Verre & Ceramic 5×20 Fuse Tube Made in China

There is quite a lot of information about 5*20 fast-acting and slow-acting axial Fuse with Lead. This is a cylindrical glass or ceramic tubular fuse with a diameter of 5mm and a length of 20mm: the rated current ranges from 0.1A to 30A, and the rated voltage is commonly 250V/125V.

Note that the user may be an electronic engineer or maintenance personnel, and needs to distinguish between fast and slow-acting types. The letter identification rule in the product model: F stands for fast-acting and T stands for slow-acting. Par exemple, F1A250V is a fast-acting type with a rated current of 1A. This information is crucial for correct selection, especially the slow-acting type is suitable for motor loads.

In terms of safety certification, this type of fuse usually has CCC, UL and other certifications. Users need to pay special attention if they are designing export products. There are two main forms of installation: with lead pins and fuse holders. Outdoor waterproof types require special waterproof fuse holders.

Price factors cannot be ignored. When purchasing in bulk, the price of a single piece may be as low as $0.02, but fuse holders with waterproof functions will be more expensive. If the user is purchasing in bulk, this information may be important.

The following is a summary of the core information about ‌5×20mm fuses‌, including specifications, genres, selection points and application scenarios:
🔧 ‌I. Basic specifications‌

Parameters ‌‌	‌Description‌‌
‌‌Size‌‌	Diameter 5mm × Length 20mm (standard cylindrical)
‌‌Rated voltage‌‌	Mainstream is ‌250V‌ (partially supports higher voltage)
‌‌Rated current‌‌	Covering ‌0.1A–30A‌ (such as 0.5A, 1UN, 3UN, 5UN, 10UN, 20UN, etc.)
‌Material type‌ ‌‌	‌Glass tube‌ (transparent and easy to observe the melting state) / ‌Ceramic tube‌ (higher withstand voltage and breaking capacity)

II. Distinguishing between fast-break and slow-break types‌

Type‌	‌Mark ‌ ‌‌	‌Features ‌ ‌‌	Typical application scenarios ‌
‌Fast break (F) ‌	`F`	Millisecond-level fuse when overcurrent occurs, extremely fast response	Charge résistive (équipement de chauffage électrique), IC protection circuit, no surge scenario
Slow break (T) ‌	`T`	Withstands short-term pulse current (such as startup surge), and only fuses when overloaded continuously	Moteur, switching power supply, capacitive/inductive load (compressor, charging circuit)

‌💡 ‌Example model‌:
Fast-break: F1A250V 5×20 (1A/250V fast-break)
Slow-break: T3.15A250V 5×20 (3.15A/250V slow-break)

⚠️ ‌III. Key points for selection‌

‌Current matching‌:
Rated current ≥ circuit maximum operating current × ‌1.5–2 times‌ (surge compatible);
Motor loads must be slow-break type (T) to avoid false fuses during startup.
‌Voltage matching‌:
The rated voltage of the fuse must be ‌≥ the maximum voltage of the circuit‌.
‌Certification mark‌:
Safety certifications such as ‌CCC, UL, and VDE‌ must be passed (product labeling or packaging instructions).

🔌 ‌IV. installation and accessories‌
‌Pin type‌:
Pin with lead (direct welding)
No lead (need to be used with fuse holder)
‌Fuse holder‌:
Waterproof type (such as H3-520E, suitable for outdoor equipment)
Standard socket type (such as ST 4-HESI, industrial terminal block)

💎V. brand and price reference‌

Brand‌‌	‌‌Features‌ ‌‌	Unit price range‌
Littelfuse	High reliability industrial grade	$0.08+/PC (slow break)
Betterfuse	Special for ceramic tubes (home appliances/PC power supply)	Customized quotation
Domestic general type	Economic glass fuse tube (électronique grand public)	$0.02~$0.1/PCS

⚠️ ‌Risk of wrong replacement‌:
‌Disable fast break to replace slow break‌ (such as motor circuit), otherwise the startup surge will cause the fuse to blow;
When replacing, the current, voltage and fuse type must be strictly matched.