EV Charging Connector Stamping: Terminals, HVIL Contacts and…

A charging connector is the only part of an EV that carries high current in the open air, gets plugged and unplugged by hand, and has to survive rain, salt, vibration, and ten years of parking-lot duty. When it fails, the failure is not a check-engine light. It is a charging session that will not start, a connector that overheats at the handle, or a warranty claim on a vehicle that left the factory two years earlier. For the stamper, this part family is unforgiving in a different way: the critical geometry lives inside the die, the plating window decides whether the contact lasts, and the volume is high enough that small tolerance drift becomes a field recall.

This guide covers the stamped parts inside EV charging connectors: power terminals, HVIL and signal contacts, shield cans, ground springs, and the support hardware around them. It maps each part to materials, tolerances, plating, and process decisions you can verify against a real stamping supplier, including the exact capability parameters ISTAMPING runs on its production floor. If you are specifying, buying, or redesigning charging connector hardware, this is the reference for the metal parts side of the program.

In this guide:

Part-by-part breakdown of the stamped hardware in AC and DC charging connectors
Material selection table for power contacts, signal contacts, and shields
Design rules for high-current contact geometry, spring beams, and plating windows
Tolerance, flatness, and edge-condition requirements you should put on the print
How high-volume progressive stamping produces these parts: presses, dies, and speeds
Plating strategy: selective gold 2-8 µm, silver, tin, and where zinc 5-12 µm belongs
Quality system requirements: IATF 16949:2016, ISO 14001:2015, CMM, and in-line vision
A DFM checklist you can send to any stamper with your drawing

The Charging Connector Part Family

Charging connectors come in several architectures, but the stamped hardware inside them follows a common pattern. AC charging (Mode 2 and Mode 3) connectors carry lower current and put most of the engineering into the latching, sealing, and strain-relief systems. DC fast-charging connectors, in the CCS, GB/T, CHAdeMO, and NACS families, carry the highest currents in the vehicle electrical system, which is why their power terminals dominate the metal content of the connector. Regardless of standard, the stamped parts fall into four groups.

Power terminals and contacts. These are the current-carrying members: round or blade-style pins, socket contacts, and the spring-loaded contact beams that grip the mating pin. In a DC connector, each current path is typically built from a machined or stamped-and-formed contact assembly, with stamped springs and retention hardware around a solid pin. The stamped parts in this group must hold contact force over thousands of mating cycles while carrying continuous current that heats the joint.

HVIL and signal contacts. High-voltage interlock loop (HVIL) contacts are small, low-current parts that signal whether the connector is fully mated, so the vehicle knows it is safe to energize. Signal and thermistor contacts carry milliamps of sensor current. These parts look trivial next to the power terminals, but they are where plating and spring-rate control matter most, because a marginal signal contact produces intermittent faults that are nearly impossible to reproduce on a test bench.

Shielding and EMC hardware. Charging connectors sit next to the most powerful electrical noise sources on the vehicle, so the connector housing typically carries stamped shield cans, ground springs, and finger contacts that tie the cable shield to the chassis ground. These parts are stamped from copper alloys or plated steel, and their function is purely mechanical and electromagnetic: low resistance to ground, high spring deflection, and enough surface area to keep the shield continuous at the mating face.

Support and retention hardware. Retention springs, locking clips, cable strain-relief clamps, and ground bus hardware round out the family. These are often zinc-plated steel stampings, which is where the zinc 5-12 µm plating range in our capability sheet applies, and they are usually the lowest-cost parts in the connector while still carrying the reliability load of the mechanical interface.

Material Selection for Charging Connector Parts

The material choice for each stamped part is driven by three properties: electrical conductivity for current-carrying parts, spring rate retention for contact and retention parts, and corrosion behavior under the connector's service environment. The four material families below cover nearly every charging connector stamping, and each is a material ISTAMPING runs regularly on its progressive lines.

Material	Where it is used	Why it is specified
C2600 cartridge brass	Power terminal blanks, retention clips, crimp barrels	Good conductivity, excellent formability, low cost at high volume; the workhorse of connector stamping
C5191 phosphor bronze	Signal contacts, HVIL contacts, spring beams, shield fingers	High fatigue strength and stable spring rate, the standard choice for spring-loaded contact members
C11000 / C10200 copper	High-current bus paths, weld tabs, power contact carriers	Near-100% IACS conductivity; oxygen-free C10200 where weld porosity must be eliminated
C17200 beryllium copper	High-reliability spring contacts and battery-grade terminals	Highest strength of the connector copper alloys; specified where the spring must never relax

Strip stock for these parts typically runs from 0.05 to 3.0 mm thick and up to 650 mm wide, which covers everything from a thin signal contact to the heavy laminated bus path in a DC charging assembly. The strip width matters more than most buyers expect: a wider coil means more cavities across the die width, which directly lowers the piece price on a multi-up progressive layout. When you negotiate with a stamper, ask for the part count per stroke at your strip width, not just the press speed.

Designing the High-Current Contact Path

The power contact is where the charging connector earns or loses its reputation. A DC fast-charging session moves enough current to melt the connector if the contact resistance rises, so every decision in this section is a thermal decision first and a mechanical decision second.

Contact force is the specification that matters. The stamped socket or spring beam must generate enough normal force against the mating pin to hold contact resistance low, and it must hold that force over the connector's rated cycle life, typically specified at 10,000 mating cycles in the charging connector standards. Force comes from the beam geometry: length, width, thickness, and the yield strength of the material. C5191 is the default because its spring rate is stable over decades, while a cheaper brass spring can relax after hundreds of cycles and quietly raise the resistance.

Keep the current path short and wide. Every bend and every reduced cross-section in the current path adds resistance and heat. The stamped design should carry the current through the shortest straight run of the thickest strip the geometry allows, with the bend radii generous enough to avoid stress concentrations where the part is also carrying current. If the design forces a narrow neck, move the neck into the mechanical function and keep the electrical path separate, which is why high-current sockets are often built as a stamped carrier around a machined pin.

Design the plating window, not just the plated area. The contact zone, the surface that actually touches the mating pin, is where precious-metal plating earns its cost. A selective gold finish of 2-8 µm on the contact zone only keeps the plating cost proportional to the function, and the plating mask on the strip determines where the gold lands. The DFM review should lock the plating window location, size, and thickness before the die is cut, because the window is a tooling feature, not a cosmetic note.

Plan for heat from the start. The connector housing cannot conduct away what the stamped part cannot dissipate. Specify the thermal budget early: the resistance of the joint, the plating, the interface force, and the mating pin material all contribute to the temperature rise at the contact. A supplier that stamps, plates, and inspects in one chain can show you plating thickness data on every lot; a supplier that only stamps cannot see the problem until it is a field failure.

HVIL, Signal, and Interlock Contacts

The small contacts in a charging connector are easy to under-specify and painful to debug. The HVIL loop is a safety circuit: it must make reliable contact when the connector is fully seated and break reliably when it is not, and it must never bounce or intermittently drop out while the vehicle is charging. Because the current is milliamps, designers sometimes assume the contact can be anything, which is exactly wrong: low current means no self-cleaning arc, so the contact depends entirely on plating and spring force.

Signal contacts share the same physics. The mating force budget of the connector is finite, and the power terminals consume most of it, so signal contacts are designed with low but precise forces, which puts them firmly in C5191 territory with a gold finish in the 2-8 µm range on the contact zone. Thermistor contacts, which carry the temperature-sensor signal that tells the vehicle when the connector is overheating, are the same design problem with one extra constraint: their contact resistance contributes to a measurement chain, so plating thickness and consistency matter at a level that visual inspection cannot catch.

For these parts, the manufacturing question to ask the stamper is about process control, not capability: is the plating window verified by X-ray fluorescence on a per-lot basis, and is the critical spring dimension tracked by SPC through the production run? A connector that fails its HVIL check at the assembly line stops the build; one that fails in the field stops a recall. The 0.05-3.0 mm thickness range covers these parts at the thin end, and the same progressive die discipline that holds ±0.005 mm registration on a power terminal applies to a signal contact that weighs a fraction of a gram.

Tolerances, Flatness, and Edge Condition

Charging connector stampings carry three quality dimensions that do not show up on a simple length-and-width drawing: flatness, burr condition, and plating-window registration. Each one is a stamping process property as much as a print dimension.

Flatness. A socket contact that arrives twisted will bind in the housing, a shield can that is bowed will lose its grounding fingers, and a flat bus path that is not flat will weld poorly. Flatness is controlled in the die by coining and by the strip tension through the press, and verified on a CMM or optical system on the first article and on a sampling basis through production. If your part mates against another component, put the flatness spec on the print in millimeters, not in marketing language.

Burr and edge condition. The blanked edge of a stamped terminal carries a burr on one side, and the burr direction and height are controlled by the die clearance and the strip grain direction. In a charging connector, a burr on a contact beam can scrape the mating pin's plating on every insertion, and a burr on a weld tab can cause weld spatter. Specify burr direction on the print and ask the stamper for burr-height control in the die, which is standard practice on automotive-grade progressive tooling.

Plating-window registration. The position of the plated zone relative to the contact geometry is a tolerance in its own right. Piloted dies that hold strip registration to ±0.005 mm are what make selective plating repeatable across a multi-up layout: if the strip wanders, the gold drifts off the contact zone. This is the tolerance that ties the die, the press, and the plating line into one process, which is why the strongest suppliers run all three under one roof.

Stamping the Parts at Volume

Charging connector hardware is a high-volume product, and the economics of the program are decided by the tooling layout and the press line, not by the material. A progressive die with multiple cavities across the strip produces a part per stroke per cavity, so the piece cost falls as the layout widens. ISTAMPING runs this part family on a high-speed department of Aida presses in the 25-80 ton range at up to 300 strokes per minute, backed by a new-energy stamping workshop with 45-110 ton presses for the heavier bus paths and support hardware, for 21 presses in total across 10,000 m² of floor.

The die itself is where the program lives or dies. A charging connector terminal die typically runs 16 to 28 stations: piloting, blanking, forming, coining, bending, and final cut-off, with in-die operations like lancing and tapping placed where the strip is strongest. ISTAMPING builds these dies in its own tool room, using wire EDM, CNC machining centers, tooling grinders, and precision die benches, and tries every die out on its own presses before the first production lot. The practical effect of in-house tooling is lead time: when tryout reveals a springback problem, the correction is made in days on the same floor that runs production, not in a foreign tool shop with a week of shipping between every iteration.

Run the numbers the way a stamper runs them. At 300 SPM with a 4-up layout, the theoretical output is 72,000 parts per hour per press, which is why the practical limits of a charging connector program are rarely press speed: they are die reliability, plating capacity, and inspection throughput. Ask for the planned utilization of the layout, the tooling cost at your strip width, and the piece-cost curve at three annual volumes. The curve tells you whether your program is a good fit for a high-speed line or whether the part belongs on a heavier press at lower speed.

Plating and Surface Finish

Plating is the reliability interface of a charging connector. The base metal provides strength and conductivity; the plating provides corrosion resistance, wear resistance, and stable contact resistance for the life of the vehicle. Getting the plating right is a three-way decision between function, thickness, and process chain.

Finish	Typical thickness	Where it is used
Selective gold	2-8 µm on the contact zone	Power and signal contact zones that must hold stable resistance over 10,000 mating cycles
Silver	Thin over nickel, contact-grade	High-current DC contacts where conductivity and cost matter and cycling is moderate
Tin	Standard connector tin, bright or matte	Crimp barrels, retention hardware, low-cycle contacts
Zinc	5-12 µm	Steel support hardware: clamps, clips, brackets that see the weather

The selective plating mask on the strip is a tooling feature. It defines where the gold lands, and it must align with the contact geometry within the same ±0.005 mm registration that the die holds. Gold in the 2-8 µm range is specified on the contact zone because it delivers stable contact resistance with a wear layer that survives the connector's rated cycle life; plating the entire part in gold is usually a waste of cost that adds nothing to function. Zinc in the 5-12 µm range belongs on the steel support parts, where it provides the corrosion barrier against the road-salt environment that the copper alloys do not need.

Verification is the part of the process most buyers overlook. Plating thickness should be verified by X-ray fluorescence on a per-lot basis, and the plating bath chemistry should be documented in the same quality system as the stamping. If your supplier farms the plating out, ask how the strip travels, who owns the registration between stamping and plating, and who answers for a lot that fails the thickness audit. In a one-chain supplier, the answer is one company.

Quality and Certification

Charging connector hardware is automotive safety-adjacent, and the quality system is not optional. ISTAMPING operates under IATF 16949:2016, the automotive quality management standard, and ISO 14001:2015 for environmental management, and the quality lab runs CMM and optical measurement systems plus in-line vision on the press lines. For a charging connector program, the PPAP submission is built from the production process: dimensional data from the CMM first article, plating thickness data from X-ray fluorescence, SPC charts on the critical dimensions, and capability data from the production press, not from a prototype line.

Three questions separate a serious supplier from a stamping shop that happens to have a press. First, is the quality system IATF 16949:2016 certified, and does the certification cover the plating and secondary operations in the same scope? Second, does the quality lab run CMM and in-line vision, and can the supplier show you process data from the line that will actually run your part? Third, does the PPAP documentation live in the same system as the production data, so an audit trail runs from the die design to the shipping lot? The answers determine whether your program qualifies on the first submission or spends the year in re-qualification.

DFM Checklist for Charging Connector Parts

Send this checklist with your drawing. Each item is a decision your stamper can act on, and each one has a right answer that you can verify.

Material and strip: Specify the alloy and temper, the thickness within 0.05 to 3.0 mm, and the strip width up to 650 mm. Confirm the part fits a multi-up layout at that width.
Contact force: Specify the minimum normal force at the contact zone and the number of mating cycles the connector must survive. Design the spring beam in C5191 or C17200 if the cycle requirement is demanding.
Plating window: Mark the contact zone on the drawing, specify selective gold at 2-8 µm, and require XRF verification per lot. Agree on the window tolerance with the die builder before tooling starts.
Flatness and burr: Put flatness in millimeters on the print, specify burr direction, and require in-die burr control on any edge that touches a mating surface.
Registration: Confirm the die is piloted to ±0.005 mm, because every tolerance above depends on strip registration staying put at speed.
Quality system: Require IATF 16949:2016 certification, CMM and in-line vision inspection, and SPC on the critical dimensions. Ask who owns the plating data.
Volume and layout: Ask for the cavities per stroke, the planned press speed, and the piece-cost curve at three volumes before you approve the tooling quote.

How to Start Your Charging Connector Program

The cheapest way to de-risk a charging connector program is to get the DFM review before the die is quoted. Send the drawing, the annual volume, the mating-cycle requirement, and the plating spec, and a serious stamper will come back with three things: a tooling price, a piece-cost curve at three volumes, and a list of print items that will cost you money as written. The review costs nothing and it almost always changes the print for the better, because the person who has built a hundred connector dies sees the springback, the window alignment, and the multi-up opportunity that a first-time specifier cannot.

ISTAMPING runs charging connector hardware on the same 21 presses and the same quality system that produces automotive terminals for Tier 1 customers: Aida high-speed presses to 300 SPM, in-house progressive tooling to ±0.005 mm, selective plating from 2-8 µm gold to 5-12 µm zinc, and IATF 16949:2016 and ISO 14001:2015 certification across 10,000 m² in Dongguan. Send your drawing through the quote request or contact page, and we will return the DFM review with the cost curves before you commit to tooling.

EV Charging Connector Stamping: Terminals, HVIL Contacts and Fast-Charge Hardware