Tag Archives: Fittings

Why I Stopped Using Harbor Freight Air Fittings

In short, Harbor Freight quick couplers look like a cheap way to go.  The problem is that they are really soft.  I can’t even guess how many female fittings I have thrown away as they deformed and started to leak air.

The same goes for the soft male fittings.  You will find they abrade easily and leak air plus they bend and break easily.  The latest example is this male plug on my IR 117 air hammer where the smaller nipple is tearing away from the relatively thicker base:

My solution is simple – I only use Milton air fittings now and you can get them from Amazon at an affordable price.  Every time one of my many Harbor Freight units fails, I replace it.  By the way, I’m to the point that I don’t recommend any of the cheap import fittings regardless of maker.  Milton isn’t much more and they will last.

By the way, when you look purely at the purchase cost that doesn’t tell the whole story.  This fitting failed right at the start of the job and set me back about 10-15 minutes while I was rummaging around for my Milton spares, my teflon tape, the wrench, setting the tool in the vise to do the work, etc.   All of a sudden the supposed purchase savings doesn’t seem like a big deal.  By the way, I was swearing the whole time too 🙂

Here are the 1/4″ Milton M-type fittings that I use and recommend:

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Milton (S-210) 1/4″ NPT M-Style Coupler and Plug Kit, (12-Piece) (Tools & Hardware)

Milton (S-210) M-Style Coupler and Plug Kit, (12-Piece)
This pneumatic 12-pc. Milton (S-210) M-Style KWIK-CHANGE coupler/plug air accessory kit includes a variety of couplers, plugs and fittings with a 1/4″ basic flow size (air handling capacity). Milton M-Style Kwik Change couplers are made of brass, while M-Style Kwik Change plugs are made of case-hardened steel and are plated to resist rust. This collection of couplers and plugs:

– Will interchange with all manufacturers who comply with the dimensional requirements of military specification MIL-C-4109.
– Offer a maximum airflow of 40 standard cubic feet per minute.
– Offer a maximum of 300 pounds per square inch.
– Can withstand a max temperature of 250 degrees Fahrenheit.


(2) 1/4″ FNPT couplers
(8) 1/4″ MNPT plugs
(2) 1/4″ FNPT plugs

Singular Milton Item Part #’s:

#715 coupler (1/4″ FNPT)
#727 plug (1/4″ MNPT)
#728 plug (1/4″ FNPT)



  • BASIC FLOW SIZE: All 1/4″ body size air fittings. 1/4″ NPT. Buna-N seals.
  • KWIK-CHANGE: Interchangeable/compatible with most manufacturers. Easy push to connect.
  • MAXIMUM: 40 SCFM. 300 PSI. Temperatures up to 250 degrees F.
  • QUALITY: Durable brass couplers. Case-hardened steel plugs, plated to resist rust and corrosion.
  • M-STYLE KIT INCLUDES: (2) Female Couplers, (8) Male Plugs, and (2) Female Plugs. (Milton #715, #727, #728)

List Price: $22.73 USD
New From: $19.37 USD In Stock
Used from: Out of Stock
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