KST221J Equivalent & Substitute Parts

Part Overview

The KST221J 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 32VDC. This surface mount component features top actuation with a 5.00mm actuator height and is designed for applications requiring momentary switching functionality. The KST221J is currently listed as obsolete, making identification of compatible substitute parts essential for ongoing production and maintenance applications.

Substiute Parts

KST221J

C&KIn Stock: 881KST221J Datasheet

Current PartRFQ

KST221JLFS

C&KIn Stock: 5201KST221JLFS Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the KST221J is determined by strict equivalence across electrical and mechanical parameters. The following criteria establish direct substitutability:

• Circuit configuration must remain SPST-NO
• Contact rating must match 0.05A @ 32VDC
• Mounting type must be Surface Mount
• Actuator height must be 5.00mm (vertical)
• Outline dimensions must be 6.20mm x 6.20mm
• Operating temperature range must span -40°C to 85°C
• Operating force must be 200gf
• Switch travel must be 1.30mm
• Mechanical life must be 100,000 cycles
• Ingress protection must be IP40
• Termination style must be J Lead

The KST221JLFS meets all these parameters and is classified as an active product, making it a direct functional equivalent suitable for replacement applications.

Parameter Comparison

Engineering Selection Recommendations

The KST221JLFS is the direct equivalent substitute for the obsolete KST221J. Both components share identical electrical and mechanical specifications, ensuring functional interchangeability in circuit applications. The primary distinction between these parts is product status and regulatory compliance.

The KST221J is classified as obsolete and carries RoHS non-compliant status. The KST221JLFS is an active product with ROHS3 compliance, making it the appropriate selection for new designs and applications subject to RoHS regulations. The KST221JLFS is supplied in Tape & Reel packaging, which is standard for production environments, whereas the KST221J was available in bulk packaging.

For applications requiring the KST221J, transition to the KST221JLFS to ensure long-term component availability and regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can the KST221JLFS directly replace the KST221J in existing designs?

A: Yes. The KST221JLFS is electrically and mechanically equivalent to the KST221J. All functional parameters, including contact rating, actuator dimensions, operating force, and mechanical life, are identical. Direct substitution is possible without circuit modification.

Q: What is the difference between the KST221J and KST221JLFS?

A: The primary differences are product status and compliance. The KST221J is obsolete and RoHS non-compliant. The KST221JLFS is an active product with ROHS3 compliance. Packaging differs: KST221J is supplied in bulk, while KST221JLFS is supplied in Tape & Reel format.

Q: Why is the KST221J listed as obsolete?

A: The KST221J has been discontinued by the manufacturer. The KST221JLFS serves as its active replacement, offering the same electrical and mechanical performance with updated regulatory compliance.

Q: Are there packaging considerations when switching from KST221J to KST221JLFS?

A: Yes. The KST221JLFS is supplied in Tape & Reel packaging, which is standard for automated assembly processes. If your production environment requires bulk packaging, consult with your component supplier regarding alternative packaging options for the KST221JLFS.

Q: Does the KST221JLFS meet current regulatory requirements?

A: Yes. The KST221JLFS is ROHS3 compliant and REACH unaffected, meeting current regulatory standards for electronic components in most jurisdictions.

Q: What is the mechanical life expectancy of the KST221JLFS?

A: The KST221JLFS is rated for 100,000 mechanical cycles, identical to the KST221J. This specification applies to the actuator mechanism under normal operating conditions.