ST21F2MA1B Toggle Switch DPDT Equivalent & Substitute Parts

Part Overview

The ST21F2MA1B is a panel mount toggle switch manufactured by APEM Inc., configured as a Double Pole Double Throw (DPDT) switch with On-On functionality. This component is rated for 0.4VA at 20V AC/DC operation with a flatted brass nickel-plated actuator. The part is currently obsolete, making equivalent substitutes necessary for ongoing maintenance, repair, and new design applications where compatible electrical and mechanical specifications are required.

Key Parameters

Parameter	ST21F2MA1B Value
Manufacturer	APEM Inc.
Circuit Configuration	DPDT
Switch Function	On-On
Current Rating	0.4VA (AC/DC)
Voltage Rating - AC	20 V
Voltage Rating - DC	20 V
Mounting Type	Panel Mount, Right Angle
Termination Style	PC Pin
Panel Cutout Dimensions	Circular - 6.35mm Dia
Bushing Thread	1/4-40
Operating Temperature Range	-30°C ~ 85°C
Electrical Life	100,000 Cycles
RoHS Status	ROHS3 Compliant
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitute parts for the ST21F2MA1B are grouped based on strict electrical and mechanical compatibility criteria. The primary substitution logic is based on the following allowed parameters:

Critical Matching Parameters:

Circuit Configuration: DPDT (mandatory match)
Switch Function: On-On (mandatory match)
Mounting Type: Panel Mount, Right Angle (mandatory match)
Termination Style: PC Pin (mandatory match)
Panel Cutout Dimensions: Circular - 6.35mm Dia (mandatory match)
Bushing Thread: 1/4-40 (mandatory match)
Operating Temperature Range: -30°C ~ 85°C (mandatory match)
Electrical Life: 100,000 Cycles (mandatory match)

Electrical Rating Compatibility: Substitutes are divided into two electrical categories based on current and voltage ratings:

Category A (Direct Electrical Match): 0.4VA at 20V AC/DC - identical to ST21F2MA1B
Category B (Higher Electrical Rating): 5A at 120V AC/28V DC - suitable for applications requiring higher power handling

Mechanical Variations Permitted:

Actuator Type: Flatted (original) or Locking Lever (substitutes)
Actuator Length: Minor variations (16.51mm to 18.59mm) within panel mount compatibility
Actuator Material: Brass with different plating (Nickel vs. Chrome)
Ingress Protection: Standard or IP67 rated variants
Features: Standard or Epoxy Sealed Terminals

All substitute parts are manufactured by C&K (7000 Series) and maintain active product status with current availability.

Parameter Comparison

Parameter	ST21F2MA1B	7201K12ABE	7201K12AGE	7201K12APE	7201K12AQE	7201K12CWABE	7201K12CWAQE	7201K12CWASE	7201K2A3QE	7201K2ABE	7201K2ABE3
Manufacturer	APEM Inc.	C&K	C&K	C&K	C&K	C&K	C&K	C&K	C&K	C&K	C&K
Circuit Configuration	DPDT	DPDT	DPDT	DPDT	DPDT	DPDT	DPDT	DPDT	DPDT	DPDT	DPDT
Switch Function	On-On	On-On	On-On	On-On	On-On	On-On	On-On	On-On	On-On	On-On	On-On
Current Rating	0.4VA	0.4VA	5A	0.4VA	5A	0.4VA	5A	5A	5A	0.4VA	0.4VA
Voltage Rating - AC	20 V	20 V	120 V	20 V	120 V	20 V	120 V	120 V	120 V	20 V	20 V
Voltage Rating - DC	20 V	20 V	28 V	20 V	28 V	20 V	28 V	28 V	28 V	20 V	20 V
Mounting Type	Panel Mount, Right Angle	Panel Mount, Right Angle	Panel Mount, Right Angle	Panel Mount, Right Angle	Panel Mount, Right Angle	Panel Mount, Right Angle	Panel Mount, Right Angle	Panel Mount, Right Angle	Panel Mount, Right Angle	Panel Mount, Right Angle	Panel Mount, Right Angle
Termination Style	PC Pin	PC Pin	PC Pin	PC Pin	PC Pin	PC Pin	PC Pin	PC Pin	PC Pin	PC Pin	PC Pin
Panel Cutout Dimensions	Circular - 6.35mm Dia	Circular - 6.35mm Dia	Circular - 6.35mm Dia	Circular - 6.35mm Dia	Circular - 6.35mm Dia	Circular - 6.35mm Dia	Circular - 6.35mm Dia	Circular - 6.35mm Dia	Circular - 6.35mm Dia	Circular - 6.35mm Dia	Circular - 6.35mm Dia
Bushing Thread	1/4-40	1/4-40	1/4-40	1/4-40	1/4-40	1/4-40	1/4-40	1/4-40	1/4-40	1/4-40	1/4-40
Operating Temperature Range	-30°C ~ 85°C	-30°C ~ 85°C	-30°C ~ 85°C	-30°C ~ 85°C	-30°C ~ 85°C	-30°C ~ 85°C	-30°C ~ 85°C	-30°C ~ 85°C	-30°C ~ 85°C	-30°C ~ 85°C	-30°C ~ 85°C
Electrical Life	100,000 Cycles	100,000 Cycles	100,000 Cycles	100,000 Cycles	100,000 Cycles	100,000 Cycles	100,000 Cycles	100,000 Cycles	100,000 Cycles	100,000 Cycles	100,000 Cycles
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	RoHS Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Product Status	Obsolete	Active	Active	Active	Active	Active	Active	Active	Active	Active	Active
Ingress Protection	-	-	-	-	-	IP67	IP67	IP67	-	-	-

Engineering Selection Recommendations

Direct Electrical Equivalents (0.4VA @ 20V AC/DC):

For applications requiring identical electrical specifications to the ST21F2MA1B, the following C&K 7000 Series parts provide direct substitution:

7201K12ABE - Active product status, ROHS3 compliant, standard ingress protection
7201K12APE - Active product status, RoHS compliant, standard ingress protection
7201K2ABE - Active product status, ROHS3 compliant, standard ingress protection
7201K2ABE3 - Active product status, ROHS3 compliant, red anodized finish option
7201K12CWABE - Active product status, ROHS3 compliant, IP67 ingress protection

Higher Electrical Rating Alternatives (5A @ 120V AC/28V DC):

For applications where higher power handling is required, the following parts provide enhanced electrical ratings while maintaining mechanical compatibility:

7201K12AGE - Active product status, ROHS3 compliant, standard ingress protection
7201K12AQE - Active product status, ROHS3 compliant, standard ingress protection
7201K12CWAQE - Active product status, ROHS3 compliant, IP67 ingress protection
7201K12CWASE - Active product status, ROHS3 compliant, IP67 ingress protection
7201K2A3QE - Active product status, ROHS3 compliant, standard ingress protection

All substitute parts maintain active product status, ensuring long-term availability and supply chain continuity. ROHS3 compliance is standard across all recommended substitutes, with the exception of 7201K12APE which carries RoHS compliance. IP67-rated variants (7201K12CWABE, 7201K12CWAQE, 7201K12CWASE) are available for applications requiring dust-tight and waterproof operation.

Frequently Asked Questions (FAQ)

Q: Can I use a higher-rated substitute (5A @ 120V) in place of the ST21F2MA1B (0.4VA @ 20V)?

A: Yes. Higher electrical ratings are backward compatible for lower-power applications. A 5A @ 120V switch can safely operate in a 0.4VA @ 20V circuit. The switch will not be stressed and will provide reliable operation. However, the application circuit must not exceed the original 0.4VA @ 20V specifications.

Q: What is the difference between standard and IP67-rated variants?

A: IP67-rated variants (7201K12CWABE, 7201K12CWAQE, 7201K12CWASE) provide dust-tight and waterproof ingress protection. Standard variants offer no specified ingress protection. Select IP67 variants only if the application environment requires protection against dust or moisture ingress.

Q: Are all substitute parts mechanically compatible with the ST21F2MA1B panel cutout?

A: Yes. All substitute parts share identical panel cutout dimensions (Circular - 6.35mm Dia) and bushing thread specifications (1/4-40), ensuring direct mechanical compatibility with existing panel installations.

Q: What is the difference between actuator types (Flatted vs. Locking Lever)?

A: The ST21F2MA1B features a flatted actuator, while all C&K substitutes feature a locking lever actuator. Both actuator types are mechanically compatible with the panel mount configuration. The locking lever provides tactile feedback and may offer improved ergonomics in manual operation scenarios.

Q: Are there packaging differences between substitute parts?

A: Yes. Most substitute parts are supplied in Tray packaging. Verify packaging requirements for your procurement process, as some variants may have different packaging specifications.

Q: Which substitute part should I select for new designs?

A: For new designs requiring 0.4VA @ 20V operation, select 7201K12ABE, 7201K2ABE, or 7201K12CWABE based on ingress protection requirements. All three are ROHS3 compliant with active product status. For applications requiring higher electrical ratings, select from the 5A @ 120V variants based on environmental protection needs.

Q: What is the REACH compliance status of substitute parts?

A: All C&K substitute parts carry REACH Affected status, indicating they are subject to REACH regulations. The original ST21F2MA1B carries REACH Unaffected status. Verify REACH compliance requirements for your specific application and regulatory jurisdiction.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message