KSH451J 50 LFS Equivalent & Substitute Parts

Part Overview

The KSH451J 50 LFS is a tactile switch manufactured by C&K, classified as SPST-NO (Single Pole Single Throw - Normally Open) with a contact rating of 0.05A at 12VDC. This surface mount component features a square button actuator with 5.00mm height and is designed for off-momentary switch function applications. The product is currently obsolete, making identification of compatible substitute parts essential for ongoing design support and component procurement.

Substiute Parts

KSH451J 50 LFS

C&KIn Stock: 974KSH451J 50 LFS Datasheet

Current PartRFQ

KST241JLFS

C&KIn Stock: 8765KST241JLFS Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the KSH451J 50 LFS is determined by strict equivalence across the following critical parameters:

Circuit configuration must remain SPST-NO with off-momentary switch function. Contact current rating must support 0.05A minimum. Mounting type must be surface mount with J lead termination. Actuator height must be 5.00mm to maintain PCB clearance and mechanical compatibility. Switch travel distance must be 1.30mm. Operating force must be 350gf. Mechanical life must meet or exceed 100,000 cycles. Ingress protection must be IP40 or higher. Operating temperature range must encompass the -40°C to 90°C specification or be compatible with the application's actual operating window.

The KST241JLFS qualifies as a direct substitute based on these parameters, with the following considerations: it maintains identical circuit configuration, switch function, actuator height, switch travel, operating force, mechanical life, and ingress protection. The contact voltage rating increases from 12VDC to 32VDC, which is a non-limiting improvement for applications operating at or below 12VDC. The outline dimensions are marginally smaller (6.20mm x 6.20mm versus 6.30mm x 6.30mm), which does not affect PCB layout compatibility. The operating temperature range is slightly reduced to -40°C ~ 85°C, which remains suitable for most industrial applications.

Parameter Comparison

Engineering Selection Recommendations

The KST241JLFS is the qualified substitute for the obsolete KSH451J 50 LFS based on functional and mechanical equivalence. The substitute maintains all critical electrical and mechanical parameters required for direct replacement in SPST-NO tactile switch applications.

The KST241JLFS offers the advantage of active product status, ensuring long-term availability and supply chain continuity. The higher voltage rating (32VDC versus 12VDC) presents no limitation for applications designed for 12VDC operation and provides additional design margin. The marginally reduced outline dimensions (6.20mm x 6.20mm) are compatible with existing PCB layouts designed for the original part.

The operating temperature range reduction from -40°C ~ 90°C to -40°C ~ 85°C requires verification only if the application requires sustained operation above 85°C. For standard industrial temperature ranges, this difference is not a limiting factor. Both parts maintain identical RoHS compliance status and moisture sensitivity classification, ensuring regulatory and environmental compatibility.

Frequently Asked Questions (FAQ)

Q: Can the KST241JLFS be used as a direct replacement for the KSH451J 50 LFS without PCB modifications?

A: Yes. The KST241JLFS maintains identical actuator height (5.00mm), J lead termination, and outline dimensions within 0.10mm tolerance. No PCB layout changes are required.

Q: What is the significance of the voltage rating increase from 12VDC to 32VDC?

A: The higher voltage rating indicates the substitute can safely operate at higher voltages. For applications designed at 12VDC, the 32VDC rating provides additional design margin and does not affect compatibility.

Q: Does the 5°C reduction in maximum operating temperature affect compatibility?

A: The operating temperature range reduction from 90°C to 85°C requires evaluation only if your application requires sustained operation above 85°C. For standard industrial applications operating within -40°C to 85°C, this difference is not a limiting factor.

Q: Are there packaging differences between the original and substitute parts?

A: The KSH451J 50 LFS packaging is listed as standard, while the KST241JLFS is supplied in Tape & Reel (TR) format. Both are surface mount compatible. Verify tape and reel specifications with your procurement requirements.

Q: What compliance certifications apply to the substitute part?

A: The KST241JLFS is ROHS3 compliant, REACH unaffected, and classified as EAR99 for export control purposes. These certifications meet or exceed the original part's compliance status.

Q: Is the substitute part currently available?

A: Yes. The KST241JLFS is in active production status with 8661 pieces in stock, ensuring reliable supply chain availability compared to the obsolete original part.