A micro switch’s terminals set how it joins your circuit, and they fall into a few families: solder lugs (wires soldered to flat tabs), quick-connect tabs (push-on receptacles in standard widths), and PCB through-hole or SMT pins (mounted to a board). The choice is mechanical, not electrical, but it still gates a replacement. A quick-connect receptacle sized for 1/4 inch (6.35 mm) will not seat on a 3/16 inch (4.75 mm) tab, and a solder-lug part needs hand or wave soldering that a PCB layout may not accept. Read the terminal type and dimension on the part you are replacing first, because a switch that matches on rating and footprint can still be unwireable in your assembly.
Swiclick supplies G-series snap-action micro switches with PCB, solder, quick-connect, and 90° bend-foot terminals, so a terminal mismatch is usually solved by ordering the right variant rather than reworking the harness. The matching rule follows.
The terminal families
- Solder lug. Flat tabs that wires are soldered to before mounting. The most standard form, and the best for high current ratings, because a soldered joint dissipates heat well. The trade-off is a manual soldering step, so it suits prototypes and smaller runs more than high-volume lines.
- Quick-connect (faston) tabs. A male tab that a female push-on receptacle snaps onto, with no soldering or crimping at the switch. Fast to assemble and service, available in standard widths. The most-requested form for harness wiring.
- PCB through-hole and SMT pins. Pins that mount into a board, either through-hole (soldered on the rear) or surface-mount (set in solder paste and reflowed). SMT allows tighter pitch and miniaturization and is the common choice on modern boards.
Many basic-switch families encode the terminal in the part number, for example S for solder, E for quick-connect, J for PCB. The same switch body is often offered in several terminal types, which matters for the matching step below.
Quick-connect sizes are not interchangeable
Quick-connect tabs come in standard widths. A receptacle is sized to one of them and will not seat correctly on another, so the width is part of the spec, not a detail:
| Quick-connect tab width | Common name |
| 6.35 mm | 1/4” (0.250”) |
| 4.75 mm | 3/16” (0.187”) |
| 2.8 mm | — |
| 1.57 mm | — |
Mixing a 1/4” receptacle onto a 3/16” tab gives a loose joint that overheats under load. Confirm the tab width of the original before you treat two quick-connect parts as equivalent.
Matching terminals in a replacement
This is the exact issue in a DigiKey TechForum case: an engineer evaluating a replacement found it had solder terminals while the application used quick-connects, then discovered, deep in the datasheet, that the solder version of that switch also accepts 3/16” push-on quick-connects. Three steps avoid the trap:
- Read the original’s terminal type and dimension. Solder lug, quick-connect (and which width), through-hole, or SMT. Check the datasheet, not just the photo, because plating and exact form vary between near-identical parts.
- Match the type, or change the variant. Terminal type is usually a configurable option on a given switch body, so a mismatch often means ordering the right variant of the same part, not abandoning the cross-reference.
- Watch the cross-form cases. Some solder lugs accept push-on quick-connects of a matching width, and some quick-connect tabs can be soldered to. These are the exceptions that rescue a substitution, but verify them on the datasheet rather than assuming.
A terminal mismatch is one of the most solvable cross-reference blockers, which is why it is worth catching early: the fix is often a part-number change, not a board or harness redesign.
Which terminal for which job
For high-current loads, solder lugs and quick-connects carry and dissipate heat better than fine PCB pins, which is why basic switches in appliances and power circuits favor them. For dense, high-volume boards, through-hole and SMT pins win on assembly cost and miniaturization. For anything that gets serviced or re-harnessed in the field, quick-connects save the unsolder-and-resolder cycle that makes a soldered switch the “problem child” of a repairable assembly. Match the terminal to the way the product is built and maintained, not only to the schematic.
How Swiclick handles terminals
Swiclick builds snap-action micro switches in the G series (G10, G15, and G20) with terminals in PCB mount, solder, quick-connect, and 90° bend-foot, in SPST (NO/NC) and SPDT, certified to UL, ENEC (ENEC-01613), and TÜV Rheinland under an ISO 9001 quality system. Because the same switch body is offered across terminal types, a terminal difference between your current part and a Swiclick equivalent is usually closed by variant selection.
For a production design or a second source, confirming the terminal variant early is one of the cheapest blockers to clear. Send the terminal type and dimension of the part you are replacing with the part number, and an application engineer will confirm the matching G-series variant against the datasheet.
FAQ
No. They are different tab widths (6.35 mm and 4.75 mm). A receptacle made for one will not seat correctly on the other, giving a loose joint that overheats under load. Match the width.
Sometimes. Some solder lugs accept a push-on quick-connect of the matching width, and many switch bodies are offered in both terminal types. Confirm on the datasheet before treating them as equivalent.
Solder lugs, because a soldered joint dissipates heat well and carries higher current reliably. Quick-connects are next. Fine PCB pins are sized for lower-current board-level signals.
Through-hole pins pass into a board and are soldered on the rear; SMT pins sit on solder paste and are reflowed. SMT allows tighter pitch and miniaturization and is common on modern boards.
Often not. Terminal type is usually a configurable option on the same switch body, so a mismatch is frequently solved by ordering the right variant rather than reworking the board or harness.
