A contact has two jobs at once: carry current with low resistance, and press against its mate with a force that does not relax over years and thousands of cycles. The alloy answers the second job and the plating the first. Stamped-and-formed terminals come off a progressive die on a reel; turned pins come off a lathe one at a time. Which one your connector needs depends on the shape, the quantity and the current.
EKINSUN LTD is a custom parts manufacturer that makes terminals and contact pins to drawing: stamped-and-formed receptacles, tabs, crimp and PCB terminals in brass, phosphor bronze and beryllium copper on progressive dies, turned round pins and sockets in brass and phosphor bronze, tin, nickel, gold or silver plated, on reel or loose. The type table below lists the forms; the alloy and plating tables explain the two choices that decide a contact; the negative-space table marks what is stamped, what is turned and what is bought.
"A radar sensor pin, 0.8 mm, gold over nickel, 40,000 pieces a month. The turned quote is fine for a thousand and hopeless for forty thousand."
Quantity decides stamped against turned; the current decides the alloy; the mating cycles decide the plating.
| Type | Process | Materials | Plating | Where it goes |
|---|---|---|---|---|
| Receptacle (female) terminal | stamped and formed, on reel | phosphor bronze, brass, beryllium copper | tin; gold over nickel for signal | wire-to-board and wire-to-wire connectors |
| Tab (male) terminal, 2.8 / 4.8 / 6.3 mm | stamped, on reel or loose | brass, copper | tin, nickel | automotive and appliance connectors |
| Crimp terminal, ring, spade, fork, pin | stamped and formed | copper, brass | tin | wiring, distribution boxes |
| PCB pin and press-fit terminal | stamped, or turned for round pins | brass, phosphor bronze | tin; gold for press-fit signal | printed circuit boards |
| Signal terminal / contact spring | stamped and formed | phosphor bronze, beryllium copper | gold over nickel | sensors, switches, sliding contacts |
| Contact tip / rivet contact | stamped or headed | silver alloy on copper, copper | silver | relays, switches |
| Solder tag / earth tag | stamped | brass, copper | tin, silver | chassis earths, transformers |
| Turned contact pin, round | turned on a sliding-head lathe from 0.5 mm | brass CW614N, phosphor bronze | gold over nickel, tin, nickel | circular connectors, probes, radar sensors |
| Turned socket contact | turned and slotted | phosphor bronze, beryllium copper | gold over nickel | circular connectors |
| Busbar and battery tab | stamped, thick | copper, nickel-plated steel | tin, nickel | battery packs, power distribution |
| Alloy | Designation | Conductivity | Spring and relaxation | Use it for |
|---|---|---|---|---|
| Copper | Cu-ETP / C11000 | highest | none; deforms and stays | crimp terminals, tags, busbars — parts that do not spring |
| Brass | CuZn37 / C26800; CuZn30 / C26000 | medium | modest spring; relaxes when hot | tabs, pins, low-cycle terminals; the cost choice |
| Phosphor bronze | CuSn6 / C51900; CuSn8 | lower than brass | good spring, holds force over cycles and moderate heat | receptacles, contact springs, sockets |
| Beryllium copper | CuBe2 / C17200 | medium after ageing | the best spring and relaxation resistance | high-cycle and high-temperature contacts |
| Nickel silver | CuNi18Zn20 | low | good spring, corrosion resistant | connector shells, springs |
| Free-machining brass | CW614N / C36000 | medium | for turned parts only | turned pins and sockets |
| Plating | Over | What it does | Use it for |
|---|---|---|---|
| Tin | copper alloy, sometimes nickel underplate | solderable, low cost; fretting on vibrating low-force contacts | power terminals, crimp terminals, PCB pins |
| Nickel | copper alloy | hard barrier layer; wear resistant; a base for gold | tabs, pins in dry circuits, underplate |
| Gold over nickel | nickel underplate | no oxide, lowest and most stable contact resistance; flash for cost, thicker for cycles | signal contacts, sensors, high-cycle connectors |
| Silver | copper alloy | highest conductivity; tarnishes but the tarnish conducts | power contacts, relay tips, solder tags |
| Selective plating | — | gold only on the contact area, tin on the solder tail | volume terminals where gold cost matters |
| What you need | In the catalogue? | What we make |
|---|---|---|
| A standard crimp terminal, tab or PCB pin in a catalogue series | Yes | Buy it from stock; connector makers sell them by the reel and no custom part competes. |
| A receptacle, tab, crimp or PCB terminal of your own shape, thousands upward | No | Stamped and formed on a progressive die, plated, on reel; die quoted separately. |
| A round pin or socket, from a few pieces to tens of thousands | No | Turned from brass or phosphor bronze on a sliding-head lathe, plated, loose or in tape. |
| A round pin in very high volume | No | Stamped and rolled instead of turned once the quantity justifies the die, and we say at what quantity. |
| A contact in beryllium copper, nickel silver or a silver-alloy tip | No | Stamped or turned in the alloy named; heat-treated where beryllium copper needs it. |
| A terminal that must be moulded into a plastic housing | No | Stamped with retention features and supplied for insert moulding — see custom plastic parts. |
| A thick-stamped insert bushing for a connector housing | No | See custom stamped parts. |
| A contact pin in aluminium 6061, 7075 or stainless 304 | Partly | Aluminium and stainless pins are turned for structural or grounding roles; they are not contact materials for signal circuits, and we say so. |
| Material | Designation | Where it fits here |
|---|---|---|
| Copper | Cu-ETP / C11000 | crimp terminals, tags, busbar tabs |
| Brass | CuZn37, CuZn30 | stamped tabs and pins |
| Free-machining brass | CW614N / C36000 | turned pins and sockets |
| Phosphor bronze | CuSn6 / CuSn8 | receptacles, contact springs, turned sockets |
| Beryllium copper | CuBe2 / C17200 | high-cycle contacts |
| Nickel silver | CuNi18Zn20 | shells and springs |
| Nickel-plated steel | pre-plated strip | battery tabs and covers |
| Stainless 304 | 1.4301 | turned grounding pins and structural contacts, not signal contacts |
| Stainless 316L | 1.4404 | as above, for corrosion duty |
| Aluminium 6061 | AlMg1SiCu | turned structural pins; not a contact material |
| Aluminium 7075 | AlZn5.5MgCu | as above |
Turned pins are round, precise and economical from a few pieces to tens of thousands; stamped-and-formed pins need a progressive die but cost a fraction each in volume and come on reels for automatic insertion. Round pins in small and medium quantities are turned; flat or formed contacts, and round pins in very high volume, are stamped.
Phosphor bronze (CuSn6 / CuSn8) for most receptacles and springs: good spring, holds its force over cycles and moderate heat. Beryllium copper where the contact sees very many cycles or high temperature. Brass for tabs and pins that do not spring; copper for crimp terminals that only conduct.
Gold does not oxidise, so the contact resistance stays low and stable over years and mating cycles; it is plated over a nickel barrier. Tin is the low-cost plating for power terminals and solder tails, and silver for the highest conductivity where tarnish can be tolerated.
Yes. Stamped-and-formed terminals are supplied on reel with the carrier strip to your insertion machine's pitch; turned pins are supplied loose or in tape.
EKINSUN LTD is a custom parts manufacturer that makes stamped-and-formed terminals and turned contact pins and sockets to drawing in brass, phosphor bronze, beryllium copper, copper and nickel silver, tin, nickel, gold or silver plated, on reel or loose, with a quote within 12 hours.
No list price. For stamped terminals the die is quoted separately and the part price follows alloy, thickness, plating and volume; for turned pins the price is per piece and follows the alloy, the features and the plating. The quote shows both routes where both apply.
Drawing or sample of the terminal and its mating part, current and cycles, wire size or PCB pitch, plating, quantity per year, reel or loose. From 1 piece turned, quote within 12 hours.
Terminals and contact pins stamped or turned in the right alloy and plating — from 1 piece turned, quote in 12 hours.