Mil. Spec. Caps | McMaster-Carr

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61 Products

Conductive Caps

Shield electrical connectors from interference and static while keeping out dust. These caps have a surface resistivity of less than 10⁵ ohms/sq. to block stray signals and dissipate static charges much more quickly than antistatic caps. They protect threaded and unthreaded connectors during shipping and storage.

Polyethylene—These tough caps are hard and wear resistant to hold up against scrapes and gouges.

	For Thread Size	Inside Ht.	Flexibility	Max. Temp., ° F	Max. Surface Resistivity, ohm/sq.	Color	Mil. Spec.	Pkg. Qty.		Pkg.
Polyethylene



	0.244"	1/4"-28	15/32"	Rigid	140	1× 10^5	Black	MIL-PRF-81705	50	94075K11	000000
	0.368"	3/8"-24	1/2"	Rigid	140	1× 10^5	Black	MIL-PRF-81705	50	94075K12	00000
	0.487"	1/2"-28	1/2"	Rigid	140	1× 10^5	Black	MIL-PRF-81705	50	94075K13	00000
	0.607"	5/8"-24	1/2"	Rigid	140	1× 10^5	Black	MIL-PRF-81705	50	94075K14	00000
	0.73"	3/4"-20	1/2"	Rigid	140	1× 10^5	Black	MIL-PRF-81705	25	94075K15	00000
	0.852"	7/8"-20	1/2"	Rigid	140	1× 10^5	Black	MIL-PRF-81705	25	94075K16	00000
	0.992"	1"-20	1/2"	Rigid	140	1× 10^5	Black	MIL-PRF-81705	25	94075K17	00000
	1.244"	1 1/4"-18	9/16"	Rigid	140	1× 10^5	Black	MIL-PRF-81705	25	94075K18	00000
	1.478"	1 1/2"-18	9/16"	Rigid	140	1× 10^5	Black	MIL-PRF-81705	25	94075K19	00000

Screw-In Plugs for Pipe and Tubing

Threaded for the most secure fit on female pipe and fittings. These plugs protect from damage during shipping and storage. They also keep dust, paint, and coatings from blocking holes and threads.

For Tapered-Thread Fittings

Image of Product. Front orientation. Contains Annotated. Protective Plugs. Screw In, For Round Holes, For Pipe, For Round Shapes, For Tapered-Thread Fittings , External Square Drive.

External Square

Drive

External 12-Point

Drive

Polyethylene—A balance of wear and chemical resistance for use in a variety of environments. These plugs withstand scratches and scrapes as well as mild acids, solvents, and chemical cleaners.

	Max. Temp., ° F	Color	Pkg. Qty.		Pkg.
External Square Drive





	Polyethylene

	1/8	NPT	7/16"	160	Red	100	5481K14	00000
	1/4	NPT	1/2"	160	Red	100	5481K15	00000
	3/8	NPT	1/2"	160	Red	100	5481K16	00000
	1/2	NPT	19/32"	160	Red	100	5481K17	00000
	3/4	NPT	5/8"	160	Red	50	5481K18	00000
	1	NPT	23/32"	160	Red	25	5481K19	00000
	1 1/4	NPT	3/4"	160	Red	25	5481K21	00000
	1 1/2	NPT	31/32"	160	Red	10	5481K22	00000


	External 12-Point Drive





					Polyethylene

					1/8	NPT	9/32"	160	Red	100	6844K29	00000
					1/4	NPT	3/8"	160	Red	100	6844K31	00000
					3/8	NPT	11/32"	160	Red	100	6844K32	00000
					1/2	NPT	9/16"	160	Red	100	6844K33	00000
					3/4	NPT	5/8"	160	Red	50	6844K34	00000

Antistatic Plugs

Protect sensitive electronics with plugs that prevent static buildup and keep dust out of connections. They have a surface resistivity of less than 10¹² ohms/sq. for packaging and storing components such as semiconductors and resistors. Plugs fit threaded and unthreaded electrical connectors.

Polyethylene—Hard and wear resistant to hold up against scrapes and gouges.

	For Thread Size	Ht.	Head Dia.	Max. Surface Resistivity, ohm/sq.	Max. Temp., ° F	Color	Mil. Spec.	Pkg. Qty.		Pkg.
Polyethylene



	15/32"	1/2"-28	5/8"	11/16"	1× 10^12	140	Pink	MIL-PRF-81705	100	94075K71	000000
	19/32"	5/8"-24	5/8"	3/4"	1× 10^12	140	Pink	MIL-PRF-81705	100	94075K72	00000
	23/32"	3/4"-20	5/8"	7/8"	1× 10^12	140	Pink	MIL-PRF-81705	100	94075K73	00000
	27/32"	7/8"-20	5/8"	1 1/16"	1× 10^12	140	Pink	MIL-PRF-81705	50	94075K74	00000
	29/32"	1"-20	5/8"	1 1/8"	1× 10^12	140	Pink	MIL-PRF-81705	50	94075K75	00000
	1 1/32"	1 1/8"-18	5/8"	1 1/4"	1× 10^12	140	Pink	MIL-PRF-81705	50	94075K76	00000
	1 5/32"	1 1/4"-18	5/8"	1 7/16"	1× 10^12	140	Pink	MIL-PRF-81705	50	94075K77	00000
	1 15/32"	1 1/2"-18	5/8"	1 11/16"	1× 10^12	140	Pink	MIL-PRF-81705	50	94075K79	00000
	1 31/32"	2"-18	5/8"	2 5/32"	1× 10^12	140	Pink	MIL-PRF-81705	25	94075K82	00000

Antistatic Caps

Protect sensitive electronics with caps that prevent static buildup and keep dust out of connections. They have a surface resistivity of less than 10¹² ohms/sq. for packaging and storing components such as semiconductors and resistors. Caps fit threaded and unthreaded electrical connectors.

Polyethylene—These tough caps are hard and wear resistant to hold up against scrapes and gouges.

	For Thread Size	Inside Ht.	Flexibility	Max. Temp., ° F	Max. Surface Resistivity, ohm/sq.	Color	Mil. Spec.	Pkg. Qty.		Pkg.
Polyethylene



	0.245"	1/4"-28	1/2"	Rigid	140	1× 10^12	Pink	MIL-PRF-81705	100	94075K31	000000
	0.36"	3/8"-24	1/2"	Rigid	140	1× 10^12	Pink	MIL-PRF-81705	100	94075K32	00000
	0.48"	1/2"-28	1/2"	Rigid	140	1× 10^12	Pink	MIL-PRF-81705	100	94075K33	00000
	0.6"	5/8"-24	1/2"	Rigid	140	1× 10^12	Pink	MIL-PRF-81705	100	94075K34	00000
	0.72"	3/4"-20	1/2"	Rigid	140	1× 10^12	Pink	MIL-PRF-81705	100	94075K35	00000
	0.85"	7/8"-20	1/2"	Rigid	140	1× 10^12	Pink	MIL-PRF-81705	50	94075K36	00000
	0.973"	1"-20	1/2"	Rigid	140	1× 10^12	Pink	MIL-PRF-81705	50	94075K37	00000
	1.231"	1 1/4"-18	9/16"	Rigid	140	1× 10^12	Pink	MIL-PRF-81705	50	94075K38	00000
	1.463"	1 1/2"-18	9/16"	Rigid	140	1× 10^12	Pink	MIL-PRF-81705	50	94075K39	00000

Conductive Plugs

Shield electrical connectors from interference and static while keeping out dust. These plugs have a surface resistivity of less than 10⁵ ohms/sq. to block stray signals from nearby equipment. They also dissipate static charges much more quickly than antistatic plugs. Use them to protect threaded and unthreaded connectors during shipping and storage.

Polyethylene—Hard and wear resistant to hold up against scrapes and gouges.

	For Thread Size	Ht.	Head Dia.	Max. Surface Resistivity, ohm/sq.	Max. Temp., ° F	Color	Mil. Spec.	Pkg. Qty.		Pkg.
Polyethylene



	15/32"	1/2"-28	5/8"	11/16"	1× 10^5	140	Black	MIL-PRF-81705	50	94075K51	000000
	19/32"	5/8"-24	5/8"	3/4"	1× 10^5	140	Black	MIL-PRF-81705	50	94075K52	00000
	23/32"	3/4"-20	5/8"	7/8"	1× 10^5	140	Black	MIL-PRF-81705	50	94075K53	00000
	27/32"	7/8"-20	5/8"	1 1/16"	1× 10^5	140	Black	MIL-PRF-81705	50	94075K54	00000
	31/32"	1"-20	5/8"	1 3/16"	1× 10^5	140	Black	MIL-PRF-81705	50	94075K55	00000
	1 3/32"	1 1/8"-18	5/8"	1 1/4"	1× 10^5	140	Black	MIL-PRF-81705	25	94075K56	00000
	1 7/32"	1 1/4"-18	5/8"	1 1/2"	1× 10^5	140	Black	MIL-PRF-81705	25	94075K57	00000
	1 11/32"	1 3/8"-18	5/8"	1 17/32"	1× 10^5	140	Black	MIL-PRF-81705	10	94075K88	0000
	1 15/32"	1 1/2"-18	5/8"	1 11/16"	1× 10^5	140	Black	MIL-PRF-81705	25	94075K59	00000
	1 31/32"	2"-18	5/8"	2 5/32"	1× 10^5	140	Black	MIL-PRF-81705	10	94075K62	00000

Screw-On Caps

Aluminum

Thread onto male pipe and fittings for the most secure fit. These caps keep dust, paint, and coatings out of threads and pipe. They also protect from damage during manufacturing, shipping, and storage.

Aluminum—Use aluminum caps instead of steel to prevent corrosion from spreading to aluminum pipe and tubing.

	Thread
	Size	Type	For OD	Inside Ht.	Flexibility	Max. Temp., ° F	Mil. Spec.	Pkg. Qty.		Pkg.
Aluminum





				For Straight-Thread Fittings

				5/16"-24	UNF	5/16"	21/64"	Rigid	650	MIL-C-5501/3	50	3522T11	000000
				3/8"-24	UNF	3/8"	19/64"	Rigid	650	MIL-C-5501/3	50	3522T12	00000
				7/16"-20	UNF	7/16"	15/32"	Rigid	650	MIL-C-5501/3	50	3522T13	0000
				1/2"-20	UNF	1/2"	7/16"	Rigid	650	MIL-C-5501/3	50	3522T14	00000
				9/16"-18	UNF	9/16"	15/32"	Rigid	650	MIL-C-5501/3	50	3522T15	00000
				5/8"-18	UNF	5/8"	33/64"	Rigid	650	MIL-C-5501/3	50	3522T16	00000
				3/4"-16	UNF	3/4"	35/64"	Rigid	650	MIL-C-5501/3	50	3522T17	00000
				7/8"-14	UNF	7/8"	21/32"	Rigid	650	MIL-C-5501/3	50	3522T18	00000
				1 1/16"-12	UN	1 1/16"	49/64"	Rigid	650	MIL-C-5501/3	25	3522T19	00000
				1 5/16"-12	UN	1 5/16"	49/64"	Rigid	650	MIL-C-5501/3	25	3522T21	00000


				1 5/8"-12	UN	1 5/8"	23/32"	Rigid	650	MIL-C-5501/3	10	3522T22	00000