Aluminum Pipe Locknuts | McMaster-Carr

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16 Products

About Pipe and Fittings

Measure your pipe and fittings to identify their pipe size, thread size, schedule, and thread type. Then, find compatible components.

Low-Pressure Aluminum
Threaded Pipe Fittings

In addition to being lightweight, these aluminum fittings offer good corrosion resistance. Use them in low-pressure flow applications. To prevent cracking, do not tighten more than a 1/4-turn past hand tight.

Locknuts thread onto the male end of a fitting to provide extra holding power so the fitting won’t loosen from vibration.

NPTF (Dryseal) threads and NPSL (National Pipe Straight Locknut) threads are compatible with NPT threads.

Locknuts

For Use With: Air, Oil, Water
Pressure Class: 150
Pipe Nipples and Pipe: Use Schedule 40 aluminum
Flanges: Use Class 125 aluminum

NPSL Female
Pipe Size	Max. Pressure		Each
1/4	150 psi @ 72° F	44705K412	00000
3/8	150 psi @ 72° F	44705K413	0000
1/2	150 psi @ 72° F	44705K414	0000
3/4	150 psi @ 72° F	44705K415	00000
1	150 psi @ 72° F	44705K416	00000
1 1/4	150 psi @ 72° F	44705K417	00000
1 1/2	150 psi @ 72° F	44705K418	00000
2	150 psi @ 72° F	44705K419	00000
2 1/2	150 psi @ 72° F	44705K331	00000
3	150 psi @ 72° F	44705K332	00000

Locknuts for Metal Conduit Fittings

Zinc-Plated
Steel, 316 Stainless
Steel, and Aluminum

Secure threaded metal conduit fittings to a knockout in an outlet box or enclosure.

Zinc-plated steel, 316 stainless steel, and aluminum locknuts are compatible with NPSL and NPSM threads.

Aluminum
Pipe Size		Each
NPSM Threads
1/2	9147T123	00000
3/4	9147T124	0000
1	9147T125	0000
1 1/2	9147T127	00000
1 1/4	9147T126	0000
2	9147T128	00000

Low-Pressure AluminumThreaded Pipe Fittings

Locknuts for Metal Conduit Fittings

Low-Pressure Aluminum
Threaded Pipe Fittings