Molex 0757571421 Rectangular Connector - Equivalent & Substitute Parts

Part Overview

The Molex 0757571421 is a vertical header connector with 4 positions and 4.6mm pitch, designed for through-hole mounting in automotive applications. This connector features a breakaway header design with unshrouded construction and push-pull fastening. The part is currently obsolete, making identification of compatible substitutes essential for ongoing design support and component sourcing.

Key Parameters

Parameter	Value
Manufacturer Part Number	0757571421
Manufacturer	Molex
Series	MX150 75757
Connector Type	Header, Breakaway
Number of Positions	4
Number of Rows	2
Pitch - Mating	0.138" (4.60mm)
Row Spacing - Mating	0.236" (6.00mm)
Mounting Type	Through Hole
Contact Type	Male Blade
Termination	Solder
Fastening Type	Push-Pull
Insulation Material	Liquid Crystal Polymer (LCP), Glass Filled
Material Flammability Rating	UL94 V-0
RoHS Status	ROHS3 Compliant
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution eligibility for the Molex 0757571421 is determined by strict equivalence across the following critical parameters:

Connector type (Header, Breakaway)
Number of positions (4) and row configuration (2 rows)
Pitch spacing (0.138" / 4.60mm mating pitch, 0.236" / 6.00mm row spacing)
Contact type (Male Blade)
Mounting method (Through Hole)
Termination type (Solder)
Fastening mechanism (Push-Pull)
Insulation material (Liquid Crystal Polymer, Glass Filled)
Flammability rating (UL94 V-0)
Compliance standards (ROHS3, REACH Unaffected)

The substitute part Molex 0757571121 maintains full equivalence across all these parameters, differing only in product status (Active vs. Obsolete) and contact finish thickness specifications, which do not affect functional compatibility.

Parameter Comparison

Parameter	0757571421 (Main Part)	0757571121 (Substitute)
Manufacturer	Molex	Molex
Series	MX150 75757	MX150 75757
Connector Type	Header, Breakaway	Header, Breakaway
Number of Positions	4	4
Number of Rows	2	2
Pitch - Mating	0.138" (4.60mm)	0.138" (4.60mm)
Row Spacing - Mating	0.236" (6.00mm)	0.236" (6.00mm)
Contact Type	Male Blade	Male Blade
Mounting Type	Through Hole	Through Hole
Termination	Solder	Solder
Fastening Type	Push-Pull	Push-Pull
Contact Length - Mating	0.441" (11.20mm)	0.441" (11.20mm)
Contact Length - Post	0.120" (3.05mm)	0.120" (3.05mm)
Overall Contact Length	0.738" (18.75mm)	0.738" (18.75mm)
Insulation Height	0.177" (4.50mm)	0.177" (4.50mm)
Contact Shape	Square	Square
Contact Finish - Mating	Tin	Tin
Contact Finish - Post	Tin	Tin
Contact Material	Cartridge Brass	Cartridge Brass
Insulation Material	Liquid Crystal Polymer (LCP), Glass Filled	Liquid Crystal Polymer (LCP), Glass Filled
Material Flammability Rating	UL94 V-0	UL94 V-0
Insulation Color	Black	Black
RoHS Status	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)	1 (Unlimited)
REACH Status	REACH Unaffected	REACH Unaffected
Product Status	Obsolete	Active
Contact Finish Thickness - Mating	59.0µin (1.50µm)	100.0µin (2.54µm)
Contact Finish Thickness - Post	59.0µin (1.50µm)	100.0µin (2.54µm)

Engineering Selection Recommendations

The Molex 0757571121 is the direct functional equivalent for the obsolete Molex 0757571421. Both connectors are manufactured within the same MX150 75757 series and maintain identical mechanical and electrical specifications across all critical parameters.

The 0757571121 is currently in active production status with significantly higher inventory availability (20,446 pieces versus 761 pieces for the obsolete part). Both parts maintain full ROHS3 compliance and REACH unaffected status, suitable for automotive applications requiring UL94 V-0 flammability certification.

The only technical difference is the contact finish thickness, where the 0757571121 provides increased tin plating (100.0µin / 2.54µm versus 59.0µin / 1.50µm). This enhanced finish thickness provides improved corrosion resistance and contact durability without affecting mechanical or electrical compatibility.

Frequently Asked Questions (FAQ)

Q: Can the Molex 0757571121 directly replace the 0757571421 in existing designs?

A: Yes. Both connectors share identical pitch spacing (4.60mm), row configuration (2 rows, 4 positions), contact geometry, mounting method (through-hole solder), and fastening mechanism (push-pull). Mechanical and electrical compatibility is complete.

Q: What is the significance of the contact finish thickness difference?

A: The 0757571121 features thicker tin plating (100.0µin versus 59.0µin). This provides enhanced protection against oxidation and wear during mating cycles, extending connector service life without altering functional performance.

Q: Are both parts suitable for automotive applications?

A: Yes. Both the 0757571421 and 0757571121 are specified for automotive applications and maintain UL94 V-0 flammability certification and ROHS3 compliance required for automotive component qualification.

Q: Why is the 0757571421 listed as obsolete?

A: The 0757571421 has been superseded by the 0757571121 within the Molex product line. The newer part maintains full functional equivalence while offering improved contact durability through enhanced finish thickness and is currently in active production.

Q: Does packaging differ between these parts?

A: The 0757571421 packaging is not specified in available documentation. The 0757571121 is supplied in tube packaging. Confirm packaging requirements with your procurement specifications.

Q: Are moisture sensitivity considerations the same for both parts?

A: Yes. Both connectors carry MSL 1 (Unlimited) rating, indicating no moisture sensitivity restrictions for storage or handling.

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