Molex 0399000521 Terminal Block Header – Equivalent & Substitute Parts

Part Overview

The Molex 0399000521 is a 21-position terminal block header with male pins, shrouded on four sides, featuring a 0.150" (3.81mm) pitch and vertical through-hole mounting. This component is classified as obsolete, making identification of active equivalent parts essential for ongoing production and maintenance applications. Substitute parts must maintain electrical and mechanical compatibility across the same pitch, position count, and mounting configuration.

Substiute Parts

0399000521

MolexIn Stock: 11860399000521 Datasheet

Current PartRFQ

A-TB381-OQ21CV

Assmann WSW ComponentsIn Stock: 743A-TB381-OQ21CV Datasheet

MFR RecommendedRFQ

OQ2132000000G

Amphenol AnytekIn Stock: 1040OQ2132000000G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the Molex 0399000521 is determined by the following critical parameters:

• Position Count & Pitch: All substitutes must maintain 21 positions at 0.150" (3.81mm) pitch to ensure mechanical and electrical compatibility with mating connectors.
• Type & Orientation: Header configuration must be male pins, shrouded (4 side), vertical orientation to match PCB layout and assembly requirements.
• Termination & Mounting: Solder termination and through-hole mounting are mandatory for direct replacement in existing designs.
• Electrical Ratings: Voltage rating of 300 V UL is maintained across all substitutes. Current rating may vary within acceptable operational limits.
• Compliance: All substitutes must maintain ROHS3 compliance and MSL 1 (Unlimited) moisture sensitivity rating.

The two active equivalent parts identified—Assmann WSW Components A-TB381-OQ21CV and Amphenol Anytek OQ2132000000G—meet all critical substitution criteria and are available in production quantities.

Parameter Comparison

Engineering Selection Recommendations

Both substitute parts are active production components with full ROHS3 compliance and MSL 1 ratings, ensuring regulatory and environmental compatibility with the obsolete Molex 0399000521.

Assmann WSW Components A-TB381-OQ21CV is suitable for applications where the 10 A current rating is sufficient. This part features UL94 V-0 flammability rating and operates across -40°C to 115°C, providing enhanced thermal performance for demanding environments.

Amphenol Anytek OQ2132000000G is recommended for applications requiring black housing color matching or where the OQ series integration is preferred. This part also carries UL94 V-0 flammability rating and identical operating temperature range (-40°C to 115°C).

Both substitutes exhibit insulation heights within 0.01" (0.25mm) of the original specification, ensuring compatibility with standard PCB layouts and mating connector tolerances. The current rating reduction from 12 A to 10 A should be evaluated against actual circuit requirements; if 12 A capacity is mandatory, alternative sourcing strategies may be necessary.

Frequently Asked Questions (FAQ)

Q: Can the Assmann A-TB381-OQ21CV or Amphenol OQ2132000000G be used as direct replacements for the Molex 0399000521?

A: Yes, both parts are direct mechanical and electrical substitutes. They maintain identical position count (21), pitch (0.150"), type (male pins, shrouded), orientation (vertical), and termination method (solder through-hole). All three parts are ROHS3 compliant with MSL 1 ratings.

Q: What is the significance of the current rating difference (12 A vs. 10 A)?

A: The Molex 0399000521 is rated for 12 A UL current, while both substitutes are rated for 10 A UL. This difference should be evaluated against the actual current requirements of the application. If the circuit operates below 10 A, substitution is straightforward. If sustained currents above 10 A are required, alternative parts must be sourced.

Q: Are there differences in housing material between the original and substitutes?

A: The Molex 0399000521 uses Polybutylene Terephthalate (PBT) housing, while both substitutes use Thermoplastic housing. Both materials are suitable for standard terminal block applications and maintain equivalent mechanical and thermal properties for this product category.

Q: Do the insulation height variations affect PCB compatibility?

A: The insulation height difference is minimal (0.363" vs. 0.362", or 0.01" / 0.25mm). This variation is within standard PCB layout tolerances and does not affect mating connector alignment or assembly procedures.

Q: What is the contact tail length specification, and why is it not provided for the Molex part?

A: Contact tail length (0.138" / 4.60mm) is specified for both substitutes but not documented for the Molex 0399000521. This parameter defines the solder tail depth into the PCB. The substitutes' tail length is standard for 3.81mm pitch terminal blocks and is compatible with conventional through-hole PCB designs.

Q: Are both substitutes available in equivalent packaging quantities?

A: Both substitutes are available in bulk packaging with substantial inventory: Assmann A-TB381-OQ21CV (691 pcs) and Amphenol OQ2132000000G (1025 pcs). Packaging format is consistent across both alternatives.