Mil. Spec. Caps | McMaster-Carr

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

REACH Compliant

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

RoHS Compliant

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

DFARS Specialty Metals
COTS-Exempt

	Specifications Met Specifications Met

MIL-PRF-81705

MIL-C-5501/3

	Maximum Surface Resistivity Maximum Surface Resistivity

10⁵ ohms

10¹² ohms

	Cap Type Cap Type


Push On	Screw On

	Height Height

	Hardness Hardness

Durometer 60A

Durometer 45D

Durometer 65D

	Inside Height Inside Height

	Thread Size Thread Size

View catalog pages (4)

Forward

How can we improve?

61 Products

Conductive Round Plugs

With a surface resistivity of less than 10⁵ ohms, 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, ohms	Max. Temp., °F	Hardness	Color	Specifications Met	Pkg. Qty.		Pkg.
15/32"	1/2"	5/8"	11/16"	10⁵	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	000000
19/32"	5/8"	5/8"	3/4"	10⁵	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	00000
23/32"	3/4"	5/8"	7/8"	10⁵	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	00000
27/32"	7/8"	5/8"	1 1/16"	10⁵	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	00000
31/32"	1"	5/8"	1 3/16"	10⁵	140°	Durometer 45D	Black	MIL-PRF-81705	50	00000000	00000
1 3/32"	1 1/8"	5/8"	1 1/4"	10⁵	140°	Durometer 45D	Black	MIL-PRF-81705	25	00000000	00000
1 7/32"	1 1/4"	5/8"	1 1/2"	10⁵	140°	Durometer 45D	Black	MIL-PRF-81705	25	00000000	00000
1 11/32"	1 3/8"	5/8"	1 17/32"	10⁵	140°	Durometer 45D	Black	MIL-PRF-81705	10	00000000	0000
1 15/32"	1 1/2"	5/8"	1 11/16"	10⁵	140°	Durometer 45D	Black	MIL-PRF-81705	25	00000000	00000
1 31/32"	2"	5/8"	2 5/32"	10⁵	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. 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, ohms	Max. Temp., °F	Hardness	Color	Specifications Met	Pkg. Qty.		Pkg.
15/32"	1/2"	5/8"	11/16"	10¹²	140°	Durometer 60A	Pink	MIL-PRF-81705	100	00000000	000000
19/32"	5/8"	5/8"	3/4"	10¹²	140°	Durometer 60A	Pink	MIL-PRF-81705	100	00000000	00000
21/32"	3/4"	5/8"	7/8"	10¹²	140°	Durometer 60A	Pink	MIL-PRF-81705	100	00000000	00000
27/32"	7/8"	5/8"	1 1/16"	10¹²	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
29/32"	1"	5/8"	1 1/8"	10¹²	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
1 1/32"	1 1/8"	5/8"	1 1/4"	10¹²	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
1 5/32"	1 1/4"	5/8"	1 7/16"	10¹²	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
1 15/32"	1 1/2"	5/8"	1 11/16"	10¹²	140°	Durometer 60A	Pink	MIL-PRF-81705	50	00000000	00000
1 31/32"	2"	5/8"	2 5/32"	10¹²	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. 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, ohms	Color	Specifications Met	Pkg. Qty.		Pkg.
0.245"	1/4"	1/2"	140°	10¹²	Pink	MIL-PRF-81705	100	00000000	000000
0.36"	3/8"	1/2"	140°	10¹²	Pink	MIL-PRF-81705	100	00000000	00000
0.48"	1/2"	1/2"	140°	10¹²	Pink	MIL-PRF-81705	100	00000000	00000
0.6"	5/8"	1/2"	140°	10¹²	Pink	MIL-PRF-81705	100	00000000	00000
0.72"	3/4"	1/2"	140°	10¹²	Pink	MIL-PRF-81705	100	00000000	00000
0.85"	7/8"	1/2"	140°	10¹²	Pink	MIL-PRF-81705	50	00000000	00000
0.973"	1"	1/2"	140°	10¹²	Pink	MIL-PRF-81705	50	00000000	00000
1.231"	1 1/4"	9/16"	140°	10¹²	Pink	MIL-PRF-81705	50	00000000	00000
1.463"	1 1/2"	9/16"	140°	10¹²	Pink	MIL-PRF-81705	50	00000000	00000

Conductive Round Caps

With a surface resistivity of less than 10⁵ ohms, 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, ohms	Color	Specifications Met	Pkg. Qty.		Pkg.
0.244"	1/4"	15/32"	140°	10⁵	Black	MIL-PRF-81705	50	00000000	000000
0.368"	3/8"	1/2"	140°	10⁵	Black	MIL-PRF-81705	50	00000000	00000
0.487"	1/2"	1/2"	140°	10⁵	Black	MIL-PRF-81705	50	00000000	00000
0.607"	5/8"	1/2"	140°	10⁵	Black	MIL-PRF-81705	50	00000000	00000
0.73"	3/4"	1/2"	140°	10⁵	Black	MIL-PRF-81705	25	00000000	00000
0.852"	7/8"	1/2"	140°	10⁵	Black	MIL-PRF-81705	25	00000000	00000
0.992"	1"	1/2"	140°	10⁵	Black	MIL-PRF-81705	25	00000000	00000
1.244"	1 1/4"	9/16"	140°	10⁵	Black	MIL-PRF-81705	25	00000000	00000
1.478"	1 1/2"	9/16"	140°	10⁵	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