M50-4903345 Equivalent & Substitute Parts

Part Overview

The M50-4903345 is a rectangular connector header manufactured by Harwin Inc., designed for surface mount applications with 66 positions at 1.27mm pitch. This shrouded, board-to-board connector features male pins with gold-plated contacts and is rated for 1A per contact across an operating temperature range of -40°C to 105°C. The product is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and procurement.

Key Parameters

Parameter	Value
Connector Type	Header
Contact Type	Male Pin
Number of Positions	66
Number of Rows	2
Pitch - Mating	0.050" (1.27mm)
Row Spacing - Mating	0.050" (1.27mm)
Mounting Type	Surface Mount
Style	Board to Board
Shrouding	Shrouded - 4 Wall
Termination	Solder
Fastening Type	Push-Pull
Current Rating	1A per Contact
Operating Temperature	-40°C ~ 105°C
Contact Finish - Mating	Gold
Contact Finish - Post	Gold
Insulation Material	Liquid Crystal Polymer (LCP)
Material Flammability Rating	UL94 V-0
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution of the M50-4903345 is determined by strict equivalence across the following critical parameters:

Connector configuration: 66 positions, 2 rows, 0.050" (1.27mm) pitch with matching row spacing
Electrical characteristics: 1A per contact current rating, gold-plated mating and post contacts
Mechanical form factor: Surface mount, board-to-board, shrouded 4-wall design with push-pull fastening
Termination method: Solder termination
Environmental compliance: UL94 V-0 flammability rating, ROHS3 compliance, MSL 1 rating
Operating range: -40°C to 105°C

The substitute part SBH31-NBPB-D33-SM-BK from Sullins Connector Solutions meets all these criteria, with minor variations in insulation material composition and contact material that do not affect functional equivalence within the specified electrical and mechanical parameters.

Parameter Comparison

Parameter	M50-4903345 (Harwin)	SBH31-NBPB-D33-SM-BK (Sullins)
Connector Type	Header	Header
Contact Type	Male Pin	Male Pin
Number of Positions	66	66
Number of Rows	2	2
Pitch - Mating	0.050" (1.27mm)	0.050" (1.27mm)
Row Spacing - Mating	0.050" (1.27mm)	0.050" (1.27mm)
Mounting Type	Surface Mount	Surface Mount
Style	Board to Board	Board to Board
Shrouding	Shrouded - 4 Wall	Shrouded - 4 Wall
Termination	Solder	Solder
Fastening Type	Push-Pull	Push-Pull
Current Rating	1A per Contact	1A
Operating Temperature	-40°C ~ 105°C	-40°C ~ 105°C
Contact Finish - Mating	Gold	Gold
Contact Finish - Post	Gold	Gold
Material Flammability Rating	UL94 V-0	UL94 V-0
RoHS Status	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level	1 (Unlimited)	1 (Unlimited)
Insulation Height	0.224" (5.69mm)	0.213" (5.40mm)
Insulation Material	Liquid Crystal Polymer (LCP)	Polyamide (PA9T), Nylon 9T
Contact Material	Copper Alloy	Brass
Product Status	Obsolete	Active

Engineering Selection Recommendations

The SBH31-NBPB-D33-SM-BK is a direct functional equivalent for the obsolete M50-4903345. Both connectors satisfy identical electrical and mechanical requirements across all critical parameters: 66-position, 2-row configuration at 1.27mm pitch, 1A per contact rating, surface mount solder termination, and push-pull fastening. Both maintain UL94 V-0 flammability compliance, ROHS3 certification, and MSL 1 moisture sensitivity rating across the -40°C to 105°C operating range.

The substitute part is currently in active production status with confirmed inventory availability, eliminating supply chain risk associated with the obsolete original part. Minor material variations—insulation composition (LCP versus PA9T nylon) and contact material (copper alloy versus brass)—do not affect functional compatibility within the specified electrical and mechanical parameters. The 0.29mm difference in insulation height (5.69mm versus 5.40mm) falls within acceptable mechanical tolerance for board-to-board connector applications.

Frequently Asked Questions (FAQ)

Q: Can the SBH31-NBPB-D33-SM-BK be used as a direct replacement for the M50-4903345 without PCB redesign?

A: Yes. Both connectors share identical pitch (1.27mm), position count (66), row configuration (2), and mounting footprint specifications for surface mount solder termination. The 0.29mm difference in insulation height does not require PCB layout modification.

Q: What is the significance of the insulation material difference between LCP and PA9T nylon?

A: Both materials meet UL94 V-0 flammability requirements and are suitable for the specified operating temperature range. The material substitution does not affect electrical performance, contact retention, or mechanical durability within the stated application parameters.

Q: Are the gold contact finishes equivalent between the two parts?

A: Both parts feature gold-plated mating and post contacts. The Sullins part specifies flash thickness for contact finish, while the Harwin part does not provide thickness specification. Both meet the electrical and mechanical requirements for 1A per contact operation.

Q: What is the packaging difference, and does it affect compatibility?

A: The M50-4903345 packaging is unspecified, while the SBH31-NBPB-D33-SM-BK is supplied in tube packaging. Packaging affects handling and storage logistics but does not impact connector form, fit, or function.

Q: Are both parts compliant with current regulatory requirements?

A: Yes. Both connectors are ROHS3 compliant, REACH unaffected, and carry ECCN EAR99 classification. Both maintain MSL 1 (unlimited) moisture sensitivity rating, suitable for standard storage and handling conditions.

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