5MT 4.6-R Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The 5MT 4.6-R is a 4.6 A, 125 V AC/DC glass cartridge fuse manufactured by Bel Fuse Inc. in a 5mm x 20mm package format. This component is classified as obsolete, necessitating identification of active equivalent and substitute parts for ongoing system maintenance and new designs. The fuse requires a dedicated holder for installation and provides medium-blow response characteristics suitable for general circuit protection applications.

Substiute Parts

5MT 3.5-R

Bel Fuse Inc.In Stock: 8775MT 3.5-R Datasheet

Current PartRFQ

023403.5MXP

Littelfuse Inc.In Stock: 7633023403.5MXP Datasheet

DirectRFQ

BK1/GMC-3.5-R

Eaton - Electronics DivisionIn Stock: 1927BK1/GMC-3.5-R Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 5MT 4.6-R is determined by the following critical parameters:

• Current Rating: 4.6 A (exact match required)
• Package / Case: 5mm x 20mm (physical compatibility with existing holders)
• Fuse Type: Cartridge, Glass (functional form factor)
• Response Time: Medium Blow (circuit protection characteristic)
• Mounting Type: Requires Holder (installation method)

Substitute parts are classified into two categories:

Direct Substitute (Voltage-Rated Upgrade): 023404.6MXP by Littelfuse Inc. matches all critical parameters with an elevated voltage rating of 250 V AC, providing enhanced protection margin in 125 V applications while maintaining identical current rating, package dimensions, and response characteristics.

Equivalent Substitute (Identical Electrical Specification): BK1/GMC-4.6-R by Eaton - Electronics Division provides exact electrical and mechanical compatibility with the original 5MT 4.6-R, including matching 125 V AC rating, 10 kA breaking capacity, and identical package format.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Preferred): BK1/GMC-4.6-R by Eaton - Electronics Division is the primary substitute. This part maintains identical electrical specifications (4.6 A, 125 V AC) and mechanical compatibility with the 5MT 4.6-R. Both parts carry equivalent regulatory approvals (CSA, UL) and RoHS3 compliance. The Eaton part is currently in active production with substantial inventory availability (1905 pcs).

For Voltage-Margin Applications: 023404.6MXP by Littelfuse Inc. serves as an alternative where elevated voltage rating (250 V AC) provides additional safety margin. This part maintains identical current rating, package dimensions, and response characteristics. The higher voltage rating does not affect operation in 125 V circuits and may be preferred in applications requiring enhanced overvoltage protection. This part carries broader regulatory approvals (CE, CSA, K-MARK, PSE, UL) and is actively produced with high inventory (7541 pcs).

Both substitute parts are RoHS3 compliant and REACH unaffected, matching the environmental compliance profile of the original component.

Frequently Asked Questions (FAQ)

Q: Can 023404.6MXP be used in place of 5MT 4.6-R? A: Yes. The 023404.6MXP maintains the same current rating (4.6 A), package dimensions (5mm x 20mm), response time (medium blow), and fuse type (cartridge, glass). The elevated voltage rating (250 V vs. 125 V) does not prevent operation in 125 V circuits and provides additional protection margin.

Q: Is BK1/GMC-4.6-R a direct equivalent to 5MT 4.6-R? A: Yes. The BK1/GMC-4.6-R provides identical electrical specifications (4.6 A, 125 V AC), breaking capacity (10 kA), package format (5mm x 20mm), and response characteristics (medium blow). This part is the closest functional equivalent.

Q: Will these substitutes fit existing fuse holders designed for 5MT 4.6-R? A: Yes. All substitute parts use the standard 5mm x 20mm cartridge format and are compatible with holders designed for this package size. Physical dimensions are within tolerance for standard holder compatibility.

Q: What is the difference in melting I²t values between these parts? A: Melting I²t indicates thermal energy required to melt the fuse element. The 5MT 4.6-R (76), 023404.6MXP (36.275), and BK1/GMC-4.6-R (25) show variation in thermal response. All three parts maintain the same current rating and response classification (medium blow), indicating these differences fall within acceptable operating parameters for the 4.6 A circuit protection function.

Q: Are all substitute parts RoHS3 compliant? A: Yes. The 5MT 4.6-R, 023404.6MXP, and BK1/GMC-4.6-R are all RoHS3 compliant and REACH unaffected.

Q: Which substitute has the best availability? A: 023404.6MXP by Littelfuse Inc. has the highest inventory (7541 pcs), followed by BK1/GMC-4.6-R by Eaton (1905 pcs). Both are in active production.