F40J50R Equivalent & Substitute Parts

Part Overview

The F40J50R is a 50 Ohms ±5% 40W wirewound chassis mount resistor manufactured by Ohmite, part of the Stackohm® 250 series. This component is designed for high-power applications requiring stable resistance performance across extended temperature ranges. The part is currently active in production with 666 units in stock. Equivalent and substitute parts are identified based on matching electrical specifications and mechanical compatibility within the allowed parameter tolerances for this resistor category.

Substiute Parts

F40J50R

OhmiteIn Stock: 741F40J50R Datasheet

Current PartRFQ

F30J50RE

OhmiteIn Stock: 767F30J50RE Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the F40J50R are identified based on electrical parameter equivalence within the wirewound chassis mount resistor category. The primary substitution criteria are:

• Identical resistance value: 50 Ohms
• Matching tolerance: ±5%
• Equivalent temperature coefficient: ±260ppm/°C
• Compatible operating temperature range: -55°C ~ 350°C
• Identical composition: Wirewound
• Matching coating and housing: Vitreous Enamel Coated
• Compatible mounting: Flange Braces, Right Angle
• Matching lead style: Solder Lugs
• Compatible package: Radial, Flat Oval

The F30J50RE meets these electrical and mechanical criteria. The primary difference is the power rating (30W versus 40W), which represents a lower power capacity. This part is suitable for applications where the full 40W rating is not required.

Parameter Comparison

Engineering Selection Recommendations

The F30J50RE is electrically and mechanically equivalent to the F40J50R for applications requiring 50 Ohms ±5% resistance with wirewound composition and the specified temperature performance. Selection between these parts depends on application power requirements and regulatory compliance needs.

The F40J50R is suitable for applications requiring the full 40W power dissipation capacity. The F30J50RE is suitable for applications where power dissipation does not exceed 30W. Both parts maintain identical electrical characteristics including resistance value, tolerance, temperature coefficient, and operating temperature range.

The F30J50RE offers ROHS3 compliance, whereas the F40J50R is RoHS non-compliant. For applications subject to RoHS regulations, the F30J50RE is the appropriate selection when power requirements do not exceed 30W.

Frequently Asked Questions (FAQ)

Q: Can the F30J50RE replace the F40J50R in all applications?

A: The F30J50RE is electrically equivalent to the F40J50R for resistance value, tolerance, temperature coefficient, and operating temperature range. Substitution is valid only when the application power dissipation does not exceed 30W. If the circuit requires power dissipation above 30W, the F40J50R must be used.

Q: What is the physical size difference between these parts?

A: The F40J50R measures 2.000" L x 1.000" W (50.80mm x 25.40mm). The F30J50RE measures 1.250" L x 1.000" W (31.75mm x 25.40mm). Both parts have identical height when seated at 0.563" (14.29mm). The smaller footprint of the F30J50RE may provide layout advantages in space-constrained designs.

Q: Are the mounting and lead configurations identical?

A: Yes. Both parts feature flange braces with right-angle mounting and solder lugs for connection. The package type is radial, flat oval for both parts, ensuring mechanical compatibility in existing designs.

Q: What is the difference in RoHS compliance?

A: The F40J50R is RoHS non-compliant. The F30J50RE is ROHS3 compliant. For applications subject to RoHS directives, the F30J50RE is the compliant option when power requirements permit its use.

Q: Are both parts from the same manufacturer and series?

A: Yes. Both the F40J50R and F30J50RE are manufactured by Ohmite and are part of the Stackohm® 250 series, ensuring consistent design and performance characteristics.