Ohmite 805F20R Equivalent & Substitute Parts

Part Overview

The Ohmite 805F20R is a 20 Ohms ±1% 5W wirewound chassis mount resistor from the Metal-Mite®89 series, designed for applications requiring precision resistive elements with high power dissipation capability. This component features aluminum housing with flanged mounting and solder lug termination, suitable for chassis-mounted installations in industrial and electronic equipment.

The 805F20R is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or repair requirements for systems utilizing this component.

Substiute Parts

805F20R

OhmiteIn Stock: 747805F20R Datasheet

Current PartRFQ

810F20RE

OhmiteIn Stock: 2144810F20RE Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 805F20R is determined by the following critical parameters:

• Resistance Value: Must be 20 Ohms
• Tolerance: Must be ±1%
• Composition: Must be wirewound
• Temperature Coefficient: Must be ±20ppm/°C
• Operating Temperature Range: Must support -55°C to 275°C
• Housing Type: Must be aluminum
• Mounting Feature: Must include flanges
• Lead Style: Must use solder lugs

The substitute part 810F20RE meets all these criteria. The primary difference is an increased power rating (10W versus 5W), which represents an upward-compatible substitution. The 10W rating provides additional thermal margin and is suitable for applications originally designed for the 5W component, provided mechanical envelope constraints are satisfied.

Parameter Comparison

Engineering Selection Recommendations

The 810F20RE is the manufacturer-recommended substitute for the obsolete 805F20R. Both components are from the same Metal-Mite®89 series and share identical electrical characteristics (20 Ohms, ±1% tolerance, ±20ppm/°C temperature coefficient, -55°C to 275°C operating range).

The 810F20RE offers two significant advantages:

1. Product Availability: The 810F20RE is active in production with substantial inventory availability, whereas the 805F20R is obsolete.

2. Regulatory Compliance: The 810F20RE is ROHS3 compliant, meeting current environmental and regulatory requirements. The 805F20R is RoHS non-compliant.

The 10W power rating of the 810F20RE provides enhanced thermal performance compared to the 5W rating of the 805F20R. This upward-compatible substitution is suitable for all applications where the original 5W component was specified, provided the mechanical envelope accommodates the slightly larger dimensions (0.750" L × 0.812" W × 0.400" H maximum seated height).

Frequently Asked Questions (FAQ)

Q: Can the 810F20RE directly replace the 805F20R in existing designs?

A: Yes, from an electrical standpoint. The 810F20RE maintains identical resistance (20 Ohms), tolerance (±1%), temperature coefficient (±20ppm/°C), and operating temperature range (-55°C to 275°C). Mechanical fit must be confirmed, as the 810F20RE is larger: 0.750" L × 0.812" W versus 0.600" L × 0.646" W for the original part.

Q: What is the significance of the power rating difference (5W vs. 10W)?

A: The 810F20RE's 10W rating indicates higher thermal dissipation capability. This is an upward-compatible change; applications designed for 5W operation will function reliably with the 10W component, with improved thermal margin.

Q: Are there compliance differences between these parts?

A: Yes. The 810F20RE is ROHS3 compliant, while the 805F20R is RoHS non-compliant. For applications subject to RoHS regulations, the 810F20RE is the appropriate choice.

Q: What packaging differences exist?

A: The 805F20R is supplied in box packaging, while the 810F20RE is supplied in tray packaging. This affects handling, storage, and integration into automated assembly processes.

Q: Are both parts from the same manufacturer series?

A: Yes. Both the 805F20R and 810F20RE are from Ohmite's Metal-Mite®89 series, ensuring design consistency and performance characteristics aligned with the same product family specifications.