Connector, relay and circuit protection sourcing
Wire-to-board and board-to-board connectors, FPC and I/O connectors, terminal blocks, relays, switches and resettable fuses, by complete ordering code. A connector is bought as a set: header, housing and terminals. We check that every part of the set is quoted, and that pitch, plating, contact side and packing match.
- Full mating sets quoted: header, housing and crimp terminal
- Pitch, positions, plating and contact side read from the ordering code
- Relay coil and contact ratings checked against your load
O que fornecemos
Six groups cover most connector and electromechanical lines on a BOM. In each one, two parts with the same family name can fail to mate, carry a different current, or switch a different load.
Connector lines are also where BOMs are most often incomplete. A drawing shows the header on the board; the housing and terminals on the cable are bought by someone else, or forgotten. We ask for the whole set so the cable and the board arrive together.
Fio para placa
Headers, housings and crimp terminals. Typical lines: JST PH and XH, Molex Micro-Fit 3.0 and PicoBlade.
Board-to-board and FPC
Mezzanine, FPC and FFC connectors where pitch, stack height and contact side are fixed by the design. Typical lines: Hirose FH12 and DF series.
I/O connectors
USB-C, USB, RJ45, D-sub and circular connectors. Typical lines: GCT USB4105, Amphenol and TE I/O ranges.
Terminal blocks
PCB terminal blocks and pluggable connectors, defined by pitch, wire range and current. Typical lines: Phoenix Contact and Würth ranges.
Relays and switches
Signal and power relays, tactile and toggle switches. Typical lines: Omron G5Q, G6K and G5LE.
Circuit protection
Resettable PTC fuses, fuses, varistors and gas discharge tubes. Typical lines: Bourns MF-MSMF, Littelfuse ranges.
What a connector quote depends on
Send what you have. Complete ordering codes are fastest; a drawing or a photo of the mating part works too, and we come back with candidate codes.
- Every part of the set: header, housing and crimp terminal each have their own code
- Complete ordering code, including positions, plating, colour, contact side and packing
- Wire gauge for crimp terminals, because the terminal code changes with the wire range
- Quantity and target date, counted per part: one housing needs one terminal per position
- Alternative rule: original only, discuss first, or your approved list
- For relays: coil voltage, and the load voltage and current the contacts switch
The quote line states the source channel, packaging, date code, lead time and validity. Parts are supplied as packed by the manufacturer. Nothing is substituted without your written approval.
Representative parts and their key numbers
These are lines we see often. The numbers are the ones a replacement must match, taken from the manufacturers’ datasheets and catalogues.
PHR-4, SPH-002T-P0.5S, B4B-PH-K-S
JST PH housing, terminal, header
2.0 mm
2 A (AWG #24), 100 V
Three codes for one connection
XHP-4, SXH-001T-P0.6, B4B-XH-A
JST XH housing, terminal, header
2.5 mm
3 A (AWG #22), 250 V
Does not mate with PH
43025-0400
Molex Micro-Fit 3.0 receptacle
3.00 mm, dual row
Terminals rated 5.0 A max
4 circuits
43030-0001 / 43030-0007
Micro-Fit 3.0 female terminal
AWG 20–24, tin
5.0 A max
Same terminal: reel / bag
FH12-24S-0.5SH
Hirose FPC connector
0.5 mm, 24 contacts
Bottom contact
Standard type
FH12A-24S-0.5SH
Hirose FPC connector
0.5 mm, 24 contacts
Top contact
“A” changes the contact side
USB4105-GF-A
GCT USB-C receptacle
USB 2.0, SMT
5.00 A total on VBUS pins
USB 2.0 only
G5Q-1A4 DC5
Omron power relay, SPST-NO
5 V coil, 40 mA
10 A at 125 VAC; 3 A at 250 VAC
5 A at 30 VDC
MF-MSMF050-2
Bourns resettable PTC fuse
1812 SMD
Hold 0.50 A, trip 1.00 A
Check max voltage against the rail
Example parts, not a stock list. Confirm the current datasheet and the exact suffix before design or purchase. Need one of these? Send the part numbers of the whole set and we confirm the orderable codes and stock.
How to specify each group
Two connectors that look alike can differ by half a millimetre of pitch, by the side the contacts face, or by the plating on the terminal. Two relays with the same outline can switch very different loads.
Each tab lists what defines the part, the numbers to compare, the trap we see most often, and what to send so we can quote without guessing.
What defines the part. Series, pitch, positions, header orientation, plating, and the wire range of the terminal.
Numbers to check. Pitch, positions, top or side entry, terminal wire range, plating, packing.
Common trap. One connection is three ordering codes. For JST PH that is the housing PHR-4, the crimp terminal SPH-002T-P0.5S and the header B4B-PH-K-S. PH is 2.0 mm pitch and XH is 2.5 mm; they look alike in a photo and do not mate. JST rates PH at 2 A with AWG #24 wire and XH at 3 A with AWG #22.
Envie-nos: All three codes, the wire gauge, and a photo of the mating part if you have one.
What defines the part. Pitch, contact count, contact side, actuator type, stack height and mating part.
Numbers to check. Pitch, contact count, top or bottom contact, actuator style, the cable it mates with.
Common trap. Hirose FH12-24S-0.5SH is the standard bottom-contact type; FH12A-24S-0.5SH is the top-contact type, with the same pitch and contact count. Fit the wrong one and the cable must be flipped, which the cable length or routing often does not allow. Hirose rates FH12 for 20 insertion cycles, so FPC connectors are not made for repeated mating.
Envie-nos: Full ordering code, and which side of the FPC carries the conductors.
What defines the part. Interface standard, contact count, mounting style, current rating, shell and panel features.
Numbers to check. Which signals are present, current per contact, mounting type, mating cycles.
Common trap. A USB-C receptacle is not always a full USB-C port. GCT lists USB4105-GF-A as a receptacle for USB 2.0, rated 5.00 A in total across the VBUS pins. It does not carry USB 3 signals. A footprint designed for one receptacle style rarely fits another.
Envie-nos: Full ordering code, the USB data rate you need, and the mounting style.
What defines the part. Pitch, positions, wire range, current and voltage rating, clamp type, fixed or pluggable.
Numbers to check. Pitch, wire range, current per position, clamp type, approvals.
Common trap. Terminal blocks come in pitches close to each other, such as 5.0 mm and 5.08 mm. The difference grows across positions until the part no longer fits the footprint. Pluggable blocks are a plug and a header with separate codes, like any other connector set.
Envie-nos: Full ordering code, the pitch from the drawing, and the wire size.
What defines the part. Contact form, coil voltage, contact rating at your load voltage, contact material, sealing and approvals.
Numbers to check. Coil voltage in the suffix, contact rating at your voltage, AC or DC load, sealing, life.
Common trap. The contact rating depends on the load voltage. Omron rates G5Q-1A4 SPST-NO at 10 A at 125 VAC, 3 A at 250 VAC and 5 A at 30 VDC. A “10 A relay” switching 230 V mains is a 3 A relay. Coil voltage is the last part of the code (DC5, DC12, DC24), and “-EU” versions have different specifications.
Envie-nos: Full ordering code, the load voltage and current, and whether the load is resistive, inductive or a lamp.
What defines the part. Hold and trip current for PTCs, current rating and breaking capacity for fuses, voltage rating, package.
Numbers to check. Hold current, trip current, maximum voltage, time to trip, package.
Common trap. A resettable PTC has two currents. Bourns rates MF-MSMF050-2 to hold 0.50 A and trip at 1.00 A. Between the two, the part may or may not trip, so a load near 0.6 A is not protected the way the label suggests. Each PTC also has a maximum voltage, which must be above your rail.
Envie-nos: Full ordering code, the normal and fault current, and the rail voltage.
Six problems buyers find after the order
Each of these looks fine on a quote and shows up at assembly, at first power-up or in the field. We check for them before a line is quoted.
Headers arrived, cables cannot be built
Housing and crimp terminals were never ordered
Every code of the mating set
Housing does not fit the header
Similar series with a different pitch, such as PH and XH
Pitch and series on both halves
FPC cable inserts upside down
Top-contact instead of bottom-contact connector
Contact side in the code against the cable
Crimps pull out or fail the pull test
Terminal for a different wire range
Terminal code against the wire gauge
Relay contacts weld or burn
Contact rating read at the wrong voltage
Rating at your load voltage and load type
PTC trips in normal use, or never trips
Load current between hold and trip
Hold and trip current against the load
Worked example: one cable, three part numbers
A board has a 4-position JST PH header, B4B-PH-K-S. The cable needs one housing, PHR-4, and four crimp terminals, SPH-002T-P0.5S.
For 2,000 boards that is 2,000 headers, 2,000 housings and 8,000 terminals, plus spares for crimp setup. A BOM line that says “JST 4-pin, 2,000 pcs” covers only one of the three, and does not say whether the pitch is PH or XH.
Send the header code and the wire gauge and we quote the full set with the counts.
Worked example: can this relay switch the load?
G5Q-1A4 DC5 has a 5 V coil drawing 40 mA, which is more than most microcontroller pins can supply, so it needs a transistor driver and a flyback diode.
On the contact side, a 230 VAC heater of 2 kW draws 2,000 ÷ 230 = 8.7 A. The relay is rated 3 A at 250 VAC, so it cannot switch that load, even though it carries a “10 A” rating at 125 VAC. The design needs a relay rated for at least 8.7 A at 250 VAC, with margin for the load type.
Three requests we see, and how we handle them
Each started as a short message with a part number. What we check, and in which order, decides whether the buyer gets a usable part or a second problem.
"We need 5,000 of this header"
We ask what mates with it. Most of the time the housing and terminals are needed too, often by a cable supplier. We quote the full set, with terminal counts per position and the wire gauge stated.
"A compatible connector at half the price"
Clone housings and terminals can look identical and still have different retention or contact force. We quote the original series by default, and list a second source only with your approval and a sample check.
"The relay is out of stock, any 10 A will do"
We read the original rating at your load voltage first, then the coil voltage, contact form and outline. A "10 A" relay from another series can carry a lower rating at 250 VAC.
Where these parts go
A control cabinet and a handheld device use the same connector families, specified differently. These are the requirements that change by application.
Automação industrial
Terminal blocks, pluggable I/O, power relays and connectors rated for vibration.
Controle de motor e robótica
High-current wire-to-board sets, locking connectors and protection parts.
Energia e potência
Power connectors, terminal blocks and relays rated at the mains or DC bus voltage.
Edge AI & AIoT
Fine-pitch FPC and board-to-board connectors for camera and display modules.
Eletrônicos de consumo
USB-C receptacles, FPC connectors, tactile switches and PTC fuses on reels.
Áudio e voz inteligentes
Board-to-board and FPC connectors, USB-C and small signal relays.
Why buyers send connector lines to us
Mating set completed
Header, housing and terminal checked on every line, with counts per position.
Ratings read at your conditions
Relay contact ratings at your load voltage, PTC hold and trip, connector current per contact.
Distribution and independent stock compared
Factory lead time, distributor stock and qualified independent stock in China quoted side by side, channel named.
Lifecycle flagged
EOL and last-time-buy status shown per line, with date codes.
Original packing kept
Reels, bags and trays as packed by the manufacturer. The packing suffix is quoted as ordered.
Answer within 24 hours
A quote, or the specific questions that stop us quoting, within 24 hours of a complete enquiry.
Quality checks for connectors and relays
Connectors and relays are copied in outline, and clones can fit the same footprint. The difference is in contact force, plating and retention, which a photo does not show.
- Bag, reel and carton labels checked against the ordering code, including the packing suffix
- Pitch, positions and outline compared with the manufacturer's drawing
- Housing marking, terminal plating colour and relay markings checked against the series
- Mixed lots, reworked or used parts rejected
- Parts supplied as packed by the manufacturer
- Pull tests, contact resistance, X-ray or other tests by an independent laboratory when the risk calls for it, quoted before you order
Connector and relay manufacturers we source
Molex
Wire-to-board, board-to-board, FPC and I/O
TE Connectivity
Connectors, relays and circuit protection
Also JST, Hirose, Amphenol, Würth Elektronik, Phoenix Contact, GCT, Omron, Panasonic, Bourns and Littelfuse. Todos os fabricantes
Connector and relay questions
Can you quote one connector part number?
Yes. Send the complete ordering code, quantity and target date. We reply within 24 hours of a complete enquiry with a quote or the questions we need answered.
Do I need to order housings and terminals separately?
Yes. The header, housing and crimp terminal are separate parts with their own codes. Send all three, or send one and we identify the others.
Are JST PH and XH interchangeable?
No. PH is 2.0 mm pitch and XH is 2.5 mm pitch. They do not mate.
What does the A in FH12A mean?
Hirose uses it for the top-contact type. FH12 without the A is the standard bottom-contact type.
Why does the same terminal have two codes?
Packing is often in the code. Molex 43030-0001 and 43030-0007 are the same Micro-Fit terminal on a reel and in a bag.
Is a 10 A relay good for 10 A at 230 V?
Not always. Read the rating at your load voltage. Omron G5Q-1A4 is 10 A at 125 VAC and 3 A at 250 VAC.
Do you sell crimp tools?
We source connectors and electromechanical parts. Tooling is outside our scope; we can name the tool the manufacturer specifies for your terminal.
Can you quote a second-source connector?
Yes, as a separate line, with your approval. Mating with your existing cables or boards should be checked on samples first.
How do you check connectors from independent sources?
Visual inspection in-house against a documented checklist, including labels, marking, outline and packing. Pull tests, contact resistance or X-ray are done by an independent laboratory when the order needs it, quoted before you order.
Related: Passive components · Discrete & power · BOM sourcing & kitting · Alternativas