Ohmite 43F1K8 Equivalent & Substitute Parts

Part Overview

The Ohmite 43F1K8 is a 1.8 kOhms ±1% 3W through-hole resistor with axial wirewound construction, part of the Ohmicone® 40 series. This component is currently active in production and maintains 1,059 units in new original stock. Equivalent and substitute parts are identified when component availability is limited, supply chain disruptions occur, or design flexibility permits alternative sourcing while maintaining electrical and mechanical compatibility.

Substiute Parts

43F1K8

OhmiteIn Stock: 113143F1K8 Datasheet

Current PartRFQ

ALSR031K800FE12

Vishay DaleIn Stock: 889ALSR031K800FE12 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the Ohmite 43F1K8 are qualified based on the following critical parameters:

• Resistance value: 1.8 kOhms (exact match required)
• Tolerance: ±1% (equivalent or tighter tolerance acceptable)
• Power rating: 3W (equal or greater acceptable)
• Composition: Wirewound (maintains thermal and frequency characteristics)
• Package: Axial (mechanical and electrical compatibility)
• Termination count: 2 (circuit interface compatibility)

The Vishay Dale ALSR031K800FE12 meets all substitution criteria with identical electrical specifications and compatible mechanical form factor.

Parameter Comparison

Engineering Selection Recommendations

The Vishay Dale ALSR031K800FE12 is a direct electrical substitute for the Ohmite 43F1K8. Both components share identical resistance, tolerance, and power specifications with wirewound axial construction.

The Vishay Dale part offers ROHS3 compliance, whereas the Ohmite part is RoHS non-compliant. Selection between these parts depends on regulatory requirements for the end application. The Vishay Dale component features moisture-resistant construction and a tighter operating temperature range (-65°C to 250°C), providing enhanced environmental protection in applications requiring such specifications.

Physical dimensions differ slightly: the Vishay Dale part is smaller in both diameter and length. PCB layout and mechanical clearance must be verified before substitution to ensure compatibility with existing mounting patterns and component spacing.

Frequently Asked Questions (FAQ)

Q: Can the Vishay Dale ALSR031K800FE12 replace the Ohmite 43F1K8 in all applications?

A: Electrical substitution is valid for applications where the resistance value (1.8 kOhms), tolerance (±1%), and power rating (3W) are the primary design criteria. Physical dimensions differ, requiring verification of PCB layout and mechanical clearance. RoHS compliance requirements must be evaluated for the specific application.

Q: What is the impact of the different temperature coefficients?

A: The Ohmite part specifies ±20ppm/°C while the Vishay Dale part specifies ±30ppm/°C. For applications with strict temperature stability requirements, the Ohmite part provides superior performance. For general-purpose applications, both coefficients are within acceptable ranges for wirewound resistor technology.

Q: Are the physical dimensions compatible with existing PCB designs?

A: The Vishay Dale part is smaller (0.180" Dia x 0.500" L versus 0.220" Dia x 0.594" L). While the smaller size generally permits installation in existing footprints, PCB layout verification is necessary to confirm adequate clearance and mounting compatibility.

Q: What is the significance of RoHS compliance differences?

A: The Vishay Dale ALSR031K800FE12 is ROHS3 compliant, while the Ohmite 43F1K8 is RoHS non-compliant. Applications subject to RoHS regulations or customer requirements must use the Vishay Dale part. Unrestricted applications may use either component.

Q: How do moisture-resistant features affect component selection?

A: The Vishay Dale part includes moisture-resistant construction with MSL 1 (Unlimited), providing enhanced protection in humid or corrosive environments. The Ohmite part lists MSL as Not Applicable. For applications in high-humidity or marine environments, the Vishay Dale part offers superior reliability.