Bottom Mount Switches | McMaster-Carr

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	Pipe Size Pipe Size

1/8

1/4

1/2

	For Use With For Use With

	Float Material Float Material

Plastic

Stainless Steel

Rubber

	Mounting Orientation Mounting Orientation

Vertical

	Input Voltage Input Voltage

120V AC

240V AC

	Mounting Location Mounting Location	Show

Bottom

	Mounting Location Mounting Location	Hide

	Switch Starting Position Switch Starting Position

1 Off (Normally Open)

1 On (Normally Closed)

	Stem Material Stem Material

Plastic

Stainless Steel

	Maximum Temperature Maximum Temperature

Less than 250° F

250° to 499° F

	System of Measurement System of Measurement

Inch

	Overall Diameter Overall Diameter

	Insertion Depth Insertion Depth

	Electrical Connection Type Electrical Connection Type

	Wire Leads

	Thread Type Thread Type

NPT

	Mount Type Mount Type

Bracket

Screw

Through Wall

	Connection Type Connection Type

	Pipe

	Current Current

	Maximum Pressure Maximum Pressure

	Float Height Float Height

	Industry Designation Industry Designation

SPST-NC

SPST-NO

	Minimum Specific Gravity Minimum Specific Gravity

	Number of Circuits Controlled Number of Circuits Controlled

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

RoHS Compliant

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

REACH Compliant

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44 Products

About Float Switches

Float Switch

Float Switch With Splash Guard

Mount these switches from outside the tank through a threaded connection. They activate process equipment such as pumps or motors when the diesel fuel, hydraulic fluid, or oil level in your tank reaches the float. Choose the switch with a stainless steel float for durability in harsh conditions.

Switches with splash guard minimize false switch activation caused by splashing liquid.

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

120V AC/240V AC Input Voltage
Pipe Size	Thread Type	Gender	Min. Specific Gravity	Max. Pressure	Temp. Range, °F	Insertion Dp.	Switch Starting Position	Industry Designation	Current	Mounting Location	Float Ht.	Overall Dia.	Electrical Connection		Each
Buna-N Rubber Float
1/8	NPT	Male	0.45	150 psi @ 70° F	35° to 250°	1 9/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.17 A @ 120 V AC	Top, Bottom	1"	1"	Wire Leads	00000000	000000
1/8	NPT	Male	0.55	150 psi @ 70° F	35° to 145°	1 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.28 A @ 120 V AC	Top, Bottom	1"	1"	Wire Leads	00000000	00000
1/4	NPT	Male	0.55	150 psi @ 70° F	35° to 145°	2 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	Top, Bottom	2"	1 1/4"	Wire Leads	00000000	00000
Buna-N Rubber Float with Splash Guard
1/8	NPT	Male	0.55	150 psi @ 70° F	35° to 145°	1 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.28 A @ 120 V AC	Top, Bottom	1"	1 1/2"	Wire Leads	00000000	00000
1/4	NPT	Male	0.55	150 psi @ 70° F	35° to 145°	2 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	Top, Bottom	2"	2"	Wire Leads	00000000	00000
316 Stainless Steel Float
1/8	NPT	Male	0.7	300 psi @ 70° F	35° to 300°	2 1/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	Top, Bottom	1 3/16"	1 1/8"	Wire Leads	0000000	000000

Vertical-Mount Float Switches with Bracket for Fuels and Oils

Use the included bracket to mount these switches to the inside of your tank. They activate process equipment such as pumps or motors when the diesel fuel, hydraulic fluid, or oil level in your tank reaches the float.

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

											Mounting
Min. Specific Gravity	Max. Pressure	Temp. Range, °F	Insertion Dp.	Switch Starting Position	Industry Designation	Current	Mounting Location	Float Ht.	Overall Dia.	Electrical Connection	Fasteners Included	No. of Holes	Hole Dia.		Each
120V AC/240V AC Input Voltage
Buna-N Rubber Float
0.55	150 psi @ 70° F	35° to 140°	3 3/16"	1 Off (Normally Open)	SPST-NO	0.17 A @ 120 V AC	Top, Bottom	1 9/16"	2 5/8"	Wire Leads	No	2	9/32"	0000000	0000000
0.55	150 psi @ 70° F	35° to 140°	3 3/16"	1 Off (Normally Open)	SPST-NO	0.4 A @ 120 V AC	Top, Bottom	1 9/16"	2 5/8"	Wire Leads	No	2	9/32"	0000000	000000
0.55	150 psi @ 70° F	35° to 140°	3 3/16"	1 On (Normally Closed)	SPST-NC	0.17 A @ 120 V AC	Top, Bottom	1 9/16"	2 5/8"	Wire Leads	No	2	9/32"	0000000	000000
0.55	150 psi @ 70° F	35° to 140°	3 3/16"	1 On (Normally Closed)	SPST-NC	0.4 A @ 120 V AC	Top, Bottom	1 9/16"	2 5/8"	Wire Leads	No	2	9/32"	0000000	000000

Through-Wall Vertical-Mount Float Switches for Water

Install these switches into an unthreaded hole at the top or bottom of your tank and secure with a nut from inside the tank. They activate process equipment such as pumps or motors when the water level in your tank reaches the float.

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

120V AC/240V AC Input Voltage
For Hole Dia.	Min. Specific Gravity	Max. Pressure	Temp. Range, °F	Insertion Dp.	Switch Starting Position	Industry Designation	Current	Float Ht.	Overall Dia.	Electrical Connection	Includes		Each
Polypropylene Plastic Float
3/8"	0.9	150 psi @ 70° F	35° to 150°	1 9/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.17 A @ 120 V AC	1"	1"	Wire Leads	Mounting Nut	00000000	000000

Vertical-Mount Float Switches for Water

With Buna-N Rubber Float

With Polypropylene And CPVC Float

With 316 Stainless Steel Float

Mount these switches from outside the tank through a threaded connection at the top or bottom of your tank. They activate process equipment such as pumps or motors when the water level in your tank reaches the float. Choose the switch with a stainless steel float for durability in harsh conditions.

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

120V AC/240V AC Input Voltage
Pipe Size	Thread Type	Gender	Min. Specific Gravity	Max. Pressure	Temp. Range, °F	Insertion Dp.	Switch Starting Position	Industry Designation	Current	Float Ht.	Overall Dia.	Electrical Connection		Each
Buna-N Rubber Float
1/8	NPT	Male	0.45	50 psi @ 70° F	35° to 150°	1 7/8"	1 On (Normally Closed)	SPST-NC	0.17 A @ 120 V AC	1 1/16"	1 7/8"	Wire Leads	00000000	000000
Polypropylene Plastic Float
1/8	NPT	Male	0.6	50 psi @ 70° F	35° to 225°	1 9/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.17 A @ 120 V AC	1"	1"	Wire Leads	00000000	00000
1/8	NPT	Male	0.9	150 psi @ 70° F	35° to 150°	1 9/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.17 A @ 120 V AC	1"	1"	Wire Leads	00000000	00000
1/8	NPT	Male	0.9	150 psi @ 70° F	35° to 150°	1 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.17 A @ 120 V AC	1"	3/4"	Wire Leads	00000000	00000
CPVC Plastic Float
1/4	NPT	Male	0.85	15 psi @ 70° F	35° to 180°	2 15/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.17 A @ 120 V AC	1 13/16"	1 1/2"	Wire Leads	0000000	000000
316 Stainless Steel Float
1/2	NPT	Male	0.35	300 psi @ 70° F	35° to 300°	4 13/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.83 A @ 120 V AC	3 1/2"	3 1/2"	Wire Leads	0000000	000000

Vertical-Mount Float Switches for Chemicals

Float Switch

Float Switch With Splash Guard

Mount these switches from outside the tank through a threaded connection at the top or bottom of your tank. They activate process equipment such as pumps or motors when the chemical level in your tank reaches the float. Choose the switch with a stainless steel float for durability in harsh conditions.

Switches with splash guard minimize false switch activation caused by splashing liquid.

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

120V AC/240V AC Input Voltage
Pipe Size	Thread Type	Gender	Min. Specific Gravity	Max. Pressure	Temp. Range, °F	Insertion Dp.	Switch Starting Position	Industry Designation	Current	Float Ht.	Overall Dia.	Electrical Connection		Each
Polypropylene Plastic Float
1/4	NPT	Male	0.85	100 psi @ 70° F	35° to 220°	2 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	2"	1 1/2"	Wire Leads	00000000	000000
1/4	NPT	Male	0.85	100 psi @ 70° F	35° to 220°	2 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	1 A @ 120 V AC	2"	1 1/2"	Wire Leads	00000000	00000
Polypropylene Plastic Float with Splash Guard
1/8	NPT	Male	0.9	100 psi @ 70° F	35° to 220°	1 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.3 A @ 120 V AC	1"	1 1/2"	Wire Leads	00000000	00000
1/4	NPT	Male	0.85	100 psi @ 70° F	35° to 220°	2 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	2"	2"	Wire Leads	00000000	00000
PVDF Plastic Float with Splash Guard
1/8	NPT	Male	0.95	15 psi @ 70° F	35° to 220°	1 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.3 A @ 120 V AC	1"	1 1/2"	Wire Leads	00000000	00000
316 Stainless Steel Float with Splash Guard
1/4	NPT	Male	0.65	200 psi @ 70° F	35° to 480°	2 15/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	2 1/8"	2 3/8"	Wire Leads	0000000	00000

Vertical-Mount Float Switches with Brackets for Chemicals

Use the included bracket to mount these switches to the inside of your tank. They activate process equipment such as pumps or motors when the chemical level in your tank reaches the float. A splash guard minimizes false switch activation caused by splashing liquid. Choose the switch with a stainless steel float for durability in harsh conditions.

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

120V AC/240V AC Input Voltage
Min. Specific Gravity	Max. Pressure	Temp. Range, °F	Insertion Dp.	Switch Starting Position	Industry Designation	Current	Float Ht.	Overall Dia.		Each
Polypropylene Plastic Float with Splash Guard
0.85	100 psi @ 70° F	35° to 220°	3 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	2"	2 1/2"	0000000	000000
316 Stainless Steel Float with Splash Guard
0.65	85 psi @ 70° F	35° to 230°	3 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	2"	2 1/2"	0000000	000000

Through-Wall Vertical-Mount Float Switches for Chemicals

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

120V AC Input Voltage
For Hole Dia.	Min. Specific Gravity	Max. Pressure	Temp. Range, °F	Insertion Dp.	Switch Starting Position	Industry Designation	Current	Float Ht.	Overall Dia.	Electrical Connection	Includes		Each
Polypropylene Plastic Float
3/8"	0.7	50 psi @ 70° F	35° to 220°	1 1/4"	1 Off (Normally Open)	SPST-NO	0.12 A @ 120 V AC	5/8"	9/16"	Wire Leads	Mounting Nut	00000000	000000
3/8"	0.7	50 psi @ 70° F	35° to 220°	1 1/4"	1 On (Normally Closed)	SPST-NC	0.12 A @ 120 V AC	5/8"	9/16"	Wire Leads	Mounting Nut	00000000	00000

Vertical-Mount Float Switches for Food and Beverage

Mount these switches into a threaded connection at the top or bottom of your tank. Often used in food-processing applications, they meet NSF/ANSI Standard 169.

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

Float Switches															Replacement Floats
	Pipe Size	Thread Type	Gender	Min. Specific Gravity	Max. Pressure	Temp. Range, °F	Insertion Dp.	Switch Starting Position	Industry Designation	Current	Float Ht.	O'all Dia.		Each		Each
120V AC/240V AC Input Voltage—Wire Leads
Polypropylene Plastic Float
A	1/8	NPT	Male	0.9	100 psi @ 70° F	35° to 220°	1 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.28 A @ 120 V AC	1"	1"	00000000	000000	00000000	000000
A	1/4	NPT	Male	0.87	100 psi @ 70° F	35° to 220°	2 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	2"	1 1/2"	00000000	00000	00000000	00000
PVDF Plastic Float
A	1/8	NPT	Male	0.85	15 psi @ 70° F	35° to 220°	1 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.28 A @ 120 V AC	1"	1"	00000000	00000	00000000	00000
316 Stainless Steel Float
B	1/8	NPT	Male	0.8	300 psi @ 70° F	35° to 390°	1 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.28 A @ 120 V AC	1 3/16"	1 1/8"	0000000	00000	0000000	00000
B	1/4	NPT	Male	0.65	200 psi @ 70° F	35° to 390°	2 15/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	2 1/8"	2 1/8"	0000000	00000	0000000	00000
B	1/4	NPT	Male	0.65	200 psi @ 70° F	35° to 480°	2 15/16"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.5 A @ 120 V AC	2 1/8"	2 1/8"	0000000	00000	0000000	00000
C	1/4	NPT	Male	0.8	500 psi @ 70° F	35° to 390°	2 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	1 A @ 120 V AC	2 1/16"	2 1/16"	0000000	00000	0000000	00000
C	1/4	NPT	Male	0.8	750 psi @ 70° F	35° to 300°	2 7/8"	1 Off (Normally Open)/1 On (Normally Closed)	SPST-NO SPST-NC	0.83 A @ 120 V AC	2 1/16"	2 1/16"	0000000	00000	0000000	00000

Replacement Clip for 1/4 Pipe Size Floats	0000000	Each	00000
Replacement Clip for 1/8 Pipe Size Polypropylene Plastic Floats	00000000	Each	0000
Replacement Clip for 1/8 Pipe Size 316 Stainless Steel Floats	0000000	Each	0000
Replacement Clip for PVDF Plastic Floats	00000000	Each	0000

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About Float Switches

Vertical-Mount Float Switches for Fuels and Oils

Vertical-Mount Float Switches with Bracket for Fuels and Oils

Through-Wall Vertical-Mount Float Switches for Water

Vertical-Mount Float Switches for Water

Vertical-Mount Float Switches for Chemicals

Vertical-Mount Float Switches with Brackets for Chemicals

Through-Wall Vertical-Mount Float Switches for Chemicals

Vertical-Mount Float Switches for Food and Beverage