Bourns 3386F-1-503 50kΩ Trimmer Potentiometer Equivalent & Substitute Parts

Part Overview

The Bourns 3386F-1-503 is a 50 kΩ, 0.5W through-hole trimmer potentiometer with cermet resistive material, top adjustment, and PC pin termination. This sealed Trimpot® 3386 series component is actively produced and widely used in precision circuit tuning applications. Equivalent and substitute parts are identified based on matching electrical specifications, mechanical compatibility, and functional performance within the allowed parameter tolerances for this product category.

Key Parameters

Parameter	Value
Resistance	50 kΩ
Power Rating	0.5W (1/2W)
Tolerance	±10%
Temperature Coefficient	±100 ppm/°C
Number of Turns	1
Adjustment Type	Top Adjustment
Resistive Material	Cermet
Mounting Type	Through Hole
Termination Style	PC Pins
Size	Square - 0.375" x 0.375" (9.53mm x 9.53mm)

Substitute Part Grouping Explanation

Substitution eligibility is determined by matching the following critical parameters: resistance value (50 kΩ), power rating (0.5W), tolerance (±10%), temperature coefficient (±100 ppm/°C), number of turns (1), resistive material (cermet), mounting type (through hole), and termination style (PC pins). Substitute parts are grouped into two categories:

Direct Equivalents: Parts with identical electrical specifications and compatible mechanical dimensions that support direct replacement without circuit modification.

Functional Equivalents: Parts with identical electrical specifications but differing in adjustment type (side vs. top) or physical dimensions, requiring mechanical accommodation or board layout adjustment.

Parameter Comparison

Part Number	Manufacturer	Resistance	Power (W)	Tolerance	Temp Coeff (ppm/°C)	Turns	Adjustment	Material	Size (Face)	RoHS Status	Packaging
3386F-1-503	Bourns Inc.	50 kΩ	0.5	±10%	±100	1	Top	Cermet	0.375" x 0.375" (9.53mm)	Non-compliant	Tube
3386F-1-503LF	Bourns Inc.	50 kΩ	0.5	±10%	±100	1	Top	Cermet	0.375" x 0.375" (9.53mm)	ROHS3 Compliant	Tube
25PR50KLF	TT Electronics/BI	50 kΩ	0.5	±10%	±100	1	Top	Cermet	0.270" x 0.270" (6.86mm)	RoHS Compliant	Tube
72PR50KLF	TT Electronics/BI	50 kΩ	0.5	±10%	±100	1	Top	Cermet	0.375" x 0.375" (9.53mm)	ROHS3 Compliant	Bulk
82PR50KLF	TT Electronics/BI	50 kΩ	0.5	±10%	±100	1	Top	Cermet	0.250" Dia (6.35mm)	ROHS3 Compliant	Bulk
M63P503KB40	Vishay Spectrol	50 kΩ	0.5	±10%	±100	1	Side	Cermet	0.395" x 0.395" (10.03mm)	ROHS3 Compliant	Bulk

Engineering Selection Recommendations

3386F-1-503LF (Bourns Inc.): Direct equivalent with identical electrical and mechanical specifications. ROHS3 compliant status provides regulatory advantage over the original 3386F-1-503. Recommended for new designs and RoHS-regulated applications.

72PR50KLF (TT Electronics/BI): Functionally equivalent with matching face dimensions (0.375" x 0.375"), electrical specifications, and ROHS3 compliance. Bulk packaging available. Suitable for high-volume production environments.

25PR50KLF (TT Electronics/BI): Electrically equivalent with reduced physical footprint (0.270" x 0.270" face). RoHS compliant. Requires PCB layout modification due to smaller dimensions. Applicable where space constraints exist.

82PR50KLF (TT Electronics/BI): Electrically equivalent with circular form factor (0.250" diameter). ROHS3 compliant. Requires mechanical accommodation for round package geometry. Suitable for applications with circular mounting provisions.

M63P503KB40 (Vishay Spectrol): Electrically equivalent with side adjustment instead of top adjustment. ROHS3 compliant. Requires board layout modification to accommodate side-mounted adjustment screw. Applicable only where side adjustment access is available.

Frequently Asked Questions (FAQ)

Q: Can 3386F-1-503LF replace 3386F-1-503 directly? A: Yes. Both parts share identical electrical specifications (50 kΩ, 0.5W, ±10% tolerance, ±100 ppm/°C), adjustment type (top), and mechanical dimensions (0.375" x 0.375" square). The primary difference is RoHS compliance status. Direct PCB substitution is supported.

Q: What is the difference between top adjustment and side adjustment models? A: Top adjustment models (3386F-1-503, 72PR50KLF, 25PR50KLF, 82PR50KLF) feature a trimmer screw accessible from the top surface. Side adjustment models (M63P503KB40) feature the trimmer screw on the side. Board layout and access requirements differ. Top adjustment is standard for most applications.

Q: Are there physical size differences between substitute parts? A: Yes. The 3386F-1-503 and 72PR50KLF share 0.375" x 0.375" square dimensions. The 25PR50KLF is smaller (0.270" x 0.270" square). The 82PR50KLF is circular (0.250" diameter). The M63P503KB40 is larger (0.395" x 0.395" square). PCB footprint verification is required for non-identical dimensions.

Q: Which substitute parts are RoHS compliant? A: 3386F-1-503LF, 25PR50KLF, 72PR50KLF, 82PR50KLF, and M63P503KB40 are all RoHS compliant. The original 3386F-1-503 is RoHS non-compliant. For regulated applications, use compliant alternatives.

Q: What packaging options are available? A: 3386F-1-503 and 3386F-1-503LF are supplied in tube packaging. 25PR50KLF is supplied in tube packaging. 72PR50KLF, 82PR50KLF, and M63P503KB40 are supplied in bulk packaging. Packaging selection affects inventory management and component handling.

Q: Can I use 25PR50KLF or 82PR50KLF if my PCB is designed for the standard 0.375" x 0.375" footprint? A: No. The 25PR50KLF (0.270" x 0.270" square) and 82PR50KLF (0.250" diameter) have different physical dimensions and will not fit standard 0.375" x 0.375" footprints. PCB redesign is required for these alternatives.

Q: Are all substitute parts rated for the same power dissipation? A: Yes. All listed substitute parts are rated at 0.5W (1/2W) power dissipation with ±10% tolerance and ±100 ppm/°C temperature coefficient. Electrical performance is equivalent across all alternatives.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message