45F25R Equivalent & Substitute Parts Reference

Part Overview

The Ohmite 45F25R is a 25 Ohm, ±1% tolerance, 5W axial wirewound through-hole resistor from the Ohmicone® 40 series. This component is currently active in production with 808 units in stock. Equivalent and substitute parts are identified based on matching electrical specifications (resistance value, tolerance, power rating, and composition) and mechanical compatibility (axial package, terminal configuration). Alternative sources become necessary for supply chain optimization, compliance requirements, or specific application needs such as moisture resistance or RoHS compliance.

Substiute Parts

45F25R

OhmiteIn Stock: 82645F25R Datasheet

Current PartRFQ

45F25RE

OhmiteIn Stock: 120345F25RE Datasheet

DirectRFQ

ALSR0525R00FE12

Vishay DaleIn Stock: 976ALSR0525R00FE12 Datasheet

DirectRFQ

RS00525R00FS73

Vishay DaleIn Stock: 2589RS00525R00FS73 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following criteria:

Electrical Compatibility Requirements:

• Resistance value: 25 Ohms (exact match required)
• Tolerance: ±1% (exact match required)
• Power rating: 5W (exact match required)
• Composition: Wirewound (exact match required)

Mechanical Compatibility Requirements:

• Package: Axial (exact match required)
• Terminations: 2 (exact match required)

Acceptable Variations:

• Temperature coefficient: ±20ppm/°C to ±30ppm/°C (within engineering tolerance for general applications)
• Operating temperature range: May exceed the main part's range without affecting substitution validity
• Physical dimensions: Minor variations acceptable within axial package standards (0.312" to 0.343" diameter; 0.875" to 0.937" length)
• Moisture resistance: Additional feature that enhances performance without affecting core substitution
• Packaging format: Bulk or Cut Tape formats are interchangeable for component-level selection

All three substitute parts meet these criteria and are direct functional equivalents.

Parameter Comparison

Engineering Selection Recommendations

45F25RE (Ohmite): Direct equivalent from the same manufacturer and series. Identical electrical and mechanical specifications. Offers ROHS3 compliance upgrade over the main part. Recommended for applications requiring RoHS compliance with no design changes.

ALSR0525R00FE12 (Vishay Dale): Functionally equivalent with slightly higher temperature coefficient (±30ppm/°C vs. ±20ppm/°C). Includes moisture-resistant construction and specified operating temperature range (-65°C ~ 250°C). Slightly smaller physical dimensions (0.312" diameter vs. 0.343"). ROHS3 compliant. Suitable for applications requiring enhanced environmental protection and compliance certification.

RS00525R00FS73 (Vishay Dale): Functionally equivalent with matching temperature coefficient (±20ppm/°C). Includes moisture-resistant construction and specified operating temperature range (-65°C ~ 250°C). Slightly smaller physical dimensions (0.312" diameter vs. 0.343"). Highest inventory availability (2480 units). RoHS non-compliant, matching the main part's compliance status. Recommended for high-volume applications where moisture resistance is required and RoHS compliance is not a constraint.

Frequently Asked Questions (FAQ)

Q: Can I use 45F25RE as a direct drop-in replacement for 45F25R?

A: Yes. The 45F25RE is electrically and mechanically identical to the 45F25R. Both are from Ohmite's Ohmicone® 40 series with identical resistance (25 Ohms), tolerance (±1%), power rating (5W), temperature coefficient (±20ppm/°C), and axial package dimensions (0.343" Dia x 0.937" L). The primary difference is packaging format (Bulk vs. standard) and RoHS3 compliance status of the 45F25RE.

Q: What are the dimensional differences between Ohmite and Vishay Dale substitutes?

A: Ohmite parts (45F25R and 45F25RE) measure 0.343" diameter x 0.937" length. Vishay Dale parts (ALSR0525R00FE12 and RS00525R00FS73) measure 0.312" diameter x 0.875" length. Both are axial wirewound resistors and fit standard through-hole PCB layouts, though the slightly smaller Vishay Dale dimensions may provide marginal space advantages in compact designs.

Q: Which substitute offers the best compliance certifications?

A: Both 45F25RE and ALSR0525R00FE12 are ROHS3 compliant. If RoHS compliance is required, either of these parts is suitable. The main part (45F25R) and RS00525R00FS73 are RoHS non-compliant.

Q: Are the Vishay Dale substitutes moisture resistant?

A: Yes. Both ALSR0525R00FE12 and RS00525R00FS73 feature moisture-resistant construction. The Ohmite parts (45F25R and 45F25RE) do not specify moisture resistance. For applications exposed to humidity or condensation, Vishay Dale substitutes provide enhanced environmental protection.

Q: What is the temperature coefficient difference, and does it matter?

A: The main part and most substitutes have a temperature coefficient of ±20ppm/°C. The ALSR0525R00FE12 has ±30ppm/°C. This 10ppm/°C difference is negligible for most general-purpose applications. For precision circuits requiring tight temperature stability, the ±20ppm/°C parts (45F25R, 45F25RE, RS00525R00FS73) are preferred.

Q: Which substitute has the highest inventory availability?

A: RS00525R00FS73 has the highest inventory with 2480 units in stock, followed by 45F25RE with 1129 units, and ALSR0525R00FE12 with 879 units.

**Q: Can I use these