The closest C&K PTS645 alternative from Swiclick is the KAN0649-1301C0101-BJ42, a 6 × 6 mm surface-mount tactile switch that shares the PTS645’s SPST-NO momentary action, 12 VDC / 50 mA signal rating, and 0.25 mm travel. On a standard 6 × 6 gull-wing land pattern it is footprint-compatible with the surface-mount PTS645 (now a Littelfuse brand), so most existing PTS645 SMT layouts accept it without a board redesign once the terminal geometry is confirmed. The KAN0649-1301C0101-BJ42 is rated at 260 gf and 100,000 cycles. Because the Swiclick KAN tact family is built in 100 / 160 / 260 gf force grades and 100,000-to-1,000,000-cycle life grades, the part is matched to your specific PTS645 variant rather than sold as a blanket replacement. Swiclick manufactures the KAN series at roughly 170 million units a month and ships free 1-to-50-piece samples in four working days.
Why engineers cross-reference the C&K PTS645
Most PTS645 cross-references start as a supply problem, not a preference. The PTS645 is a single-source Littelfuse part, and distributor pages for it commonly read “no known equivalent,” which is exactly the position a buyer does not want on a switch that sits under a production line. When lead times stretch or a variant goes on allocation, the design engineer who specified a sole-source 3-cent switch is the one explaining the line-down to the program manager. A qualified second source is the hedge. The catch is that a bad cross-reference is worse than none, because it fails in the field with your name on the change order. That is the difference this page is built around: an honest match, graded, not a slogan. Anyone promising a blanket 100% drop-in is selling optimism, not switches.
A recent cross-reference shows how this runs in practice. A domestic medical-device maker building an ICU patient monitor ran its front panel on a US medical-grade 6×6 mm illuminated tactile switch. When that part was placed on end-of-life and the last-time-buy fell short of the monitor’s long service life, the team needed a high-reliability second source. Swiclick matched the footprint and pin layout, held the incumbent’s 300,000-cycle mechanical rating along with its LED wavelength and brightness, and shipped finished lit samples with SGS, RoHS, and material-safety reports within five days. The customer qualified it over six weeks of feel-retention and environmental testing with no PCB change, which avoided a second device re-certification, and it now ships at about 35,000 units a month at roughly 30% lower cost.
PTS645 vs Swiclick KAN0649-1301C0101-BJ42: side by side
The table sets both parts against each other using published datasheet values. Where the PTS645 spans a range, the range reflects its build-a-switch options across variants.
| Parameter | C&K PTS645 (by variant) | Swiclick KAN0649-1301C0101-BJ42 |
| Body size | 6.0 × 6.0 mm | 6.0 × 6.0 mm |
| Mounting | THT / gull-wing SMT / J-bend / side-actuated | Surface-mount (SMT), 4 terminals, gull-wing, reflow |
| Contact form | SPST-NO, momentary | SPST-NO, momentary (1 pole, 1 throw) |
| Signal rating | 50 mA @ 12 VDC (to 16 VDC on some variants) | 50 mA @ 12 VDC (min 10 µA @ 1 VDC) |
| Operating force | ~100 to 400 gf (variant-dependent; e.g. 160 gf, 260 gf, 3.92 N) | 260 ± 50 gf (100 / 160 / 260 gf across the KAN series) |
| Travel | ~0.25 mm | 0.25 ± 0.1 mm |
| Rated life | 100,000 to 1,000,000 cycles (variant-dependent) | 100,000 cycles (KAN series specifiable to 1,000,000) |
| Sealing | Standard, plus IP67 sealed side-actuated (PTS645V) | Standard (not sealed); IP67 available on Swiclick KAN6xxx |
| Operating temp | −40 °C to +85 °C (typical) | −30 °C to +80 °C (KAN family spans −40 °C to +85 °C) |
| Contact resistance | ≤100 mΩ (initial, typical) | ≤100 mΩ (initial) |
How close is the match?
On body size, contact form, signal rating, and travel, the KAN0649-1301C0101-BJ42 maps directly onto the surface-mount PTS645. Four points need stating plainly rather than buried. Force: this Swiclick part is a 260 gf build, so if your PTS645 uses a lighter or heavier detent, order the matching grade from the 100 / 160 / 260 gf range instead of assuming the feel is identical. Life: the PTS645 ships from 100,000 up to 1,000,000 cycles depending on variant, and this KAN0649 is a 100,000-cycle build, so for a high-life PTS645 confirm the equivalent 500,000 or 1,000,000-cycle KAN grade before you commit. Temperature: this part is specified −30 °C to +80 °C against the PTS645’s wider typical −40 °C to +85 °C, so cold or hot extremes need the correct grade checked. Mounting: this is a surface-mount, gull-wing part matched to the SMT PTS645; a through-hole or side-actuated PTS645 needs a different Swiclick footprint, and a sealed PTS645V routes to the KAN6xxx IP67 family.
That makes the KAN0649-1301C0101-BJ42 a footprint-compatible alternative, not a pin-to-pin or drop-in replacement. If you are still comparing package styles across a design, our guide to the types of tactile switches sets 6×6 SMT next to the other common footprints.
The spec that actually predicts field failure
For a 12 VDC / 50 mA signal switch, cycle count is the number buyers compare, but it is rarely the number that fails a design in the field. At this current there is no arc to burn contamination off the contacts, so nothing self-cleans the interface. What decides long-term reliability is contact-resistance stability: how far resistance drifts as the plating wears and the wipe geometry changes over tens of thousands of actuations. A switch rated for a million cycles with an unstable low-current interface can read intermittent on a sensing line long before it wears out mechanically. The KAN0649-1301C0101-BJ42 specifies initial contact resistance at 100 milliohms or less and uses a silver-plated contact; on the KAN platform, plating is a specifiable lever, because plating choice, not the headline cycle number, is what governs low-current stability. When you request samples, test the parameter your datasheet cannot show you: resistance drift on your own board, at your own current, after your own cycle profile.
What each stakeholder signs off
A switch change on a production board is a committee decision. This page is built to give each role its answer.
| Role | What they need to clear | Where this cross-reference answers it |
| Design engineer | Footprint, force grade, travel, contact stability, CAD | Side-by-side table, force-grade options, contact-resistance section, STEP files on request |
| Procurement / SQE | Second source, lead time, MOQ, allocation risk | Free 4-day samples, 7–15 day standard production, MOQ 500, urgent-order support |
| Finance / economic buyer | BOM cost, switching cost, requalification effort | Lower BOM cost; footprint match means no board respin if the grade lines up |
| Management | Decision risk, liability, supplier credibility | 30+ years of OEM switch manufacturing under ISO 9001, IATF 16949, ENEC, and UL |
| End user / line | Same feel, no assembly change | Force grade matched to the incumbent so the button behaves the same on the panel |
Independent alternative, not affiliated
Swiclick is an independent switch manufacturer. This cross-reference exists for engineering evaluation only. Swiclick is not affiliated with, endorsed by, or a distribution partner of C&K or Littelfuse, and the PTS645 name is used solely to identify the part being cross-referenced. Swiclick publishes its cross-references graded: where a part needs a board change it says so, and where a high-life competitor grade cannot be matched it says that too. That honesty is the point, and it is what a sourcing team can actually take into a meeting.
Frequently asked questions about the C&K PTS645 alternative
No. It is footprint-compatible with the surface-mount PTS645 on a standard 6×6 gull-wing land, but terminal geometry, force grade, and life grade should be confirmed against your exact variant. Swiclick calls it a form-fit-function match confirmed by engineering, not a blanket drop-in.
The KAN0649-1301C0101-BJ42, a 6×6 mm SMT tactile switch with SPST-NO action, 50 mA / 12 VDC rating, 0.25 mm travel, and a 260 gf, 100,000-cycle build.
Yes. The PTS645 family includes gull-wing SMT, J-bend, and through-hole options, plus a sealed side-actuated PTS645V. The KAN0649-1301C0101-BJ42 matches the SMT gull-wing versions; other mounting styles map to different Swiclick parts.
The KAN tact family is specifiable from 100,000 to 1,000,000 cycles. This particular part is a 100,000-cycle build, so a higher-life grade is quoted to match a long-life PTS645 variant.
The KAN0649 is not sealed. For an IP67 requirement equivalent to the PTS645V, Swiclick’s KAN6xxx sealed tactile switches are the cross-reference.
Send the PTS645 part number through the form, email, or WhatsApp. Samples are free for 1 to 50 pieces and ship in four working days; pricing follows from the inquiry.
Request a cross-reference, datasheet, and samples
Send your exact PTS645 part number and Swiclick engineering will confirm the form-fit-function match against the KAN0649-1301C0101-BJ42, flag any terminal, force, or life-grade difference, and arrange samples for qualification on your own line. There is no account or pricing gate. Start with the datasheet, then reach the team by inquiry form, email, or WhatsApp. For a related switch family, see our Omron tactile switch cross-reference.
