Ohmite 43F40R Equivalent & Substitute Parts

Part Overview

The Ohmite 43F40R is a 40 Ohm ±1% 3W through-hole resistor with axial wirewound composition, part of the Ohmicone® 40 series. This component is currently active in production. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and design continuity when the primary part number becomes unavailable or when alternative packaging or compliance requirements necessitate component substitution.

Substiute Parts

43F40R

OhmiteIn Stock: 67843F40R Datasheet

Current PartRFQ

43F40RE

OhmiteIn Stock: 568643F40RE Datasheet

DirectRFQ

ALSR0340R00FE12

Vishay DaleIn Stock: 840ALSR0340R00FE12 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the Ohmite 43F40R is determined by the following core parameters:

• Resistance value: 40 Ohms
• Tolerance: ±1%
• Power rating: 3W
• Composition: Wirewound
• Package configuration: Axial through-hole
• Termination count: 2

Parts meeting all these criteria are classified as direct substitutes. The Ohmite 43F40RE and Vishay Dale ALSR0340R00FE12 satisfy these requirements. Variations in temperature coefficient, physical dimensions, and compliance certifications do not disqualify substitution but must be evaluated within the context of specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

All three parts—43F40R, 43F40RE, and ALSR0340R00FE12—are active products suitable for 40 Ohm ±1% 3W axial wirewound resistor applications.

The Ohmite 43F40RE is a direct equivalent to the 43F40R with identical electrical specifications and physical dimensions. The primary distinction is packaging format (Bulk vs. standard) and RoHS3 compliance status. Selection between these two Ohmite variants depends on procurement requirements and regulatory compliance mandates.

The Vishay Dale ALSR0340R00FE12 is electrically equivalent with the same resistance, tolerance, and power rating. Physical dimensions are smaller (0.180" Dia x 0.500" L versus 0.220" Dia x 0.594" L), and the temperature coefficient is ±30ppm/°C compared to ±20ppm/°C for the Ohmite parts. This component includes moisture-resistant construction and carries ROHS3 compliance. Selection of the Vishay Dale part requires verification that the reduced physical dimensions are compatible with board layout and that the higher temperature coefficient is acceptable for the application.

Frequently Asked Questions (FAQ)

Q: Can the Ohmite 43F40RE directly replace the Ohmite 43F40R?

A: Yes. The 43F40RE is electrically and mechanically identical to the 43F40R. Both are 40 Ohm ±1% 3W axial wirewound resistors with identical dimensions and temperature coefficients. The primary difference is packaging format and RoHS compliance status.

Q: Is the Vishay Dale ALSR0340R00FE12 a suitable substitute for the Ohmite 43F40R?

A: The ALSR0340R00FE12 meets the core electrical requirements: 40 Ohm resistance, ±1% tolerance, and 3W power rating in axial wirewound configuration. However, physical dimensions are smaller, and the temperature coefficient is ±30ppm/°C versus ±20ppm/°C. Verify that these differences are acceptable for your specific application before substitution.

Q: What are the key parameters that determine substitution compatibility?

A: Substitution compatibility is determined by resistance value (40 Ohms), tolerance (±1%), power rating (3W), composition (wirewound), package type (axial), and termination count (2). All substitute parts listed meet these criteria.

Q: Does RoHS compliance affect substitution decisions?

A: RoHS compliance is a regulatory and procurement consideration. The 43F40R is RoHS non-compliant, while the 43F40RE and ALSR0340R00FE12 are ROHS3 compliant. If your application or supply chain requires RoHS compliance, select the 43F40RE or ALSR0340R00FE12 accordingly.

Q: Are there physical dimension constraints when substituting with the Vishay Dale part?

A: Yes. The ALSR0340R00FE12 has smaller dimensions (0.180" Dia x 0.500" L) compared to the Ohmite parts (0.220" Dia x 0.594" L). Verify that the reduced size is compatible with your PCB layout and mechanical assembly before substitution.