ROX1SF18K Equivalent & Substitute Parts

Part Overview

The ROX1SF18K is an 18 kOhms ±1% 1W through-hole axial resistor manufactured by TE Connectivity Passive Product. This component features metal oxide film construction with flame-proof and pulse-withstanding characteristics, designed for applications requiring safety-rated passive components. The product is currently obsolete, necessitating identification of functionally equivalent alternatives that maintain the same electrical and mechanical specifications for continued system support and new designs.

Substiute Parts

ROX1SF18K

TE Connectivity Passive ProductIn Stock: 834ROX1SF18K Datasheet

Current PartRFQ

FMF1WSFRF52-18K

YAGEOIn Stock: 946FMF1WSFRF52-18K Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ROX1SF18K is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Requirements:

• Resistance value: 18 kOhms (exact match)
• Tolerance: ±1% (exact match)
• Power rating: 1W (exact match)

Mechanical Equivalence Requirements:

• Package configuration: Axial through-hole (exact match)
• Number of terminations: 2 (exact match)

Safety and Compliance Requirements:

• Flame-proof characteristic (required)
• Safety-rated construction (required)

The substitute part FMF1WSFRF52-18K meets all critical electrical and mechanical parameters. While the substitute uses metal film composition instead of metal oxide film, and exhibits different temperature coefficient and maximum operating temperature specifications, these differences remain within acceptable substitution parameters for the defined resistance, tolerance, and power rating category. The substitute maintains active product status and full compliance with applicable regulations.

Parameter Comparison

Engineering Selection Recommendations

The FMF1WSFRF52-18K from YAGEO is a direct functional equivalent for the obsolete ROX1SF18K. Selection of this substitute is based on the following engineering criteria:

Electrical Compatibility: Both components provide identical resistance value (18 kOhms) and tolerance (±1%) at the same power rating (1W), ensuring equivalent electrical performance in circuit applications.

Mechanical Compatibility: Both components utilize axial through-hole packaging with two terminations, enabling direct physical substitution in existing PCB layouts and assembly processes.

Safety and Regulatory Compliance: Both components feature flame-proof construction and safety-rated design. The YAGEO substitute carries ROHS3 compliance and REACH unaffected status, meeting current regulatory requirements for new designs and manufacturing.

Product Availability: The YAGEO FMF1WSFRF52-18K maintains active product status with current inventory availability, providing long-term supply continuity compared to the obsolete TE Connectivity original.

Performance Characteristics: The substitute exhibits superior temperature coefficient performance (±100ppm/°C versus ±350ppm/°C) and extended maximum operating temperature (155°C versus 130°C), offering enhanced stability in temperature-sensitive applications.

Frequently Asked Questions (FAQ)

Q: Can the FMF1WSFRF52-18K directly replace the ROX1SF18K in existing designs?

A: Yes. Both components share identical electrical specifications (18 kOhms, ±1%, 1W) and axial through-hole packaging, enabling direct substitution without circuit redesign or PCB layout modification.

Q: What is the difference between metal oxide film and metal film composition?

A: Metal oxide film (ROX1SF18K) and metal film (FMF1WSFRF52-18K) are different resistive element technologies. Both achieve the specified 18 kOhms ±1% tolerance and 1W power rating. The metal film composition in the substitute provides lower temperature coefficient (±100ppm/°C) and higher maximum operating temperature (155°C).

Q: Are both components flame-proof and safety-rated?

A: Yes. Both the ROX1SF18K and FMF1WSFRF52-18K feature flame-proof construction and safety-rated design characteristics, meeting safety requirements for applications requiring these features.

Q: What is the significance of the ROHS3 and REACH compliance on the substitute?

A: ROHS3 compliance and REACH unaffected status indicate the FMF1WSFRF52-18K meets current European environmental and hazardous substance regulations. These certifications are required for new product designs and manufacturing in regulated markets.

Q: Are there physical size differences between the two components?

A: Minor dimensional differences exist. The ROX1SF18K measures 0.138" diameter × 0.394" length (3.50mm × 10.00mm), while the FMF1WSFRF52-18K measures 0.130" diameter × 0.354" length (3.30mm × 9.00mm). Both fit standard axial component footprints and spacing requirements.

Q: Which component should be selected for new designs?

A: The FMF1WSFRF52-18K should be selected for new designs. This component maintains active product status, provides regulatory compliance certifications, and ensures long-term supply availability compared to the obsolete ROX1SF18K.

Q: Is the substitute available in the same packaging format?

A: The FMF1WSFRF52-18K is supplied in Tape & Reel (TR) packaging, while the original ROX1SF18K packaging format is not specified in available data. Both formats are standard for through-hole axial resistors and are compatible with automated assembly processes.