EKINSUN LTD is a custom parts manufacturer that machines brass fittings to drawing: mixed-standard nipples and reducers, tees with a metric branch, extensions, elbows with a gauge port, barbs for an odd hose, plugs with a bleed, in free-cutting brass CW614N or dezincification-resistant CW602N, plain or nickel plated, from 1 piece; standard brass pipe fittings inside the ranges below are catalogue parts. These fittings are for equipment lines — pumps, machines, coolant, beverage and process water — not for household plumbing.
A typical request: brass throughout, because the line is water and everything else on the machine is brass — G3/8 into the pump, 1/4 NPT to the gauge, a barb for 12 mm hose. Two of those three can be bought.
The third is a machined brass fitting.
Brass fitting forms and size ranges
| Form | Ports | Size range | Standard finish | Notes |
|---|---|---|---|---|
| Hex nipple | M × M, same size | G1/8–G1; NPT 1/8–1 | plain, nickel | see male-to-male adapters for mixed pairs |
| Reducing nipple | M × M, two sizes | G1/4–G1 in one-step reductions | plain, nickel | — |
| Female coupling (socket) | F × F | G1/8–G1; NPT | plain, nickel | see female-to-female adapters |
| Reducing coupling | F × F, two sizes | G1/4–G1 | plain | — |
| Reducing bushing | M outside × F inside | G1/8–G1 in one-step reductions; NPT | plain, nickel | see female-to-male adapters and bushings |
| Street elbow 90° | M × F | G1/8–G1; NPT | plain, nickel | see threaded elbows |
| Female elbow 90° | F × F | G1/8–G1 | plain | — |
| Tee FFF and MFF | three ports | FFF G1/8–G1; MFF G1/4–G3/4 | plain, nickel | see threaded tees |
| Cross | four ports | G1/4–G3/4 | plain | — |
| Hose barb | M or F × barb | G1/8–G1 to 4–25 mm hose | plain, nickel | see hose barb adapters |
| Plug and cap | M plug; F cap | G1/8–G1; NPT | plain, nickel | hex head or socket |
| Hex extension nipple | M × F, long | G1/4–G3/4 in a few lengths | plain | machined in other lengths |
| Bulkhead union | F × F with jam nut | G1/8–G3/4 | plain, nickel | see bulkhead fittings |
| Compression and push-in fittings in brass | tube × thread | 4–16 mm tube | nickel | see compression and push-in fittings |
Need brass pipe fittings in a size, thread or material no catalogue lists? EKINSUN is a custom parts manufacturer: we make brass pipe fittings to your drawing, sketch or sample — brass CW614N, 304 or 316L stainless steel — from 1 piece, quoted in 12 hours and shipped duties paid. Already a catalogue size? Ask us too — we may have it in stock, and larger quantities cost less per piece. All custom adapters and fittings →
Which brass for which line
| Grade | Designation | How the fitting is made | Use it for | Watch |
|---|---|---|---|---|
| Forging brass | CW617N (CuZn40Pb2) | hot forged, then machined; the standard fitting alloy | air, oil, general water | dezincifies slowly in hard or chlorinated water |
| Free-cutting brass | CW614N (CuZn39Pb3) / C36000 | machined from bar; the custom fitting alloy | custom nipples, tees, elbows, barbs, adapters | as above; nickel plating helps |
| Dezincification-resistant brass | CW602N (CuZn36Pb2As) / DZR | machined from bar, or forged | hot water, hard water, chlorinated and marine water | specify it when the water is aggressive; costs more |
| Lead-free brass | CW511L, CW724R (silicon brass) | machined or forged | drinking-water contact where a lead limit applies | specified by the project; a certificate follows the alloy, not the fitting |
| Naval brass, bronze | CW712R; CuSn5Zn5Pb5 (gunmetal) | machined or cast | seawater | gunmetal for cast valve bodies |
| Nickel-plated brass | any of the above, plated | plated after machining | appearance, wear on tube fittings, corrosion | plating is not a substitute for DZR in aggressive water |
Brass fittings seal on BSP parallel threads with a washer or O-ring on the face and on tapered R and NPT threads with tape or sealant on the thread; the two are not mixed on one joint. Brass on brass gives the cleanest seal; brass into an aluminium 6061 housing needs a sealant and a check for galvanic corrosion in wet service, and brass into stainless is fine.
Identify the thread before you order the brass fitting. Measure the outside diameter of a male thread, or the inside diameter at the mouth of a female one, with a caliper, and count the threads in 25 mm or in one inch. A G1/4 male measures about 13.2 mm across and has 19 threads per inch; a 1/4 NPT male measures about 13.7 mm and has 18; an M14×1.5 measures 14.0 mm with 1.5 mm between crests. Those three are the ones most often confused on a fitting, and only the metric one is not tapered. Then check whether the thread is parallel or tapered by measuring the diameter at the first and the fifth turn. The fitting thread identification chart lists every common pipe, port and tube thread with its diameter, pitch and seal, and the BSPP vs BSPT note explains the parallel and taper forms of the same BSP size.
What to send for a brass fitting that is not catalogued
- Each port: male or female, standard (G, R, NPT, metric), size and pitch, or hose inside diameter for a barb.
- Form: nipple, coupling, bushing, elbow, tee, barb, plug; length, hex and bore if they matter.
- The water: cold, hot, hard, chlorinated, seawater, or air and oil; it picks the brass.
- Finish: plain or nickel plated.
- Quantity: from 1 piece.
Where the brass fitting catalogue stops
| What you need | In the catalogue? | What we make |
|---|---|---|
| Nipple, coupling, bushing, elbow, tee, barb, plug or cap in one standard, G1/8–G1 or NPT, forged brass | Yes | Buy it from stock, or have it made to order from 1 piece; no one-off competes on price with a forged brass fitting. Standard parts: ask us too — we may have them in stock. |
| Reducing nipple, bushing or coupling in a one-step reduction | Yes | Standard sizes: buy it off the shelf, or have it made to order from 1 piece. Standard parts: ask us too — we may have them in stock. |
| A brass fitting with a G end and an NPT end, or a metric port for a sensor, pump or valve | No | Machined from CW614N bar, each end to its own standard, from 1 piece. |
| A two-step reduction, a tee with three sizes, or an elbow with a gauge port | No | Machined. |
| An extension nipple, elbow or adapter of a length that clears a housing | No | Machined to length. |
| A hose barb for a hose size the catalogue skips, or a barb elbow or tee | No | Machined; barb profile to the hose. |
| A fitting in DZR brass CW602N, lead-free brass, bronze or gunmetal | No | Machined from the alloy named; certificate per batch on request. |
| A fitting for a drinking-water approval, or with a pressure or temperature rating on the machined part | Partly | The alloy certificate follows the bar; approvals and ratings are not claimed for a machined fitting, and we say so before quoting. |
Brass grades, and the materials beside brass
| Material | Designation | Where it fits here |
|---|---|---|
| Forging brass | CW617N | standard brass pipe fittings |
| Free-cutting brass | CW614N / C36000 | machined brass fittings |
| DZR brass | CW602N | aggressive water |
| Bronze and gunmetal | CuSn5Zn5Pb5 | seawater and cast valve bodies |
| Stainless 304 | 1.4301 / A2 | the fitting material when brass tarnish or zinc loss matters |
| Stainless 316L | 1.4404 / A4 | chemical and marine lines beside brass |
| Aluminium 6061 | AlMg1SiCu | the housing a brass fitting screws into; sealant and galvanic check in wet service |
| Aluminium 7075 | AlZn5.5MgCu | machined manifold blocks with brass fittings |
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
- fitting types chart — every fitting form by ports and standard
- brass fasteners — brass screws, nuts and standoffs
- Brass machining — turned brass parts of every kind
- Plumbing thread adapters — male-to-female and BSP-to-NPT adapters for pipework
- Hose barb adapters — barbs in brass and stainless
- pump fittings — brass connections on pumps
- threaded tees — brass tees in every port combination
- fitting thread identification chart — G, R, NPT and metric by diameter and pitch
Frequently asked questions
CW617N (CuZn40Pb2) is the forging brass that standard fittings are made from; CW614N (CuZn39Pb3, sold as C36000 in the US) is the free-cutting brass that custom fittings are machined from bar. For a fitting in service the two behave the same; the grade follows the process.
They tarnish but do not rust. In hard, hot or chlorinated water ordinary brass slowly loses zinc (dezincification) and weakens; dezincification-resistant brass CW602N is specified for those lines, and bronze or gunmetal for seawater.
No. G (BSPP) is parallel and 55 degrees, NPT is tapered and 60 degrees, and the diameters are close enough to start and jam. A G-to-NPT brass adapter with each end cut to its own standard is machined, from 1 piece.
Yes. Nipples, tees, elbows and barbs with a metric fine port, in CW614N or DZR brass, plain or nickel plated, are machined from bar, from 1 piece.
EKINSUN LTD is a custom parts manufacturer that machines brass nipples, couplings, bushings, elbows, tees, barbs and plugs in CW614N, CW602N DZR and bronze with G, R, NPT and metric threads, from 1 piece, with a quote within 12 hours.
No list price. Forged catalogue fittings cost cents; a machined fitting is priced by bar size, the threads, any milling, plating and quantity. A CW614N G × NPT nipple is a short lathe job; a DZR tee with three sizes and a gauge port is a milled and drilled part and priced as one. Where a forged catalogue fitting would do, the quote says so.
Send the ports and the water
Each port (thread or hose ID), form, length or hex if they matter, the medium (cold, hot, hard or salt water; air; oil), finish, quantity. A photo of the line 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.