Equivalent & Substitute Parts for BK/MDA-6-1/4

Part Overview

The BK/MDA-6-1/4 is a 6.25 A, 250 V AC/DC ceramic cartridge fuse manufactured by Eaton - Electronics Division. This fuse operates with slow-blow response characteristics and requires a 3AB or 3AG holder for installation. The component measures 0.250" diameter by 1.250" length (6.35mm x 31.75mm).

The BK/MDA-6-1/4 carries an obsolete product status. Identifying equivalent substitute parts is necessary to maintain circuit protection functionality in applications where this fuse is specified or currently deployed. Active alternatives from both Eaton and Littelfuse manufacturers are available with identical electrical and mechanical parameters.

Substiute Parts

BK/MDA-6-1/4

Eaton - Electronics DivisionIn Stock: 722BK/MDA-6-1/4 Datasheet

Current PartRFQ

BK/MDA-6-1/4-R

Eaton - Electronics DivisionIn Stock: 1106BK/MDA-6-1/4-R Datasheet

DirectRFQ

MDA-6-1/4-R

Eaton - Electronics DivisionIn Stock: 901MDA-6-1/4-R Datasheet

DirectRFQ

03266.25HXP

Littelfuse Inc.In Stock: 79303266.25HXP Datasheet

DirectRFQ

03266.25MXP

Littelfuse Inc.In Stock: 114403266.25MXP Datasheet

DirectRFQ

03266.25VXP

Littelfuse Inc.In Stock: 74903266.25VXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/MDA-6-1/4 is determined by strict equivalence across the following parameters:

Critical Matching Parameters:

• Current Rating: 6.25 A (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Fuse Type: Cartridge, Ceramic (exact match required)
• Response Time: Slow Blow (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required)
• Size / Dimension: 0.250" Dia x 1.250" L (exact match required)
• Mounting Type: Requires Holder (exact match required)

All substitute parts listed below meet these criteria without exception. Secondary parameters such as melting I²t, DC cold resistance, and approval agencies may vary between manufacturers but do not affect functional substitution within the specified electrical and mechanical constraints.

Parameter Comparison

Engineering Selection Recommendations

Eaton Alternatives (Same Manufacturer):

BK/MDA-6-1/4-R and MDA-6-1/4-R are direct Eaton replacements for the obsolete BK/MDA-6-1/4. Both are active products with ROHS3 compliance. MDA-6-1/4-R carries expanded approval certifications (CE, CSA, UL) compared to BK/MDA-6-1/4-R. Selection between these two Eaton variants depends on specific certification requirements for the target application.

Littelfuse Alternatives (Cross-Manufacturer):

The 03266.25HXP, 03266.25MXP, and 03266.25VXP fuses from Littelfuse Series 326 are functionally equivalent substitutes. All three carry identical electrical ratings, mechanical dimensions, and ROHS3 compliance. All three hold CE, CSA, PSE, and UL certifications. These parts are suitable for direct substitution in applications where cross-manufacturer sourcing is acceptable.

Product Status Consideration:

All substitute parts listed carry active product status, ensuring long-term availability and supply chain stability compared to the obsolete BK/MDA-6-1/4.

Frequently Asked Questions (FAQ)

Q: Can BK/MDA-6-1/4 be directly replaced with BK/MDA-6-1/4-R or MDA-6-1/4-R?

A: Yes. Both Eaton alternatives match all critical electrical and mechanical parameters: 6.25 A current rating, 250 V AC voltage rating, ceramic cartridge type, slow-blow response, and 3AB/3AG package dimensions. The primary difference is product status (active versus obsolete) and RoHS compliance level.

Q: Are Littelfuse 03266.25 series fuses compatible with existing 3AB/3AG holders?

A: Yes. The 03266.25HXP, 03266.25MXP, and 03266.25VXP fuses share identical physical dimensions (0.250" diameter x 1.250" length) and package specifications (3AB, 3AG) with the BK/MDA-6-1/4. They install in the same holder hardware without modification.

Q: What is the difference between 03266.25HXP, 03266.25MXP, and 03266.25VXP?

A: All three Littelfuse parts are electrically and mechanically identical for the purposes of substitution. They carry the same 6.25 A rating, 250 V voltage rating, slow-blow response, and 3AB/3AG package. Differences in internal construction or application-specific variants do not affect interchangeability within the specified parameters.

Q: Does the melting I²t value affect substitution compatibility?

A: Melting I²t is a secondary characteristic that varies between manufacturers. The BK/MDA-6-1/4 does not specify this parameter. Littelfuse parts specify 60.4 A²s, while Eaton alternatives specify 37.2 A²s or 90 A²s. These variations do not prevent functional substitution when all primary electrical and mechanical parameters match.

Q: Are all substitute parts RoHS compliant?

A: The original BK/MDA-6-1/4 is RoHS non-compliant. All active substitute parts (BK/MDA-6-1/4-R, MDA-6-1/4-R, 03266.25HXP, 03266.25MXP, 03266.25VXP) are ROHS3 compliant, meeting current environmental regulations.

Q: Which substitute part has the broadest certification coverage?

A: MDA-6-1/4-R (Eaton) and all three Littelfuse 03266.25 variants carry CE, CSA, and UL certifications. The Littelfuse parts additionally hold PSE certification. BK/MDA-6-1/4-R does not list specific approval agencies in the provided data.