Mil. Spec. Caps | McMaster-Carr

	Plug Type Plug Type


Push In	Screw In

	For Thread Diameter For Thread Diameter

	Material Material

Plastic

Aluminum

	For ID For ID

	For Surface Type For Surface Type

Threaded

Unthreaded

	Color Color

	Black
	Pink
	Red

	Head Diameter Head Diameter

	For OD For OD

	Pipe Size Pipe Size

	Drive Style Drive Style


External Square	External 12- Point

	Cap Type Cap Type


Push On	Screw On

	For Connection Type For Connection Type

Straight-Thread Pipe

Tapered-Thread Pipe

	Electrical Properties Electrical Properties

Conductive

Antistatic

	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

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

DFARS Specialty Metals
COTS-Exempt

	Maximum Temperature Maximum Temperature

140° F

160° F

650° F

	Specifications Met Specifications Met

MIL-PRF-81705

MIL-C-5501/3

	Height Height

	Maximum Surface Resistivity Maximum Surface Resistivity

10⁵ ohms/sq

10¹² ohms/sq

	Hardness Hardness

Durometer 60A

Durometer 45D

Durometer 65D

	Inside Height Inside Height

	Thread Size Thread Size

61 Products

Conductive Round Plugs

With a surface resistivity of less than 10⁵ ohms/sq, these plugs not only dissipate electrical charges, but can be used as an electrical shield. All meet the static requirements of MIL-PRF-81705. They fit electrical connectors with straight threads as well as unthreaded bayonet-type connectors.

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

Polyethylene Plastic
For ID	For Thread Dia.	Ht.	Head Dia.	Max. Surface Resistivity	Max. Temp., °F	Hardness	Color	Specifications Met	Pkg. Qty.		Pkg.
15/32"	1/2"	5/8"	11/16"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	000000
19/32"	5/8"	5/8"	3/4"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	00000
23/32"	3/4"	5/8"	7/8"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	00000
27/32"	7/8"	5/8"	1 1/16"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	00000
31/32"	1"	5/8"	1 3/16"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	00000
1 3/32"	1 1/8"	5/8"	1 1/4"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	25	00000000	00000
1 7/32"	1 1/4"	5/8"	1 1/2"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	25	00000000	00000
1 11/32"	1 3/8"	5/8"	1 17/32"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	10	00000000	0000
1 15/32"	1 1/2"	5/8"	1 11/16"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	25	00000000	00000
1 31/32"	2"	5/8"	2 5/32"	10⁵ ohms/sq	140°	Durometer 45D	Black	MIL-PRF-81705	10	00000000	00000

Antistatic Round Plugs

Keep equipment safe from electrical currents with these plugs that have a surface resistivity of less than 10¹² ohms/sq. All meet the static requirements of MIL-PRF-81705. They fit electrical connectors with straight threads as well as unthreaded bayonet-type connectors.

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

Polyethylene Plastic
For ID	For Thread Dia.	Ht.	Head Dia.	Max. Surface Resistivity	Max. Temp., °F	Hardness	Color	Specifications Met	Pkg. Qty.		Pkg.
15/32"	1/2"	5/8"	11/16"	10¹² ohms/sq	140°	Durometer 60A	Pink	MIL-PRF-81705	100	00000000	000000
19/32"	5/8"	5/8"	3/4"	10¹² ohms/sq	140°	Durometer 60A	Pink	MIL-PRF-81705	100	00000000	00000
21/32"	3/4"	5/8"	7/8"	10¹² ohms/sq	140°	Durometer 60A	Pink	MIL-PRF-81705	100	00000000	00000
27/32"	7/8"	5/8"	1 1/16"	10¹² ohms/sq	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
29/32"	1"	5/8"	1 1/8"	10¹² ohms/sq	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
1 1/32"	1 1/8"	5/8"	1 1/4"	10¹² ohms/sq	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
1 5/32"	1 1/4"	5/8"	1 7/16"	10¹² ohms/sq	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
1 15/32"	1 1/2"	5/8"	1 11/16"	10¹² ohms/sq	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
1 31/32"	2"	5/8"	2 5/32"	10¹² ohms/sq	140°	Durometer 60A	Pink	MIL-PRF-81705	25	00000000	00000

Threaded Round Plugs for NPT Pipe

External Square Drive

External 12-Point Drive

Protect internally threaded NPT connections from contaminants during fabrication and storage.

Install external square-drive plugs manually or with a square-drive wrench or socket.

Install external 12-point drive plugs manually or with a 12-point wrench or socket.

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

External Square Drive
Pipe Size	Ht.	Max. Temp., °F	Hardness	Color	Pkg. Qty.		Pkg.
Polyethylene Plastic
1/8	7/16"	160°	Durometer 65D	Red	100	0000000	00000
1/4	1/2"	160°	Durometer 65D	Red	100	0000000	00000
3/8	1/2"	160°	Durometer 65D	Red	100	0000000	00000
1/2	19/32"	160°	Durometer 65D	Red	100	0000000	00000
3/4	5/8"	160°	Durometer 65D	Red	50	0000000	00000
1	23/32"	160°	Durometer 65D	Red	25	0000000	00000
1 1/4	3/4"	160°	Durometer 65D	Red	25	0000000	00000
1 1/2	31/32"	160°	Durometer 65D	Red	10	0000000	00000
External 12-Point Drive
Polyethylene Plastic
1/8	9/32"	160°	Durometer 65D	Red	100	0000000	00000
1/4	3/8"	160°	Durometer 65D	Red	100	0000000	00000
3/8	11/32"	160°	Durometer 65D	Red	100	0000000	00000
1/2	9/16"	160°	Durometer 65D	Red	100	0000000	00000
3/4	5/8"	160°	Durometer 65D	Red	50	0000000	00000

Antistatic Round Caps

Keep equipment safe from electrical currents with these caps that have a surface resistivity of less than 10¹² ohms/sq. All meet the static requirements of MIL-PRF-81705. They fit electrical connectors with straight threads as well as unthreaded bayonet-type connectors.

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

Rigid Plastic
For OD	For Thread Dia.	Inside Ht.	Max. Temp., °F	Max. Surface Resistivity	Color	Specifications Met	Pkg. Qty.		Pkg.
0.245"	1/4"	1/2"	140°	10¹² ohms/sq	Pink	MIL-PRF-81705	100	00000000	000000
0.36"	3/8"	1/2"	140°	10¹² ohms/sq	Pink	MIL-PRF-81705	100	00000000	00000
0.48"	1/2"	1/2"	140°	10¹² ohms/sq	Pink	MIL-PRF-81705	100	00000000	00000
0.6"	5/8"	1/2"	140°	10¹² ohms/sq	Pink	MIL-PRF-81705	100	00000000	00000
0.72"	3/4"	1/2"	140°	10¹² ohms/sq	Pink	MIL-PRF-81705	100	00000000	00000
0.85"	7/8"	1/2"	140°	10¹² ohms/sq	Pink	MIL-PRF-81705	50	00000000	00000
0.973"	1"	1/2"	140°	10¹² ohms/sq	Pink	MIL-PRF-81705	50	00000000	00000
1.231"	1 1/4"	9/16"	140°	10¹² ohms/sq	Pink	MIL-PRF-81705	50	00000000	00000
1.463"	1 1/2"	9/16"	140°	10¹² ohms/sq	Pink	MIL-PRF-81705	50	00000000	00000

Conductive Round Caps

With a surface resistivity of less than 10⁵ ohms/sq, these caps not only dissipate electrical charges, but can be used as an electrical shield. All meet the static requirements of MIL-PRF-81705. They fit electrical connectors with straight threads as well as unthreaded bayonet-type connectors.

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

Rigid Plastic
For OD	For Thread Dia.	Inside Ht.	Max. Temp., °F	Max. Surface Resistivity	Color	Specifications Met	Pkg. Qty.		Pkg.
0.244"	1/4"	15/32"	140°	10⁵ ohms/sq	Black	MIL-PRF-81705	50	00000000	000000
0.368"	3/8"	1/2"	140°	10⁵ ohms/sq	Black	MIL-PRF-81705	50	00000000	00000
0.487"	1/2"	1/2"	140°	10⁵ ohms/sq	Black	MIL-PRF-81705	50	00000000	00000
0.607"	5/8"	1/2"	140°	10⁵ ohms/sq	Black	MIL-PRF-81705	50	00000000	00000
0.73"	3/4"	1/2"	140°	10⁵ ohms/sq	Black	MIL-PRF-81705	25	00000000	00000
0.852"	7/8"	1/2"	140°	10⁵ ohms/sq	Black	MIL-PRF-81705	25	00000000	00000
0.992"	1"	1/2"	140°	10⁵ ohms/sq	Black	MIL-PRF-81705	25	00000000	00000
1.244"	1 1/4"	9/16"	140°	10⁵ ohms/sq	Black	MIL-PRF-81705	25	00000000	00000
1.478"	1 1/2"	9/16"	140°	10⁵ ohms/sq	Black	MIL-PRF-81705	25	00000000	00000

Threaded Caps

Aluminum

Protect externally threaded components from contaminants during fabrication and storage.

Aluminum caps withstand temperatures up to 650° F, which is more than four times as high as plastic caps. They are also more abrasion resistant. All meet military specification MIL-C-5501/3 for dust and moisture protection.

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

Thread
Size	Type	For OD	Inside Ht.	Max. Temp., °F	Specifications Met	Pkg. Qty.		Pkg.
Aluminum
For Straight-Thread Pipe
5/16"-24	UNF	5/16"	21/64"	650°	MIL-C-5501/3	50	0000000	000000
3/8"-24	UNF	3/8"	19/64"	650°	MIL-C-5501/3	50	0000000	00000
7/16"-20	UNF	7/16"	15/32"	650°	MIL-C-5501/3	50	0000000	0000
1/2"-20	UNF	1/2"	7/16"	650°	MIL-C-5501/3	50	0000000	00000
9/16"-18	UNF	9/16"	15/32"	650°	MIL-C-5501/3	50	0000000	00000
5/8"-18	UNF	5/8"	33/64"	650°	MIL-C-5501/3	50	0000000	00000
3/4"-16	UNF	3/4"	35/64"	650°	MIL-C-5501/3	50	0000000	00000
7/8"-14	UNF	7/8"	21/32"	650°	MIL-C-5501/3	50	0000000	00000
ForUNStraight-Thread Pipe
1 1/16"-12	UN	1 1/16"	49/64"	650°	MIL-C-5501/3	25	0000000	00000
1 5/16"-12	UN	1 5/16"	49/64"	650°	MIL-C-5501/3	25	0000000	00000
1 5/8"-12	UN	1 5/8"	23/32"	650°	MIL-C-5501/3	10	0000000	00000