Equivalent & Substitute Parts for 5ST 315

Part Overview

The Bel Fuse Inc. 5ST 315 is a 315 mA, 250 V AC/DC slow blow glass cartridge fuse in 5mm x 20mm package format requiring a holder for installation. This part carries an obsolete product status, making identification of active equivalent and substitute components essential for ongoing system maintenance and new design implementations. The 5ST 315 series has been superseded by newer product lines with improved compliance certifications and active manufacturing support.

Substiute Parts

5ST 315

Bel Fuse Inc.In Stock: 9055ST 315 Datasheet

Current PartRFQ

5ST 315-R

Bel Fuse Inc.In Stock: 176095ST 315-R Datasheet

DirectRFQ

0034.3112

SCHURTER Inc.In Stock: 60520034.3112 Datasheet

DirectRFQ

0218.315HXP

Littelfuse Inc.In Stock: 9640218.315HXP Datasheet

DirectRFQ

0218.315MXBP

Littelfuse Inc.In Stock: 9680218.315MXBP Datasheet

DirectRFQ

0218.315MXP

Littelfuse Inc.In Stock: 88580218.315MXP Datasheet

DirectRFQ

0218.315TXP

Littelfuse Inc.In Stock: 8690218.315TXP Datasheet

DirectRFQ

0218.315VXP

Littelfuse Inc.In Stock: 9100218.315VXP Datasheet

DirectRFQ

0034.2511

SCHURTER Inc.In Stock: 18210034.2511 Datasheet

SimilarRFQ

0213.315MXP

Littelfuse Inc.In Stock: 21260213.315MXP Datasheet

SimilarRFQ

BK1/GMD-315-R

Eaton - Electronics DivisionIn Stock: 717BK1/GMD-315-R Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by strict alignment with the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Current Rating: 315 mA (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Response Time: Slow Blow (exact match required)
• Package / Case: 5mm x 20mm (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Mounting Type: Requires Holder (exact match required)

Secondary Compatibility Factors:

• Breaking Capacity @ Rated Voltage: 35 A minimum
• Operating Temperature Range: -55°C to 125°C or equivalent
• Melting I²t: Acceptable variance within thermal response envelope

Parts are classified as Direct Substitutes when all primary criteria match exactly. Parts are classified as Similar when they meet primary electrical criteria but may have minor variations in secondary parameters such as melting I²t, DC cold resistance, or approval agency certifications.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Recommended Priority Order):

1. 5ST 315-R (Bel Fuse Inc.) — Identical electrical and mechanical specifications to the original 5ST 315. Active product status with ROHS3 compliance. Highest compatibility assurance. Approval agencies expanded to include CCC, cURus, and PSE.

2. 0218.315MXP (Littelfuse Inc.) — Meets all primary substitution criteria. Active status with comprehensive approval certifications (CCC, CE, CSA, K-MARK, SEMKO, UL, VDE). Melting I²t of 1.11 provides acceptable thermal response within slow blow envelope. Largest inventory availability (8,839 units).

3. 0218.315HXP (Littelfuse Inc.) — Functionally equivalent with identical electrical parameters. Active status with broad certification coverage. Melting I²t of 1.11 maintains slow blow response characteristics.

4. 0034.3112 (SCHURTER Inc.) — Direct electrical match with 315 mA, 250 V AC, slow blow response. Active status with ROHS3 compliance. Melting I²t of 0.544 represents acceptable variance. Approval agencies: CCC, cURus, VDE.

Similar Parts (Application-Dependent):

5. 0034.2511 (SCHURTER Inc.) — Shares 315 mA current rating and 250 V AC voltage with 5mm x 20mm package. Response time is Medium Blow rather than Slow Blow, and DC voltage rating is specified at 125 V. Breaking capacity is 80 A. Use only when medium blow response is acceptable for the application.

6. 0213.315MXP (Littelfuse Inc.) — Meets all primary criteria with slow blow response. Active status with ROHS3 compliance. Melting I²t of 1.14 is within acceptable range. Approval agencies include BSI, CCC, CE, CSA, SEMKO, UR, VDE.

7. BK1/GMD-315-R (Eaton - Electronics Division) — Electrical and mechanical match with 315 mA, 250 V AC, slow blow, 5mm x 20mm. Active status with ROHS3 compliance. Approval agencies: CSA, UL. Melting I²t of 0.89 is acceptable.

Additional Littelfuse 218 Series Options:

8. 0218.315MXBP (Littelfuse Inc.) — Identical specifications to 0218.315MXP with approval agencies including KC. Melting I²t of 1.11.

9. 0218.315TXP (Littelfuse Inc.) — Equivalent to other 218 series variants with melting I²t of 1.11 and approval agencies including KC.

10. 0218.315VXP (Littelfuse Inc.) — Functionally identical to other 218 series slow blow variants with melting I²t of 1.11.

All recommended direct substitutes are active products with ROHS3 compliance, addressing the obsolete status of the original 5ST 315.

Frequently Asked Questions (FAQ)

Q: Can I use 0034.2511 as a direct replacement for 5ST 315?

A: No. While 0034.2511 matches the 315 mA current rating, 250 V AC voltage, and 5mm x 20mm package, it has a Medium Blow response time instead of Slow Blow. This difference in response time affects circuit protection characteristics and makes it unsuitable as a direct substitute unless your application specifically requires medium blow response.

Q: What is the difference between the Littelfuse 218 series variants (0218.315HXP, 0218.315MXBP, 0218.315MXP, 0218.315TXP, 0218.315VXP)?

A: All five variants share identical electrical specifications: 315 mA, 250 V AC, slow blow response, 5mm x 20mm package, and melting I²t of 1.11. The primary differences are in approval agency certifications. 0218.315MXP and 0218.315HXP include K-MARK certification. 0218.315MXBP, 0218.315TXP, and 0218.315VXP include KC certification. Selection depends on regional regulatory requirements.

Q: Why does 0034.3112 have a different melting I²t (0.544) compared to Littelfuse parts (1.11)?

A: Melting I²t represents the thermal energy required to melt the fuse element. Different manufacturers use different fuse element designs and materials, resulting in different I²t values. Both values are acceptable for 315 mA slow blow fuses at 250 V AC, as they fall within the slow blow response envelope. The choice between them depends on specific circuit protection requirements and thermal characteristics of your application.

Q: Is the 5ST 315-R a true equivalent to the obsolete 5ST 315?

A: Yes. The 5ST 315-R is the active replacement from the same manufacturer (Bel Fuse Inc.). It maintains identical electrical and mechanical specifications while adding ROHS3 compliance and expanded approval certifications. This is the recommended first choice for direct replacement.

Q: Can I substitute parts from different manufacturers?

A: Yes, provided all primary electrical and mechanical parameters match exactly: 315 mA current rating, 250 V AC voltage, slow blow response time, 5mm x 20mm package, and 35 A breaking capacity. Cross-manufacturer substitution is standard practice in electronics engineering when specifications align. Verify approval certifications meet your regional requirements.

Q: What does "Requires Holder" mean for mounting type?

A: These are cartridge fuses that must be installed in a dedicated fuse holder or clip assembly. They are not soldered directly to circuit boards. Ensure your existing fuse holder is compatible with the 5mm x 20mm package format before substitution.

Q: Why do some parts show different DC cold resistance values?

A: DC cold resistance varies based on fuse element material and design. The original 5ST 315 shows 1.3 Ohms, while Littelfuse parts show 0.8475 Ohms, and Eaton shows 2.4 Ohms. These variations do not affect substitutability for AC/DC fuse applications at the specified ratings. DC cold resistance becomes relevant only in specialized low-voltage DC circuits where voltage drop is critical.

Q: Are all recommended substitutes RoHS compliant?

A: All active substitute parts listed are ROHS3 compliant. The original 5ST 315 is marked as RoHS non-compliant. If RoHS compliance is a requirement for your application or region, select from the active substitute options.