fitting to rotate or oscillate along with the tube, please use Rotary Joint or High Rotary Joint with a built-in ball bearing.
In some cases, we will be able to manufacture a tube fitting with a combination of tube diameter and thread size not listed in our catalogs.
Please contact PISCO sales office in your region for details.
For PISCO Push-in Fitting, it is possible as long as the outer diameter of the tube is the same.
However for Barb Fitting and Compression Fitting, both the inner and outer diameters of the tube must match those of the tube fittings for connection.
Whether water is allowed depends on the model. For the standard PISCO Push-in Fitting, water can be used as long as the conditions are met. The following are the conditions to use water as a fluid medium.
1. Make sure that the surge pressure, which is the temporary increase in pressure when a valve is closed, remains at or below the maximum operating pressure.
2. General tap water in Japan is usable. Since other types of water may not meet our specifications in the same way, please evaluate PISCO products under actual operating conditions and decide whether to use them.
3. Use Insert Ring, a stainless steel insert that provides internal support for the tube.
Use of Insert Ring is recommended to prevent tube contraction. Prolonged water use in the tube can cause the tube to contract, making it prone to coming off or leaking.
Basically no.
A tube that is too soft to withstand being squeezed by one's fingers will be difficult to insert into Push-in Fitting. Even if it could be inserted, it would have low pull-out strength and could easily come off.
PISCO Vacuum Tube (UD) is an ultra-soft polyurethane tube that can be squeezed by one's fingers. However, it can be inserted into PISCO Push-in Fitting when used with Insert Ring (a stainless steel insert that provides internal support for the tube).
Basically we do not offer tube fittings for rubber hoses.
*Some models of Die Temperature Control Fitting can be used with heat-resistant hoses.
PISCO products are designed and developed for use in both positive and negative (vacuum) pressure environments.
Please be assured that PISCO Push-in Fitting can be used at negative pressure.
Most of PISCO tube fittings have a coating called "Sealock" around the thread parts. Therefore, you don't need to wrap the seal tape around the threads.
However, some products such as Tube Fitting SUS316 and Tube Fitting PP are not coated with Sealock. In these cases, you need to wrap a seal tape or apply a sealing compound that is suitable for your application.
Even for those Sealock-coated types, the coating will wear off after a couple of repeated thread tightening, which causes sealing deterioration. Please apply the same treatment as for the non-Sealock types as needed.
Rather than "Straight (PC)" type with an external hexagonal part that needs to be tightened with a wrench, "Inner Hex. Straight (POC)" type is better suited for tighter spaces because it has an internal hexagonal hole that can be tightened with a hex wrench.
Moreover, in this case, Tube Fitting Mini is smaller and more effective than Tube Fitting Standard.
If low profile is required due to limited installation space, we recommend Single Banjo (PH) type or Hex. Holed Banjo (POL) type rather than the standard Elbow (PL) type.
When the heights of ø6 mm x R1/8 sizes are compared, the standard Elbow type (PL6-01) is 33.55 mm, Single Banjo type (PH6-01) is 27 mm and Hex. Holed Banjo type (POL6-01) is 24 mm.
If the same combinations of connection size are available in Tube Fitting Mini series, they can be very effective candidates for space-saving also.
Height of Tube Fitting Mini Elbow type (PL6-01M): 22.25 mm
PISCO tube fittings are rich in variety
Watch the video at 2:00 for the height comparison of PL, PH, and POL
You can insert and disconnect multiple tubes simultaneously by using Connector.
A single unit of Connector can take two tubes for insertion/disconnection. If you connect multiple terminals vertically or horizontally using Connector Band, more tubes can be handled at a time.
We have Light Coupling series.
For compatibility with other brands, please contact PISCO sales office in your region.
For the hole size to be drilled in the panel, please refer to "M" in the outline dimension table under Outline Dimensional Drawing on PISCO website product pages. And "A" and "K" in the table for the thickness of the panel.
Example: Bulkhead Union PM4
"M" dimension is M12 x 1, which means the major diameter is 12 mm. However, please allow a small margin because drilling an exact 12 mm hole in the panel may cause the main body to get stuck or to have difficulty passing through.
The thickness of the panel equals dimension "A" (screw length) minus 2 times K (thickness of Lock nut)]. So in this case, it is 14.8 - (2 x 4), which equals 6.8 mm, the maximum thickness of the panel.
When installing the tube fitting in the panel hole, remove Lock nut first, pass the main body through the hole, then put back and tighten Lock nut to fix the tube fitting to the panel.
PISCO uses PTFE (polytetrafluoroethylene).
PTFE is a typical fluororesin used for water- and oil-repellent coatings on frying pans and other items.
Pure water and ultrapure water do not affect PISCO products. However, proper judgment is needed based on the application because some constituent materials of parts, oils applied to the products, or the additives used in the tubes could ooze out.
As to industrial water, how it affects the products is unpredictable. Please evaluate the water under actual operating conditions before making a decision on its use.
Do not use grey water and sewer water.
EPDM (ethylene propylene) rubber has superior resistance to heat, ozone, solvents, and inorganic chemicals. Conversely, it is not tolerant of general mineral oils, rendering it unsuitable for pneumatic circuits that use such oils.
However, this talk is limited to the general pneumatic circuits only. EPDM is the most suitable material for applications where the fluid medium is water.
Gaskets for metric threads included in PISCO products can basically be purchased in units of 10.
Our typical gaskets are made of NBR, FKM as a sealing material, or resins (PPS, POM).
Model codes differ depending on the product for which the gasket is used and its size. Please contact PISCO sales office in your region for details.
The following threads are primarily used for PISCO products.
(1) Taper pipe thread
PISCO model code example: PC6-01, etc.*
This type of pipe thread is mainly used for securing leak-resistant (airtight) connections.
It has a 55°included angle, tapers towards the end and is cone shaped.
Taper pipe threads of PISCO products are Sealock coated as standard. If Sealock is not used, the thread parts need to be either wrapped with seal tape or coated with other sealing compounds.
Indication example: R1/8 (Rc1/8)
It means "Taper pipe male (female) thread with the nominal diameter (size) of 1/8".
*) 1/8 is the nominal diameter, which is a standardized term to identify the outer diameter of the pipe. It does not imply 1/8 inches (3.175 mm).
(2) Metric thread
PISCO model code example: PC4-M5, etc.*
Metric thread is designed in metric dimensions and has a 60°included angle.
The two variations are available: "metric coarse thread" and "metric fine pitch thread", where the latter has a smaller pitch than the former.
By compressing the gaskets against the bearing surface, air tightness is secured.
PISCO uses metric threads mainly for small products.
Indication example: M5 x 0.8
It indicates "Metric thread, 5 mm thread diameter and 0.8 mm pitch".
*) PISCO uses metric fine pitch threads for Tube Fitting Mini, PCC Cartridge, Main Block, etc.
(3) Parallel pipe thread (G thread)
PISCO model code example: PC6-G1, etc.*
This type of pipe thread is mainly used for making a mechanical connection.
It has a 55°included angle and is in cylindrical/parallel form.
Similar to the metric thread, the thread itself does not provide an airtight seal. Air tightness is secured by compressing the gaskets against the bearing surface.
PISCO uses parallel pipe threads for Rotary Vacuum Pump and so forth
Indication example: G1/8
It indicates "Parallel pipe thread, 1/8 nominal diameter (size)".
(4) NPT thread (American National Standard Taper Pipe Thread)
PISCO model code example: PC5/32-N1U, etc.*
This is general-purpose taper pipe thread in the United States. NPT stands for "National Pipe Taper".
The thread is tapered, but the included angle, pitch, and nominal pipe size differ from those of (1) Taper pipe thread.
NPT threads of PISCO products are Sealock coated as standard. If Sealock is not used, the thread parts need to be either wrapped with seal tape or coated with other sealing compounds.
Indication example: (R)1/8-27NPT
It indicates "NPT 1/8 (male) thread size (nominal diameter), and 27 threads per inch (per 25.4 mm)".
(5) Unified fine pitch thread (UNF thread)
PISCO model code example: PC5/32-U10U, etc.*
This thread has a smaller pitch than the unified coarse thread (UNC thread) that is standardized and used in the United States, the United Kingdom, and Canada.
Indication example: No.10-32UNF
It indicates "UNF, No.10 thread size (nominal diameter), and 32 threads per inch (per 25.4 mm)".
About PISCO model codes
*The indication examples shown here (such as R1/8 and G1/8) cannot be used as they are in PISCO model codes.
PISCO uses "01" instead of "R1/8" for the thread size, meaning the actual PISCO model code will be "PC6-01". It is not "PC6-R1/8". Please make a note of it.
Please check our catalogs or website and fill in the model codes.
Tighten the resin-type thread by hand until it stops. Then, use a tool such as a wrench to retighten it two to three more turns.
If the resin-type thread is used for an extended period of time, it may loosen due to creep deformation and cause slight leakage. Therefore, regular inspections and retightening are necessary.
If retightening does not resolve the issue, please replace the product.
Tube Fitting SUS304 withstands air, water and other fluid medium.
Tube Fitting Stainless SUS303 Equivalent Corrosivity is less corrosion-resistant than Tube Fitting SUS304 and can be used for air and water only. However, it has a more affordable price.
Also, materials for the metal parts as well as seal rubber and Release-ring are different. Please select the one that best matches your application.
How the materials for Tube Fitting SUS304 and Tube Fitting Stainless SUS303 Equivalent Corrosivity differ.
How to identify Tube Fitting SUS304 and Tube Fitting Stainless SUS303 Equivalent Corrosivity
They look similar, but the groove markings on Guide ring and the hexagonal part are different, making them identifiable.
Inquiries about this product
It is also possible to suggest products suitable for various conditions such as applications and functions. Please feel free to contact us or visit the nearest sales office.
The following are frequently asked questions. Please check before making inquiries.


