Class J Fuses | McMaster-Carr

Clear All

	UL Class UL Class	Show

	UL Class UL Class	Hide

RK5

RK1

	Current Current

	Manufacturer Equivalent Manufacturer Equivalent

	Voltage Voltage

	Protection Type Protection Type

Time Delay

Fast Acting

	Overall Length Overall Length

	Fuse Type Fuse Type

	Cartridge

	Cartridge Fuse Style Cartridge Fuse Style

Ferrule

Knife Blade

	Blown Fuse Indicator Blown Fuse Indicator

Yes

	Breakthrough Current Breakthrough Current

	Number of Elements Number of Elements

	Specifications Met Specifications Met

CSA

	Overall Diameter Overall Diameter

	Rejection-Style End Rejection-Style End

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant

RoHS Compliant with
Exemptions

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	Indicator Type Indicator Type

Dot

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

	UL File Number UL File Number

E4273

Forward

How can we improve?

75 Products

Don’t see the fuse you need? Just tell us what you’re looking for and we’ll get it for you.

About Fuses

Ferrule Style

Knife-Blade Style

Ferrule Style with Blown-Fuse Indicator

Knife-Blade Style with Blown-Fuse Indicator

Also known as dual-element fuses, these fuses withstand current overload for a short time so they won't open when exposed to harmless temporary surges, such as when starting a motor. More compact than UL Class RK1 or RK5 fuses, they are suitable for tight spaces. Use with Fuse Blocks for UL Class J Fuses.

Breakthrough current, labeled on the fuse as IR, is the maximum current that a fuse can safely stop in the event of a short circuit.

Fuses with blown fuse indicator have a dot on the side that changes color when the fuse blows.

For technical drawings and 3-D models, click on a part number.

			Overall							Each
Current, A	Voltage	Breakthrough Current	Lg.	Dia.	No. of Elements	Cartridge Fuse Style	Blown Fuse Indicator	Specifications Met		1-9	10-Up
Manufacturer Equivalent: AJT, JTD, LPJ-SP
1	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	000000	000000
1 1/4	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
2	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
2 1/2	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
2 8/10	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
3	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
4	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
5	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
6	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
7	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
8	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
10	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
12	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
15	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
20	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
25	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
30	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 1/4"	13/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
35	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 3/8"	1 1/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
40	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 3/8"	1 1/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
45	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 3/8"	1 1/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
50	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 3/8"	1 1/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
60	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	2 3/8"	1 1/16"	2	Ferrule	No	UL Listed, CSA Certified	000000000	00000	00000
70	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	4 5/8"	1 1/8"	2	Knife Blade	No	UL Listed, CSA Certified	000000000	000000	00000
80	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	4 5/8"	1 1/8"	2	Knife Blade	No	UL Listed, CSA Certified	000000000	000000	00000
90	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	4 5/8"	1 1/8"	2	Knife Blade	No	UL Listed, CSA Certified	000000000	000000	00000
100	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	4 5/8"	1 1/8"	2	Knife Blade	No	UL Listed, CSA Certified	000000000	000000	00000
125	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	5 3/4"	1 5/8"	2	Knife Blade	No	UL Listed, CSA Certified	000000000	000000	000000
150	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	5 3/4"	1 5/8"	2	Knife Blade	No	UL Listed, CSA Certified	000000000	000000	000000
175	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	5 3/4"	1 5/8"	2	Knife Blade	No	UL Listed, CSA Certified	000000000	000000	000000
200	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	5 3/4"	1 5/8"	2	Knife Blade	No	UL Listed, CSA Certified	00000000	000000	000000
250	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	7 1/8"	2 1/8"	2	Knife Blade	No	UL Listed, CSA Certified	000000000	000000	000000
400	600V AC/300V DC	100,000 A @ 300 V DC 300,000 A @ 600 V AC	7 1/8"	2 1/8"	2	Knife Blade	No	UL Listed, CSA Certified	00000000	000000	000000
Manufacturer Equivalent: AJT, JTD-ID, LPJ-SPI
8	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
9	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
10	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
12	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
15	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
17 1/2	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
20	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
25	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
30	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
35	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 3/8"	1 1/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
40	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 3/8"	1 1/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
45	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 3/8"	1 1/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
50	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 3/8"	1 1/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
60	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	2 3/8"	1 1/16"	1	Ferrule	Yes	UL Listed, CSA Certified	0000000	00000	00000
70	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	4 5/8"	1 1/16"	2	Knife Blade	Yes	UL Listed, CSA Certified	0000000	00000	00000
80	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	4 5/8"	1 1/16"	2	Knife Blade	Yes	UL Listed, CSA Certified	0000000	00000	00000
90	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	4 5/8"	1 1/16"	2	Knife Blade	Yes	UL Listed, CSA Certified	0000000	00000	00000
100	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	4 5/8"	1 1/16"	2	Knife Blade	Yes	UL Listed, CSA Certified	0000000	00000	00000
125	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	5 3/4"	1 5/8"	4	Knife Blade	Yes	UL Listed, CSA Certified	0000000	000000	000000
150	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	5 3/4"	1 5/8"	4	Knife Blade	Yes	UL Listed, CSA Certified	0000000	000000	000000
175	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	5 3/4"	1 5/8"	4	Knife Blade	Yes	UL Listed, CSA Certified	0000000	000000	000000
200	600V AC/500V DC	100,000 A @ 500 V DC 200,000 A @ 600 V AC	5 3/4"	1 5/8"	4	Knife Blade	Yes	UL Listed, CSA Certified	0000000	000000	000000

UL Class J Fast-Acting Fuses for Tight Spaces

Ferrule Style

Knife-Blade Style

These fuses open circuits quickly when surges are detected. More compact than UL Class RK1 or RK5 fuses, they are suitable for tight spaces. Use with Fuse Blocks for UL Class J Fuses.

Breakthrough current, labeled on the fuse as IR, is the maximum current that a fuse can safely stop in the event of a short circuit.

For technical drawings and 3-D models, click on a part number.

			Overall						Each
Current, A	Voltage	Breakthrough Current	Lg.	Dia.	No. of Elements	Cartridge Fuse Style	Specifications Met		1-9	10-Up
Manufacturer Equivalent: A4J, JKS, JLS
1	600V AC	200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	000000	000000
3	600V AC	200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
4	600V AC	200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
5	600V AC	200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
6	600V AC	200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
8	600V AC	200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
10	600V AC	200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
12	600V AC	200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
15	600V AC/200V DC	10,000 A @ 200 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
20	600V AC/200V DC	10,000 A @ 200 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
25	600V AC/200V DC	10,000 A @ 200 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
30	600V AC/200V DC	10,000 A @ 200 V DC 200,000 A @ 600 V AC	2 1/4"	13/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
35	600V AC	200,000 A @ 600 V AC	2 13/32"	1 1/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
40	600V AC/175V DC	10,000 A @ 175 V DC 200,000 A @ 600 V AC	2 3/8"	1 1/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
45	600V AC	200,000 A @ 600 V AC	2 13/32"	1 1/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
50	600V AC/175V DC	10,000 A @ 175 V DC 200,000 A @ 600 V AC	2 3/8"	1 1/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
60	600V AC/175V DC	10,000 A @ 175 V DC 200,000 A @ 600 V AC	2 3/8"	1 1/16"	1	Ferrule	UL Listed, CSA Certified	00000000	00000	00000
80	600V AC	200,000 A @ 600 V AC	4 5/8"	1 1/8"	1	Knife Blade	UL Listed, CSA Certified	00000000	00000	00000
100	600V AC	200,000 A @ 600 V AC	4 5/8"	1 1/8"	1	Knife Blade	UL Listed, CSA Certified	00000000	00000	00000
200	600V AC	200,000 A @ 600 V AC	5 3/4"	1 5/8"	1	Knife Blade	UL Listed, CSA Certified	0000000	000000	000000
400	600V AC	200,000 A @ 600 V AC	7 1/8"	2 1/8"	1	Knife Blade	UL Listed, CSA Certified	0000000	000000	000000

Email Us

About Fuses

UL Class J Time-Delay Fuses for Tight Spaces

UL Class J Fast-Acting Fuses for Tight Spaces