UB3C-18RF8 Equivalent & Substitute Parts

Part Overview

The UB3C-18RF8 is an 18 Ohm ±1% 3W axial wirewound resistor manufactured by Riedon in the UB series. This component is designed for through-hole applications requiring current sensing functionality with enhanced reliability features including flame proof, moisture resistant, pulse withstanding, and safety certifications. The part is currently active in production with 949 units in stock. Substitute parts are necessary to address supply chain flexibility, alternative packaging requirements, or inventory availability across different manufacturers while maintaining equivalent electrical and mechanical performance.

Substiute Parts

UB3C-18RF8

RiedonIn Stock: 970UB3C-18RF8 Datasheet

Current PartRFQ

43F18RE

OhmiteIn Stock: 215743F18RE Datasheet

MFR RecommendedRFQ

RS02B18R00FE70

Vishay DaleIn Stock: 1677RS02B18R00FE70 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the UB3C-18RF8 is determined by strict equivalence across the following parameters: resistance value (18 Ohms), tolerance (±1%), power rating (3W), composition (wirewound), package type (axial), temperature coefficient (±20ppm/°C), and compliance certifications (ROHS3). All identified substitute parts meet these core electrical and mechanical requirements. Physical dimensions may vary within acceptable limits for axial through-hole mounting. Operating temperature ranges may extend beyond the main part specification without affecting substitution validity. Packaging format (Tape & Reel, Bulk, or Cut Tape) does not affect electrical equivalence but may impact procurement and assembly workflows.

Parameter Comparison

Engineering Selection Recommendations

All three parts—UB3C-18RF8, 43F18RE, and RS02B18R00FE70—are electrically equivalent and meet ROHS3 compliance requirements. Selection between these parts should be based on the following factors:

The UB3C-18RF8 offers the smallest physical footprint (4.00mm diameter x 8.90mm length) and is supplied in Tape & Reel packaging, making it suitable for automated assembly processes. It includes documented current sense, flame proof, moisture resistant, pulse withstanding, and safety features.

The 43F18RE (Ohmite Ohmicone® 40 series) is available in bulk packaging with a larger physical envelope (5.60mm diameter x 15.10mm length). This part is suitable for applications where packaging format flexibility is required.

The RS02B18R00FE70 (Vishay Dale RS series) provides an extended operating temperature range (-65°C ~ 250°C) compared to the main part and includes documented moisture resistant features. It is supplied in Cut Tape format and represents a mid-size option (4.75mm diameter x 14.22mm length).

Physical dimension variations require verification against PCB layout constraints and mechanical clearance requirements in the target application.

Frequently Asked Questions (FAQ)

Q: Can the 43F18RE substitute for the UB3C-18RF8 in all applications?

A: Yes, electrically the 43F18RE is equivalent. However, the larger physical dimensions (5.60mm diameter x 15.10mm length versus 4.00mm x 8.90mm) must be verified against PCB layout and mechanical clearance constraints. The bulk packaging format differs from the Tape & Reel format of the main part.

Q: What is the difference between the RS02B18R00FE70 and the UB3C-18RF8?

A: Both parts are electrically equivalent with identical resistance, tolerance, power rating, and temperature coefficient. The RS02B18R00FE70 offers an extended lower operating temperature limit (-65°C versus -55°C) and is supplied in Cut Tape packaging rather than Tape & Reel. Physical dimensions differ slightly (4.75mm diameter x 14.22mm length).

Q: Are all substitute parts ROHS3 compliant?

A: Yes, all three parts—UB3C-18RF8, 43F18RE, and RS02B18R00FE70—are ROHS3 compliant.

Q: Does packaging format affect electrical performance?

A: No. Tape & Reel, Bulk, and Cut Tape formats are packaging and delivery methods only and do not affect electrical characteristics or performance.

Q: Which part should I select if PCB space is limited?

A: The UB3C-18RF8 has the smallest physical footprint (4.00mm diameter x 8.90mm length) and is the optimal choice for space-constrained applications.

Q: Can I use the RS02B18R00FE70 in applications requiring operation below -55°C?

A: Yes. The RS02B18R00FE70 is rated for -65°C ~ 250°C, extending the lower temperature limit by 10°C compared to the UB3C-18RF8 (-55°C ~ 250°C).