Through-Hole Assembly Services in the UK
Through-Hole Assembly for Connectors, Power Components and Legacy Designs
Through-hole technology is still the right call for a lot of electronic products — especially when components have to cope with mechanical loading, being plugged and unplugged over and over, vibration, heat or hefty electrical currents.
It’s also the only sensible option for legacy equipment and specialist parts that simply don’t come in a workable surface-mount package.
At PCB Company, we’re a UK-based manufacturer offering through-hole PCB assembly to businesses across the UK and Europe that need accurate, dependable builds with a bit of commercial give-and-take.
We handle prototypes, quick-turn jobs, low-volume runs and full production, and there’s no standard minimum order.
We can look after the whole journey — from bare PCB manufacture and component sourcing through to THT assembly, inspection, testing and engineering rework. Or, if you’d rather, you can supply your own boards, components or complete kits.
What Is Through-Hole PCB Assembly?
Meeting and Exceeding Industry Standards
Through-hole assembly — you’ll also hear it called THT or plated through-hole assembly — uses components whose leads pass right through drilled and plated holes in the board.
Those leads are then soldered on the far side, giving you both an electrical connection and a joint that’s mechanically anchored in place.
Surface mount is brilliant for compact, high-density electronics, but it doesn’t push through-hole out of the picture for every job. Connectors, switches, transformers, relays, big capacitors, power devices and anything that takes a mechanical beating are often far happier in a through-hole format.
THT tends to get picked for:
- Industrial control and automation equipment
- Power conversion and distribution products
- Automotive and transport electronics
- Aerospace and defence systems
- Telecommunications infrastructure
- Medical and laboratory equipment
- Test and measurement instrumentation
- Legacy products and long-life equipment
- Boards with large connectors or user-operated controls
The assembly method should follow what the product actually needs — electrically, mechanically, environmentally and over its lifetime — rather than whatever packaging style happens to be in fashion.
When to Use Through-Hole Assembly
Through-hole technology remains appropriate when component leads need strong mechanical retention, when connectors are repeatedly mated and unmated, when power components carry higher current, or when a specialist or legacy component is not available in a suitable surface-mount package. THT can be used on its own or alongside SMT in a mixed-technology assembly.
When preparing a THT build, identify component lead forming, insertion constraints, soldering method, board thickness, hole and pad geometry, thermal sensitivity and any inspection or functional-test requirements.
THT Assembly for Legacy and Long-Life Products
Through-hole really comes into its own with mature products. Industrial, medical, transport and communications kit can stay in service for decades — long after the original components have become tricky to get hold of. A flexible assembly partner can help you:
- Keep established equipment in production
- Build up spare or service stock
- Bring in approved alternative components
- Roll out engineering modifications
- Recreate discontinued assemblies
- Back equipment refurbishment programmes
PCB Company can support existing designs through PCB manufacture, PCB assembly, component sourcing, testing and rework. And if a board revision’s on the cards, an engineering review helps make sure the proposed changes still play nicely with the rest of the assembly.
Flexible THT Assembly for B2B Requirements
Some OEMs want one supplier to run the entire build. Others already hold stock, have nominated components or work with approved suppliers they’d rather keep in their own hands. Both are fine by us.
Here are the routes we offer.
Full Turnkey Through-Hole Assembly:
Hand us your manufacturing data and bill of materials, and we’ll coordinate the lot — PCB fabrication, component sourcing, assembly, inspection and testing.
It saves you juggling a string of suppliers and gives you a clean path from data release to finished boards.
Partial Turnkey Assembly:
You supply the bits you want to keep control of — selected parts, programmed devices, customer-specific items — and we source the rest and put it all together.
This one works nicely when you’re already sitting on strategic stock or need to hang on to certain devices yourself.
Consigned Through-Hole Assembly:
You provide the PCB and the component kit; we do the assembly and whatever inspection or testing we’ve agreed.
Ideal when the stock’s already on the shelf, the materials are yours, or specific approved components have to be used.
Prototype and Quick-Turn THT Builds:
Small quantities usually need more flexibility, not less.
We take on prototype and low-volume through-hole work with no standard minimum order, so your engineers can check mechanical fit, electrical function and manufacturability before committing to a bigger production batch.
Our Through-Hole Assembly Process
Reliable THT work comes down to disciplined prep and steady, consistent workmanship. Component polarity, body height, lead forming, seating, orientation, solder coverage and board cleanliness all leave their fingerprints on the finished job.
Data and BOM Review
We go through the Gerber files, drill data, bill of materials, assembly drawings and any instructions you’ve sent. Where it helps, our engineers can offer Design for Manufacturability, Design for Assembly and Design for Test input before anything gets built.
This is the stage where we tend to catch things like:
- Unclear component polarity
- Reference designators that don’t line up
- Hole-to-lead relationships that won’t play nicely
- Component bodies fouling one another
- Solder joints you can’t actually get to
- Not enough test-point access
- Missing assembly instructions
- Connectors that don’t quite line up
Spotting these before a single component goes in saves you the delays, rework and wasted material that come from finding them later.
Material Verification and Kitting
Components get checked against the approved BOM and organised ready for the build. On turnkey projects, we handle the sourcing as part of the deal. For consigned kits, clear labelling, correct quantities and proper component identification keep everything moving.
Component Preparation and Placement
Through-hole leads often need forming, trimming or a bit of controlled prep to suit the footprint and the assembly drawing.
Then each part goes in — right position, right orientation, seated correctly. Connectors, switches and the bigger devices get extra care, since they usually have to line up precisely with an enclosure, front panel, cable assembly or mating hardware.
Soldering and Process Control
We pick the soldering route to suit the board design, the mix of components, the quantity and your spec. The aim is consistent wetting and sound joints, while keeping heat under control so neither the PCB nor the component bodies take any damage.
We can work to RoHS-compliant or specified non-RoHS requirements. Solder alloy, PCB surface finish, component termination and how everything behaves under heat all get factored in.
Inspection, Testing and Rework
Finished assemblies can go through visual and automated inspection, plus whatever electrical testing suits the project. What we can offer:
- Automated optical inspection
- In-circuit testing
- Flying probe testing
- Board-level functional testing
- System-level functional testing
- Engineering rework
If something’s not right, we can build approved corrective action or an engineering modification straight into the service.
Design Considerations for Reliable THT Boards
A board can be electrically spot-on and still carry needless manufacturing risk. Through-hole design points worth keeping an eye on:
- Finished hole size against the component lead diameter
- Annular ring and pad dimensions
- Clear polarity and orientation markings
- Room to insert, solder and inspect
- Support for heavy or mechanically loaded components
- Component seating and body-height requirements
- Lead length and protrusion specs
- Creepage and clearance on higher-voltage circuits
- Thermal relief and copper balance around joints
- Whether the PCB surface finish gets on with your solder process
- Connectors lining up with the final enclosure
Our engineers can look over your manufacturing data before production and flag anything likely to cause grief.
Sorting these out at the data stage is nearly always cheaper and quicker than fixing them once bare boards and components are already bought and committed.
Working with a UK THT Partner — and Serving Europe Too
A fair few of our customers land with us after wrestling with drawn-out lead times or hard-to-reach suppliers overseas. Keeping the work here in the UK tightens that loop — you’re dealing with the engineers actually doing the build, in your time zone and in plain English.
Being UK-based pays off on the practical side as well:
- Quicker turnaround and shorter shipping for customers across England, Scotland, Wales and Northern Ireland
- Straightforward logistics into Europe, with hands-on experience handling cross-border paperwork post-Brexit
- A firm grip on UK and EU compliance, including RoHS and REACH, plus specified non-RoHS work where your application needs it
- Traceability and support solid enough for regulated sectors like aerospace, medical, defence and industrial control
Whether you’re a start-up down in Cambridge, a long-established manufacturer in the Midlands or a design house over on the Continent, you get the same joined-up service — bare board right through to a tested, inspected assembly.
Why Choose PCB Company?
Our through-hole customers get:
- PCB fabrication and assembly under one UK roof
- Support from prototype all the way to production
- No standard minimum order quantity
- Full turnkey PCB, partial turnkey and consigned options
- RoHS-compliant and specified non-RoHS assembly
- DFM, DFA and DFT engineering support
- Inspection and electrical testing options
- Board-level and system-level functional testing
- Rework support for modifications and corrective actions
- UK-based communication for projects across the UK and Europe
What to Send for a BGA Assembly or Rework Quote
For accurate pricing and a realistic lead time, send us:
- Gerber files and drill data
- Bill of materials with manufacturer part numbers
- Assembly drawings
- Component polarity information
- PCB quantity and expected batch schedule
- Required solder alloy or compliance standard
- Details of any components you’re supplying
- Inspection and test requirements
- Programming requirements, if there are any
- Target delivery date
- Packaging or traceability instructions
We’ll go through it all and flag anything worth sorting out before manufacture starts.
Through-Hole Assembly FAQs
Absolutely. It’s still the go-to for connectors, power components, transformers, relays, switches and anything under mechanical stress. Plenty of modern boards mix through-hole components with surface-mount devices.
Yes. We can review existing manufacturing data, customer-supplied boards, component kits and approved engineering changes for legacy or repeat builds.
Yes. With no standard minimum order quantity, one-off prototypes and small batches sit happily alongside production work.
Yes. Full turnkey and partial turnkey options are both on the table. Or you can supply all the boards and components yourself for consigned assembly.
Yes to both. We’re based in the UK with UK project communication, and we supply customers right across Europe, handling the shipping and paperwork that goes with it.
We can — AOI, in-circuit testing, flying probe testing and functional testing are all available, depending on the test data you have and the verification strategy we agree.
Request a Through-Hole Assembly Quote!
Send PCB Company your BOM, Gerber files, assembly drawings, quantity and delivery requirement, and we’ll come back with a technical review and quote. Work with a UK through-hole specialist that serves customers throughout Europe too.