EKINSUN LTD is a custom parts manufacturer that machines fittings and thread adapters to drawing, sample or photo: mixed-standard adapters, street elbows and tees with ports in different threads, bulkhead unions for a specific panel, push-in and compression bodies with a thread the series skips, check valve and gauge adapters for a pump or valve port, in brass, 304 and 316L stainless, steel and aluminium, from 1 piece. Standard fittings inside the ranges below are catalogue items that we also make to order from 1 piece; the chart tells the two apart in a minute.
A typical request: a G3/8 pump outlet, a 1/4 NPT gauge and a 10 mm push-in line that have to meet in one place, where every catalogue sells two of the three.
That is a tee with three different ports, and it is the shape of most fitting enquiries: each port is ordinary, the combination is not.
How to read the chart
Every row is one fitting form. Ports names the connections in order (M male thread, F female thread, tube, barb, panel). Standard is the number to put on an order where one exists; many tube and pneumatic fittings are maker series with no DIN or ISO number, and their two- or three-letter market codes (PC, PL, PE and so on) vary by maker and are aliases, not standards. Size range is what a distributor holds. Made to drawing when is the change that most often takes the part off the shelf. Page links to the family page with the full size table, the list of what is made to drawing, and the measuring routine.
- Thread sizes are nominal pipe sizes for G, R and NPT (a G1/4 male is about 13.2 mm across, not 6.35 mm) and thread diameters for metric; the identification chart has every value.
- Tube sizes are outside diameters: 6 mm tube is 6.0 mm, 1/4 in tube is 6.35 mm, and a push-in fitting for one does not grip the other reliably.
- Where a form is catalogued in brass and stainless the range given is the wider one; 316L, large sizes and mixed standards are the usual gaps.
Straight fittings and adapters
Straight fittings join two threads in line: male-to-male, female-to-female and male-to-female adapters in G, R, NPT, metric and UNF from G1/8 to G1, NPT 1/8 to 1 and M6 to M64; BSP-to-NPT and metric-to-imperial adapters from 1/8 to 1 in; bulkhead unions, hose barbs for 4–25 mm hose, banjo fittings M6–M16, plugs and caps, flange and tri-clamp adapters.
Need a straight fitting or adapter from this table in a size or thread pair the catalogue skips? Any row is made to order from 1 piece, standard sizes can also be supplied from stock, quote in 12 hours, delivered DDP. Get a price on WhatsApp · Quote form
| Type | Ports | Also called | Thread standards | Size range | Made to drawing when | Page |
|---|---|---|---|---|---|---|
| Male-to-male adapter | M × M | hex nipple, double male, reducing nipple | G, R, NPT, metric, UNF; mixed | G1/8–G1, NPT 1/8–1, M6–M64 | mixed standards, odd length, hex for a spanner, bore or restrictor | male-to-male adapters |
| Female-to-female adapter | F × F | coupling, socket, female union | G, Rc / Rp, NPT, metric | G1/8–G1, M6–M64 | two different threads, a depth the coupling does not have, a closed centre | female-to-female adapters |
| Male-to-female adapter | M × F | reducer, reducing bushing, enlarger, hex bushing | G, R, NPT, metric; mixed | G1/8–G1 in one-step reductions; M6–M64 | a two-step reduction, a mixed standard, a length or hex off the table | female-to-male adapters |
| Thread adapter, metric | M × F, M × M, F × F | gland reducer, sensor adapter | M10×1–M100 | M6–M64 in coarse and fine | any pair the tables skip | custom metric adapters |
| BSP to NPT adapter | M × F, M × M, F × F | G to NPT, BSPT to NPT | ISO 228 / ISO 7 to ASME B1.20.1 | 1/8–1 in | large sizes, stainless above 1 in, a body with a hex | BSP to NPT adapters |
| Metric to BSP or NPT adapter | M × F | metric to imperial adapter | metric fine to G / NPT / UNF | M10–M52 to 1/8–1 in | any pair | metric to imperial adapters |
| Bulkhead union | F × F through a panel, with jam nut | panel-mount fitting, tank fitting | G, NPT, metric; push-in and compression versions | 1/8–1 in; 4–16 mm tube | panel thickness, thread or length off the table, 316L | bulkhead fittings |
| Hose barb adapter | M or F × barb | hose tail, hose nipple | G, NPT, metric; barb to hose ID | 1/8–1 in; 4–25 mm hose | odd hose ID, metric thread, stainless, elbow or tee barb | hose barb adapters |
| Banjo fitting and bolt | banjo eye × hollow bolt | hollow bolt fitting, swivel banjo | M6–M16; G1/8–G1/2 | M6–M16 | odd thread, double banjo, restrictor bore | banjo bolts |
| Plug and cap | M plug; F cap | hex plug, socket plug, blanking plug | G, NPT, metric (DIN 906 / 908 / 910) | 1/8–1 in; M8–M36 | a plug with a magnet, a bleed, an O-ring seat or an odd thread | sealed metal parts |
| Flange adapter | flange × thread | flange to pipe, SAE flange | SAE J518, DIN, custom bolt patterns | to drawing | any bolt pattern | flange adapters |
| Tri-clamp adapter | clamp ferrule × thread or barb | sanitary clamp adapter | ISO 2852 / DIN 32676 ferrules | 1/2–4 in | ferrule to any thread | tri-clamp adapters |
Found the fitting type, but not in your thread pair or size? EKINSUN is a custom parts manufacturer: we make that fitting in your thread pair to your drawing, sketch or sample — brass, steel, 304 or 316L stainless steel — from 1 piece, quoted in 12 hours and shipped duties paid. Standard sizes can often be supplied from stock; the more pieces, the lower the unit price. All custom adapters and fittings →
Elbows
Elbows turn a line through 90° or 45° between two ports: threaded street, female and male elbows in G1/8–G1 and NPT 1/8–1, push-in elbows for 4–16 mm tube, compression elbows for 4–16 mm PU or 6–42 mm metal tube, hose barb and banjo elbows.
Need an elbow from this table in a thread pair or angle the catalogue skips? Any row is made to order from 1 piece, standard sizes can also be supplied from stock, quote in 12 hours, delivered DDP. Get a price on WhatsApp · Quote form
| Type | Ports | Also called | Standard | Size range | Made to drawing when | Page |
|---|---|---|---|---|---|---|
| Street elbow, 90° | M × F | male-female elbow, 90 degree adapter | EN 10241, ASME B16.11, brass EN 1254 forms | G1/8–G1, NPT 1/8–1 | mixed standards, reducing, a leg length that clears a wall, stainless above 1 in | threaded elbows |
| Female elbow, 90° | F × F | threaded elbow | as above | G1/8–G1 | reducing, 45°, metric | threaded elbows |
| Male elbow, 90° | M × M | double male elbow | maker series | G1/8–G1/2 | any pair | threaded elbows |
| Push-in elbow | tube × M or F, swivel | male elbow push-in, PL / PLF type | maker series | 4–16 mm and 1/8–1/2 in tube; M5, G1/8–G1/2, NPT | a thread the series skips, a metric-fine port, stainless body | push-in fittings |
| Compression elbow | tube × M or F with nut and ferrule | screw-lock elbow, quick-screw elbow | DIN 2353 / ISO 8434-1 for metal tube; maker series for PU tube | 4–16 mm PU; 6–42 mm metal tube | a port thread the series skips | compression fittings |
| Hose barb elbow | barb × M or F | elbow hose tail | maker series | 1/8–3/4 in | odd hose ID or thread | hose barb adapters |
| Banjo elbow | eye × bolt | swivel elbow banjo | maker series | M6–M16 | restrictor, double banjo | banjo bolts |
Tees, Y fittings and crosses
Tees, Y fittings and crosses join three or four lines: female (FFF), male-female-female (MFF), female-male-male (FMM) and reducing tees in G1/8–G1 and NPT 1/8–1, push-in tees and Y fittings for 4–16 mm tube, compression tees for 4–42 mm tube, and crosses in G1/4–G1/2.
Need a tee, Y or cross from this table with mixed threads or an odd size? Any row is made to order from 1 piece, standard sizes can also be supplied from stock, quote in 12 hours, delivered DDP. Get a price on WhatsApp · Quote form
| Type | Ports | Also called | Standard | Size range | Made to drawing when | Page |
|---|---|---|---|---|---|---|
| Female tee (FFF) | F × F × F | threaded tee, equal tee | EN 10241, ASME B16.11, brass forms | G1/8–G1, NPT 1/8–1 | reducing branch, mixed standards, metric | threaded tees |
| Male-female-female tee (MFF) | M × F × F | one male two female tee, branch tee, gauge tee | maker series | G1/4–G3/4 | the run or the branch in another size or standard | threaded tees |
| Female-male-male tee (FMM) | F × M × M | one female two male tee | maker series | G1/4–G1/2 | any port combination | threaded tees |
| Reducing tee | F × F × F, branch smaller | reducing branch tee | EN 10241 / ASME B16.11 forms | G1/4–G1 with one-step branch | two-step reduction, metric branch | threaded tees |
| Push-in tee | tube × tube × tube; or M × tube × tube | union tee, male branch tee, male run tee, PE / PB / PD type | maker series | 4–16 mm tube; M5, G1/8–G1/2 | a thread or tube size the series skips | push-in fittings |
| Y fitting | tube × tube × tube | Y union, Y branch | maker series | 4–12 mm tube | reducing Y, threaded Y | push-in fittings |
| Cross | four ports | four-way connector, cross union | EN 10241 forms; maker series for push-in | G1/4–G1/2; 4–12 mm tube | mixed ports, a cross machined from square bar | threaded tees and crosses |
| Compression tee | tube × tube × tube with nuts and ferrules | screw-lock tee | DIN 2353 forms; maker series for PU tube | 4–16 mm PU; 6–42 mm metal | a branch thread the series skips | compression fittings |
Tube fittings, check valves and instrument connections
Tube fittings connect 4–16 mm pneumatic tube or 3–42 mm metal tube to a threaded port: push-in studs with M5, G1/8–G1/2 or NPT threads, quick-screw and 24° cone compression fittings, twin-ferrule instrument fittings, inline check valves in G1/8–G1/2, and gauge adapters in G1/8, G1/4, G3/8, NPT 1/4 and M20×1.5.
Need a tube, check-valve or instrument fitting from this table in a non-catalogue size? Any row is made to order from 1 piece, standard sizes can also be supplied from stock, quote in 12 hours, delivered DDP. Get a price on WhatsApp · Quote form
| Type | Ports | Also called | Tube range | Thread options | Page |
|---|---|---|---|---|---|
| Male straight push-in | tube × M | male stud fitting, PC type | 4–16 mm; 1/8–1/2 in | M5, M6, G1/8–G1/2, R, NPT 1/8–1/2 | push-in fittings |
| Female straight push-in | tube × F | PCF type | 4–16 mm | G1/8–G1/2, NPT | push-in fittings |
| Union, reducing union, bulkhead union push-in | tube × tube | PU, PG, PM type | 4–16 mm; 1/4–1/2 in | — | push-in fittings |
| Speed controller | tube × M with a needle | flow control fitting | 4–12 mm | M5, G1/8–G3/8 | push-in fittings |
| Quick-screw compression fitting for PU tube | tube × M or F with a nut | screw-lock fitting | 4–12 mm | M5, G1/8–G1/2 | compression fittings |
| 24° cone tube fitting | metal tube × M with cutting ring | DIN 2353 L / S series | L 6–42 mm; S 6–38 mm | metric fine port threads | compression fittings |
| Twin-ferrule instrumentation fitting | tube × M or F, two ferrules | instrument tube fitting | 3–25 mm; 1/16–1 in | NPT, G, metric | compression fittings |
| Check valve, inline | M × F, M × M, F × F; tube × tube | non-return valve, one-way valve | G1/8–G1/2, NPT; 4–12 mm tube | — | pneumatic check valves |
| Gauge adapter and gauge tee | M × F; M × F × F | pressure gauge fitting, gauge connector | G1/8, G1/4, G3/8, NPT 1/4, M20×1.5 | — | pressure gauge adapters |
| Valve and pump port adapter | M × F, M × M, elbow, tee | valve adapter, pump inlet / outlet adapter | G1/4–G1, NPT, metric | — | valve fittings · pump fittings |
Thread standards on fittings
Eight thread standards cover almost every fitting: G (BSPP, ISO 228-1) parallel and sealing on the face, R / Rc / Rp (BSPT, ISO 7-1) tapered and sealing on the thread, NPT (ASME B1.20.1) tapered at 1:16, metric fine ports (ISO 6149 / DIN 3852) sealing with an O-ring, UNF / JIC 37° flare (SAE J514), ORFS (SAE J1453), SAE ORB (SAE J1926) and pneumatic mini threads M3–M6.
Need a fitting that joins two of these thread standards? Any row is made to order from 1 piece, standard sizes can also be supplied from stock, quote in 12 hours, delivered DDP. Get a price on WhatsApp · Quote form
| Standard | Number | Form | Sizes | Seals by |
|---|---|---|---|---|
| G (BSPP) | ISO 228-1 | parallel, 55° | 1/8–2 in | washer, O-ring or bonded seal on the face |
| R / Rc / Rp (BSPT) | ISO 7-1 / EN 10226 | R male taper, Rc female taper, Rp female parallel; 55° | 1/8–2 in | on the thread, with tape or sealant |
| NPT / NPTF | ASME B1.20.1 / B1.20.3 | taper 1:16, 60° | 1/8–2 in | on the thread; NPTF dry-seal |
| Metric fine port | ISO 6149 / DIN 3852 | parallel, 60° | M10×1–M48×2 | O-ring or bonded seal on the face |
| UNF / JIC 37° | SAE J514 | parallel, 60°, 37° flare seal | 7/16-20 (-4) to 1-7/8-12 (-24) | metal-to-metal flare |
| ORFS | SAE J1453 | parallel, 60°, O-ring face | 9/16-18 (-4) to 2-12 (-24) | O-ring in the face groove |
| SAE ORB | SAE J1926 | parallel UN / UNF, O-ring boss | 7/16-20 (-4) to 1-5/16-12 (-16) | O-ring at the boss |
| Pneumatic mini threads | ISO 16030 for M5 | M3, M5×0.8, M6×1, 10-32 UNF | M3–M6 | O-ring or gasket |
Diameters, pitches and threads per inch for every size are on the fitting thread identification chart.
Where the fitting catalogue stops
A standard elbow, tee, nipple, coupling or bushing in one thread standard, or a push-in or compression fitting in a catalogue tube size and thread, is a catalogue part; a fitting with ports in two or three different standards, a length, hex or bore that clears a specific obstacle, a body in 316L, titanium or PEEK, a push-in or compression body with a thread the series skips, or a fitting known only from a broken sample is machined from 1 piece.
| What you need | In the catalogue? | What we make |
|---|---|---|
| A standard elbow, tee, nipple, coupling or bushing in one thread standard, inside the ranges above | Yes | Buy it from stock, or have it made to order from 1 piece; no one-off competes on price with a forged or cast catalogue fitting. Standard parts: ask us too — we may have them in stock. |
| A push-in or compression fitting in a catalogue tube size and thread | Yes | Standard in the maker series: buy it, or have the body made to order from 1 piece. The codes on the box are aliases and vary by maker. |
| Two or three ports in different standards — G on one leg, NPT on another, metric on the third | No | Machined from hex or square bar with each port cut to its own standard, from 1 piece. |
| A standard form in a length, hex, bore or leg that clears a specific obstacle | No | Machined to the dimensions; the ports stay standard. |
| A body in 316L, titanium, PEEK or a brass grade the catalogue does not carry | No | Same geometry, your material. |
| A push-in or compression body with a thread the series skips — M14×1.5, M22×1.5, 3/8 NPT on a 4 mm port | No | Body machined to the thread; release ring or nut and ferrule fitted from the series — see push-in fittings. |
| A fitting with an O-ring groove, a sealing shoulder, a restrictor bore or a bleed | No | Machined; see sealed metal parts. |
| A fitting you only have a broken sample or a photo of | No | Measured and reproduced — see replacement fittings from a sample. |
Materials across the chart
Brass CW614N is the default fitting material for air, water and oil; 304 and 316L stainless cover marine, chemical and washdown lines; carbon steel covers hydraulic fittings; aluminium 6061 and 7075 make light pneumatic bodies and manifolds; POM, PA and PEEK form release rings, collets and chemical-service bodies; seals are NBR, EPDM, FKM or PTFE.
| Material | Designation | Where it fits here |
|---|---|---|
| Brass | CW614N (CuZn39Pb3) / C36000 for machined bodies; CW617N forged forms | the default fitting material for air, water and oil at moderate pressure; nickel plated on request |
| Stainless 304 | 1.4301 / A2 | standard stainless fittings in the common forms |
| Stainless 316L | 1.4404 / A4 | marine, chemical and washdown; machined where the catalogue stops |
| Free-machining stainless | 303 / 1.4305 | custom turned bodies where corrosion duty allows |
| Carbon steel | zinc plated or phosphated | hydraulic and structural fittings |
| Aluminium 6061 | AlMg1SiCu | light pneumatic and vacuum bodies, anodised |
| Aluminium 7075 | AlZn5.5MgCu | machined manifolds and high-strength light bodies |
| Engineering plastics | POM, PA, PEEK | release rings and collets; PEEK bodies for chemical service |
| Seals | NBR, EPDM, FKM, PTFE | O-rings, bonded washers, PTFE rings |
A real job of this kind: 8 Brass Fitting Variants with Non-Standard Thread — eight brass fitting variants with non-standard threads, machined from sample parts for a US distributor in 18 days.
Related pages
- Custom thread adapters — the hub for every thread pair
- how to identify a fitting thread — diameters, pitches and seals for G, R, NPT, metric, JIC and ORFS
- Thread adapter types — which of the three forms to order
- Hydraulic adapters — JIC, ORFS and high-pressure fittings
- Stainless steel connectors — 304 and 316 fittings
- panel and tank bulkheads — fittings that pass through a panel or tank wall
- replacement fittings from a sample — when the fitting is obsolete and only the broken one is left
- brass pipe fittings — the brass forms for equipment water and air lines
- CO₂ cylinder adapters and argon and nitrogen cylinder adapters — gas-cylinder valve threads to a regulator or an NPT port
- fastener types chart — the same chart for nuts, bolts, washers and pins
Frequently asked questions
They are all two-port straight fittings named by their ports: a nipple has two male threads, a coupling two female threads, a bushing a male outside and a female inside (usually reducing), and adapter is the general word for any of them when the two ports differ in size or standard.
One male thread and one female thread. Tees are written with three letters in port order, so an MFF tee has one male and two female ports and an FMM tee the reverse; the chart uses the same notation throughout.
No. They are market codes used by several makers for male straight, male elbow and union tee push-in fittings, and the letters vary between makers. Order a push-in fitting by tube outside diameter and thread, and treat the code as an alias.
Any form in the chart whose ports, length, material or seal are not a standard combination: mixed-standard tees and elbows, reducers with two steps, bulkheads for a specific panel, push-in and compression bodies with an odd thread, check valve and gauge adapters for a particular pump or valve port, and any fitting you only have a sample of.
EKINSUN LTD is a custom parts manufacturer that machines adapters, elbows, tees, bulkheads, barbs, tube-fitting bodies and check valve adapters to drawing, sample or photo in brass, 304 and 316L stainless, steel and aluminium, from 1 piece, with a quote within 12 hours.
There is no list price; the drivers are material, the number of ports and operations, and quantity. A brass reducer in an odd pair is a few minutes of lathe time; a 316L tee with three standards is a milled and drilled part and priced as one. Where a standard fitting would do, the quote says so.
Send the ports, in order
Each port: male or female, thread standard and size, or tube OD; the leg length or hex if it matters; material; quantity. A photo of the parts it must join works. From 1 piece, quote within 12 hours.
Not sure of the thread? Tell us four things: what the fitting connects to (pump, valve, gauge, cylinder, tube or hose); whether the port is the inlet or the outlet; which way the flow must go; and the tube outside diameter, not the hose bore, unless it is a barb. A photo with a caliper across the thread answers most of it.