Ohmite 40F250 Equivalent & Substitute Parts

Part Overview

The Ohmite 40F250 is a 250 Ohm, ±1% tolerance, 10W axial wirewound through-hole resistor from the Ohmicone® 40 series. This component is classified as Active product status and remains in production. Equivalent and substitute parts are identified when original stock availability is limited or when specific compliance requirements must be met for new designs or procurement cycles.

Substiute Parts

40F250

OhmiteIn Stock: 115640F250 Datasheet

Current PartRFQ

40F250E

OhmiteIn Stock: 90540F250E Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 40F250 are identified based on electrical and mechanical parameter equivalence. The primary substitution criterion is exact matching of resistance value (250 Ohms), tolerance (±1%), power rating (10W), composition (wirewound), and package configuration (axial). All substitute parts must maintain identical physical dimensions and termination count to ensure direct board-level compatibility without layout modifications.

The 40F250E is classified as a parametric equivalent because it matches all critical electrical specifications and physical form factor. The distinction between the main part and its substitute is packaging configuration and RoHS compliance status, not functional performance.

Parameter Comparison

Engineering Selection Recommendations

The 40F250E serves as a direct functional substitute for the 40F250 in applications where ROHS3 compliance is required. Both parts are Active status components from the same Ohmicone® 40 series and deliver identical electrical performance. Selection between these parts should be based on regulatory requirements: the 40F250 for legacy systems or non-regulated applications, and the 40F250E for new designs subject to RoHS3 directives. Packaging format (standard versus bulk) may influence procurement decisions based on order quantity and inventory management practices.

Frequently Asked Questions (FAQ)

Q: Can the 40F250E replace the 40F250 in existing designs? A: Yes. The 40F250E is electrically and mechanically identical to the 40F250. Both parts share the same resistance value, tolerance, power rating, temperature coefficient, and axial package dimensions. Direct substitution is possible without circuit redesign or board layout modification.

Q: What is the difference between the 40F250 and 40F250E? A: The primary differences are packaging format and RoHS compliance status. The 40F250 is supplied in standard packaging and is RoHS non-compliant. The 40F250E is supplied in bulk packaging and meets ROHS3 compliance requirements. Electrical and mechanical specifications are identical.

Q: Are there any compatibility concerns when substituting the 40F250E for the 40F250? A: No compatibility concerns exist. Both parts are axial wirewound resistors with identical physical dimensions (0.406" Dia x 1.902" L), two terminations, and mounting footprints. They are interchangeable at the component level.

Q: Which part should be selected for new product designs? A: For new designs subject to RoHS3 regulations, the 40F250E is the appropriate selection. For applications without RoHS compliance requirements, either part may be used based on availability and procurement preferences.

Q: Does packaging format affect electrical performance? A: No. Packaging format (standard versus bulk) is a logistics and supply chain consideration only. It does not affect the electrical characteristics, reliability, or performance of the resistor component itself.