Airbrush Hoses


Since there is variation in the fittings used on both airbrushes and the compressors that supply them with air, the choice of which hose to use can get complicated. If both come from the same company, then it’s usually easy: use their hose. But some companies sell more than one kind of hose, so it’s still important to know what your ends are when choosing one.

This has to be the worst-documented technology I’ve ever encountered. Tool compressors are relatively easy, even if they do assume that they don’t need to tell you what they use, because it’s all the same. But airbrush manufacturers and airbrush compressor manufacturers seem to think it’s sufficient to define things as “ours” and “theirs” and be done with it. There are a few exceptions, but even there I’ve found contradictory statements and confusion. Heck, one of the major manufacturers doesn’t even list all of the products they make in their catalog, merely noting that they produce adapters to allow “conversion of other manufacturers’” equipment to work with theirs. Maybe they don’t want to name names in their catalog, but really, how useful a statement is that without any detail?

And what’s more maddening is that while there are a number of standards in use, and the same company will sell more than one kind of hose, too often the packaging won’t identify the ends, or will simplly identify their size (e.g., 1/4”) but not their threading (NPT vs BSP). You need a secret decoder ring just to go shopping. This page is my index to what’s available as of the fall of 2013, since I need to do some shopping, and because I was curious as to just what was and wasn’t compatible. I may update it sporadically, but no guarantees.

For information about the difference between NPT and BSP, and all the various other labels used to identify airbrush and compressor connectors, see the Standards page. I’ve tried to normalize labels here to use the same label for the same technology, regardless of what name the vendor uses (e.g., 1/8” BSP rather than 1/8”G; the two more common of the four names for one standard, the others being 1/8” BSPP and DN 6 BSPP).

But the bottom line: most American airbrush compressors use some variation on one standard, and most European (and other) airbrush compressors use the BSP standard (which goes by several names). And you can’t connect American to European (or vice versa) without forcing them, and even then don’t expect to get a good seal. At the airbrush end of the hose, it’s more complex, but there are more adapters available as well.


Air-tool Compressors


In the United States, the typical air-tool compressor uses an NPT male connection. This may be as small as 1/4” NPT (and this size is common for air lines to power tools), but typically larger sizes are used, with reduction fittings available to adapt them to smaller hoses. Often a compressor will be sold with a quick-release fitting (for tools, not the same as an airbrush quick-release) screwed onto the NPT connection. NPT fittings typically don’t have seals (like washers or O-rings) because they make a gas-tight metal-on-metal seal when screwed down all the way.

In Europe and the UK, it’s likely that tool compressors are sold with BSP fittings (or their equivalent using DN or “G” nomenclature), but aside from seeing a few web sites listing these, I have no knowledge of what’s common over there. BSP fittings need some kind of gasket (washer or O-ring, but the washer may be metal) normally, although they can make a metal-on-metal seal where the washer would go; it’s not likely to be as good a seal as the other kind, but it may be adequate at the low pressures used in airbrushes.

So if you buy your compressor at the local home-supply store, or you buy one of these online, check to make sure what kind of connection it has, and buy the necessary size adapters to get it down to 1/4” (European DN 8) if it isn’t that already. And don’t be confused by the fact that the outside diameter of the 1/4” connector is actually 1/2” (about 13 mm actually). From there, you’ll need to know if it’s NPT or BSP (which would depend on what country you live in) and get hoses to match.

When connecting NPT fittings, use of liquid sealant or Teflon tape (PTFE) is recommended. However, if using tape use only 1.5 turns, as using more than 2 turns of tape will actually cause leakage rather than prevent it (this may only apply to high-pressure connections, as I’ve seen conflicting advice recommending more turns in other places).


Airbrush Compressors


According to online information, the majority of airbrush compressors appear to use 1/4” BSP male connections as their output. This includes Iwata, Harder & Steenbeck, and Grex.

Sparmax compressors use a 1/8” BSP male fitting.

Badger compressors are said to use a 1/4” NPT male fitting, however I believe this is actually a 1/4” NPSM male fitting (see the Standards page for further detail). NPT could be read as shorthand for this, but technically it isn’t correct since NPT is tapered and NPSM is not.

npsm-npt-male
Badger (NPSM?, left) and generic compressor NPT (right) 1/4” fittings

Aztec air compressors (now owned by Testors) use fittings described as 1/4” NPS. This may simply be a sloppy way of describing NPT (since “NPS” can mean “Nominal Pipe Size” and could apply equally well to NPT, BSP, or some other threading). Or it could be that they’re also using the NPSM connector, or some other kind of NPS connector. In any case, they use a special adapter to fit their hose to their compressor, so the hose has some other (possibly proprietary) connector on it.

An NPT (tapered) female on a hose or adapter should connect to an NPS (straight) male and make a good (although perhaps not great) seal; mechanically it may not be very strong. It’s also possible a BSP female would connect well enough to an NPSM (assuming thread-seal tape) to work at the low pressures used on an airbrush. It would be better to find an NPSM-to-whatever adapter, however I haven’t seen any adapters made for connecting third-party hoses to Badger compressors. This, to me, is a major negative to purchase of a Badger compressor. That doesn’t mean you can’t use someone else’s airbrush, since there are plenty of adapters to fitting airbrushes to Badger hoses. But the hose and compressor seem to go together.

Note: Paasche makes some kind of adapter to allow their hose to be used on a Badger compressor, but I’m uncertain of the details (see Paasche section below).


Hoses


There’s a dizzying variety of hoses available for airbrushes, in all sorts of incompatible forms. You can’t even be sure all of the hoses from one manufacturer will work with all of their airbrushes. After a great deal of online browsing to try to definitively answer this question, I went to a local artist’s supply store, and bought a bunch of hoses so I could compare them. The results were somewhat inconclusive. In part that’s because I lack a way to pressure-test them, so the fact that some of them seem to screw together when they should not doesn’t actually mean that they are compatible. Then I ordered some more online, which answered some questions, but raised others.

Airbrush hoses come in two kinds: simple smooth tubing (of vinyl or something similar), or braided “cloth” hoses. The cloth ones are actually rubber or PVC hoses with a protective cloth cover, usually made of nylon. These will last longer, and can operate at higher pressure than most smooth ones (the good ones handle up to 100 psi). They’ll also do a better job of evening out “pulsations” in the air if you don’t have a tank, and help cool the air (which makes a moisture trap near the brush more important in humid areas, since otherwise water will condense in the hose on the way to the brush and end up in your paint). Finally, the covered ones are usually more flexible, but trade that off for heavier weight.

The smooth ones may be vinyl or some other material, and come in both straight and coiled forms. Some people like the coiled hoses; I just find they get tangled on things. I prefer cloth hoses, but cloth or vinyl, straight or coiled, they all work. Some of the vinyl ones are rated for as low as 40 psi, but even that is likely to be plenty for any normal hobbyist use.

The usual hose length is about 10’ (3m). You can get longer ones, but you’ll lose some pressure in the hose. You can also get shorter ones, but then you have to put the noisy compressor very close to where you’re working. Some beginners sets come with a “free” hose that’s usually one of the shorter ones, and it may just be wasted money if you end up needing to buy a longer one.

Each airbrush manufacturer sells hoses that work with their airbrush and compressor. If you buy everything from one manufacturer, you won’t run into any problems. However, if you have more than one airbrush from different companies, or bought your airbrush from a different company than your compressor, you may run into compatibility problems. Fortunately lots of people have the same problems, so there are adapters available from the better supply stores to connect the usual suspects to each other.

Note: except as noted above for compressors, as a general rule you don’t need to use thread tape on airbrush hose fittings. These are precision-machined fittings and tape may be too bulky and actually make the seal worse.


Quick-Release Airbrush Connectors


You can get quick releases for connecting hoses to compressors, or airbrushes to hoses. These aren’t the same however, and selection of the former is very limited and appears to be specific to the compressors and hoses used by one manufacturer (although I haven’t researched this aspect closely). The quick-release that connects the airbrush to the hose is a different matter.

It would appear that the airbrush quick-release connectors made by Iwata, Harder & Steenbeck and Grex all use compatible quick-release junctions, so you can buy the airbrush parts and the hose parts from different companies and they will still work. I’ve listed the quick-release fittings I know about with their manufacturer below. And I think that’s the best approach: match hose to compressor, and use a quick-release fitting to adapt any airbrush to any hose. If you do that, life should be relatively simple.

Harder and Steenbeck describe theirs as a 2.7mm quick-release.


Aztec


Aztec, now owned by Testors, doesn’t make hoses other than the one that comes with its airbrushes. As noted above, these require an adapter to connect to their own compressors, so it’s probably a proprietary connector. At the airbrush end, I’ve read they reportedly use a 3/8”-32g fitting, whatever that is (male on the airbrush). However, another source said they use a Badger hose (I don’t think that’s right, but I don’t have an Aztec to compare).

Note: the “g” in this number does not appear to be the same as the “G” used in German standards to describe BSP fittings.

I have however seen adapters that go on the airbrush that allow use with an Iwata 1/8” hose connector (1/8” BSP). So while there may not be much you can do with the Aztec hose, you can use a better one if you want, presuming you can fit the other end of an Iwata hose to your air source.


Badger


Badger is probably the easiest kind to find in the U.S., with even relatively small arts and crafts stores selling a selection of airbrushes, compressors and parts. They make several standard hoses for their airbrushes. I have a couple of older braided nylon hoses which were blue and black, but these appear to be identical to the black ones currently in stores.

As noted above, if you buy a Badger compressor, you’re pretty much locked into using their hoses too, and putting adapters on the end if you want to use someone else’s airbrush. Thankfully there are a lot of those on the market.

Badger uses a metric M5x0.5mm male fitting on their airbrushes, so M5 below identifies the female version of this on the hoses. As noted above, Badger appears to use 1/4” NPSM male fittings on their compressor, so the hoses and fittings below described as 1/4” would be 1/4” NPSM female. Of course they don’t actually say this anywhere. However, note that Badger also uses the M5 fitting on their “Propel” regulator for canned air and on the 50-023 adapter, and a number of their hoses are M5-to-M5 for connecting those to an airbrush.

Note: some sites describe Badger as using M5x0.45 rather than M5x0.5 connector. The latter is more common, but I’m not sure the difference would matter in practice.

Note: Badger hoses will also fit Thayer & Chandler and Revell equipment. Badger owns Thayer & Chandler, and Revell is a reseller of Badger equipment with their own name on it.

50-4011, 10’ (3.05m) Re-coil coiled flexible hose (for Badger)
50-4012, 10’ (3.05m) Re-coil coiled flexible hose (for Paasche/Binks)

The following two hoses use M5 connectors on both ends, and require an adapter for use with 1/4” NPT compressors.
50-001, 5’ (1.9m) flexible lightweight hose
50-011, 8’ (3.05m) flexible lightweight hose with 50-023 adapter
50-023, 1/4” female NPT to M5 male adapter

NB: Badger identifies 50-011 as “8’ (3.05m)”. Since 3.05m is 10’, this is a bit ambiguous.

Heavy-duty rubber hose in braided fiber housing:
50-2011, 10’ (3.05m)
50-2022, 6’ (1.83m) with inline 50-2014 moisture trap
50-2025, 10’ (3.05m) with inline 50-2014 moisture trap
50-2018, 8’ (2.44m) with airbrush quick-connect fitting
50-3011, 10’ (3.05m) with 1/4” female at both ends (for model 400)

NB: It appears that all of these except 50-3011 are airbrush (M5) to compressor (1/4” NPT) hoses, except that I have one with M5 female fittings at both ends that requires use of the 50-023 adapter with a compressor. However that could be an older, now discontinued, part.

Although not listed on their website, my local store sells a 6’ Badger-branded braided hose with 1/4” NPT on one end and M5 on the other (without the moisture trap), part number 50-2010.

Transparent Vinyl Air Hose (limited to 50psi):
50-2030, 10’ (3.05m)
50-2026, 6’ (1.83m) with inline 50-2014 moisture trap
50-2021, 10’ (3.05m) with inline 50-2014 moisture trap
50-1011, 8’ (2.44m) with no fittings (for Bakery compressor)

NB: These are described (except for 50-1011) as having an airbrush (M5) fitting at one end, and “varying air source connection” at the other.

badger-ab-hose-ends
Badger, older 10’ hose, with metal-on-metal seals (1/4” NPSM left, M5 right)

One way to recognize this as a NPT fitting is the angled piece inside the larger brass fitting in the photo above. This is a 60-degree “chamfered” connector, typical of NPSM fittings and designed to mate with a similarly-angled fitting on the male end, pressure between them forces the edges of the chamfer out into the edges of the male fitting, creating a solid seal.


Grex


Grex makes a variety of hoses, mostly in 1/8” (BSP, I believe) for their own airbrush and compressor line, but with adapters allowing their hoses and quick-release for be used with a variety of other equipment.

GBH-06, 6’ Braided Nylon, 1/8” on both ends
GBH-10, 10’ Braided Nylon, 1/8” on both ends
GBH-20, 20’ Braided Nylon, 1/8” on both ends
GBH-30, 30’ Braided Nylon, 1/8” - 1/4”
GBH-30, 50’ Braided Nylon, 1/8” - 1/4”

Per their packaging, they also make hoses in 1/8”-1/4” and 1/4”-M5x0.45 versions.

They also make a variety of quick-release connectors:
AD03, 1/8” (hose) to 1/8” (airbrush) quick-release set (for Grex airbrush)
AD05, 1/8” male to 1/8” male (for joining two hoses or similar)
AD06, 1/8” female to 1/4” male adapter
AD08, M8x0.5 (hose) to 1/8” BSP airbrush quick-release set (Badger hose to Grex airbrush)
AD09, 1/8” female to male quick-release (Grex airbrush)
AD10, 1/4” male to 3/8” female
AD11, 1/8” female to 1/4” male (Grex airbrush on other hoses)
AD12, 1/8” male to 1/4” female (Grex hose on some compressors)
AD14, 1/8” female to M5 male (Grex airbrush on Badger hose)
AD16, M5 female to 1/8” male (Badger airbrush on Grex hose)
AD19, M5 female to male quick-release (Badger airbrushe)
AD28, Paasche male to 1/8” female (Grex airbrush on Paasche hose)
AD29, Paasche female to male quick-release (Paasche airbrushe)
AD30, Paasche female to 1/8” male (Paasche airbrush on Grex hose)

grex-ab-18-hose-ends
Grex GBH-10 1/8”F - 1/8”F, with O-ring seals


Harder and Steenbeck


Harder and Steenbeck make a variety of hoses and adapters. Some of these may be very hard to find, as the numbers came from a printed German catalog of uncertain age. H&S usually uses the terminology 1/8” G rather than 1/8” BSP (same connector, but the pre-metric German nomenclature rather than the pre-metric British nomenclature).

Hoses:
123883, 7.5’ clear hose, 1/4” to quick-release
123973, 7.5’ clear hose, 1/4” to quick-release (the description doesn’t indicate a difference from 123883)
125903, 9’ braided hose, 1/4” to quick-release
125913, 9’ braided hose, 1/4” to “adjustable” quick-release (see note 1 below)
125905, 15’ braided hose, 1/4” to quick-release
125915, 15’ braided hose, 1/4” to “adjustable” quick-release
125904, 20’ braided hose, 1/4” to quick-release
125914, 20’ braided hose, 1/4” to “adjustable” quick-release

They make the following “nd 2.7mm” quick releases and adapters for hoses and airbrushes. The quick release has a socket and slide-lock, the adapter has a post that fits into the socket.

Couplings (hose part):
104403, quick-release coupling 1/8” BSP male for hose with 1/8” BSP female (Iwata and Harder & Steenbeck).
104703, quick-release “adjustable” coupling 1/8” BSP male (as above, see note 1)
104473, quick-release coupling M5x0.45 male (Badger hose)
104723, quick-release “adjustable” coupling M5x0.45 male (Badger hose)
104413, quick-release coupling M5 male (not sure how this differs from above, may be M5x0.5 or x0.8)
104383, quick-release coupling 3/8”-32g male (for DeVilbiss, see note 2)
104423, quick-release coupling screw socket for 4x6mm clear hose
104603, quick-release “adjustable” coupling screw socket for 4x6mm clear hose
104433, quick-release coupling screw socket for 4x7mm hose
104533, quick-release coupling 1/4” BSP male for hose with 1/4” BSP female
104573, quick-release coupling with nipple for 4mm hose
104713, quick-release “adjustable” coupling with nipple for 4mm hose
104583, quick-release coupling M4 (NOT M5) male

Note: in the above, “screw socket” connectors go on the outside of the hose (with a tube inside), while “nipple” connectors are just a tube that plugs into a hose (typical aquarium-type connectors).

Couplings (NOT adapters, for airbrush or compressor):
104443, quick-release coupling M5 female (not clear if this is Badger M5 or another form)
104453, quick-release coupling 1/8” BSP female
104463, quick-release coupling 3/8”-32g female

Note: the above items are the quick-release socket, but with female screw-on connectors to attach them to something like an airbrush. It’s unclear to me what these would be used for.

These are probably also couplings as above, but I’m not sure of them:
104733, quick-release “adjustable” for braided hose
104753, quick-release for (something, says “hose nipple for braided hose”)

Quick-release Adapters (airbrush part):
104063, quick-release adapter with 1/8” BSP female (for H&S, Iwata and GRAFO airbrushes, except COLANI)
104083, quick-release adapter with M5x0.45 female (for Badger airbrushes)
104094, quick-release adapter with M7x0.75 female for EBFE airbrush (saw this as 104093 elsewhere)
104103, quick-release adapter with 3/8”-32g female for DeVilbiss airbrush (see note 2)
104323, quick-release adapter with Paasche female (for Paasche airbrushes)
104333, quick-release adapter with Aztec-compatible female for Aztec Airbrush
124173, quick-release adapter with M5x0.5 female (for “COLANI from 1998”)

Quick-release Adapters for hoses (to connect two hoses together?):
104073, adapter, with screw socket for 4x6mm hose
104053, adapter, with screw socket for 4x7mm hose

Hose connectors (with screw thread):
104133, connector with hose screw socket for 4x6mm hose to 1/8” BSP male
104143, connector with hose screw socket for 4x7mm hose to 1/8” BSP male
104153, connector with hose screw socket for 4x6mm hose to 1/8” BSP female
104163, connector with hose screw socket for 4x7mm hose to 1/8” BSP female
104483, connector with hose screw socket for 4x6mm hose to 1/4” BSP female
104493, connector with hose screw socket for 4x6mm hose to 1/4” BSP male
104503, connector with hose screw socket for 4x7mm hose to 1/4” BSP female
104513, connector with hose screw socket for 4x7mm hose to 1/4” BSP male
104563, connector with hose nipple for 4mm to 1/8” BSP male
104643, connector with hose screw socket for 2x4mm hose to 1/4” BSP female
104653, connector with hose screw socket for 2x4mm hose to 1/8” BSP female

Note: hose connectors go on bare hose (for custom-length and similar applications).

Other Adapters:
104763, adapter 1/4” BSP female to “most compressors” (not sure what that means)
104793, adapter, fit braided hose to Euro-Tec 10A
104783, adapter, for connecting clear hose to “module holder”
104773, adapter, for connecting braided hose to “module holder”
104683, adapter with 1/8” BSP female to M5(?) male (for Badger and Revell) - description just says 1/8” adapter for Badger/Revell

Notes:
1) An “adjustable” quick-release has a bleed-value air regulator for reducing pressure at the brush without resetting the compressor
2) I’m unsure of this, but that’s what their site said. The DeVilbiss I can find is a precision airbrush for automotive painting that uses a 1/4” NPS male connector on the airbrush. I’ve seen 3/8”-32g (whatever that is) mentioned in conjunction with Aztec, so this may be a typo, but what kind of typo isn’t clear. However, I’ve also seen 3/8”-32g mentioned in conjunction with DeVilbiss and Aerograph airbrushes on a variety of sites, so this may be something that varies by model.
3) The same part is listed as being for use with “4x6mm hose” in some places and for “clear hose” in others, so those would appear to be the same thing.

harder-steenbeck-10f-qr
H & S 10’ hose (125905)

Iwata


Iwata is a brand of Anest Iwata-Medea Inc, distributed in the Americas and the UK by Iwata Medea and in Europe by Anest Iwata Europe. I’m not sure who covers Asia or Australia.

In North America, they sell smooth polyurethane hosts in coiled and straight form in 6’ and 10’ (part DTI010) lengths, as well as a 10’ PVC hose covered in braided nylon. Based on online websites (as noted the catalog doesn’t list parts) these are:

CTI06, 6’ Coiled polyurethane, 1/4” - 1/8”
CTI10, 10’ Coiled polyurethane, 1/4” - 1/8”
CTI10RG, 10’ Coiled polyurethane, 1/4” - 1/4” (for RG-3 and W-100)
DTI06, 10’ Straight polyurethane, 1/4” - 1/8”
BT010, 10’ PVC Braided Nylon, 1/4” - 1/8”
BT050, 10’ PVC Braided Nylon, 1/4” - 1/4” (for RG-3 and W-100)

Those fittings are probably all BSP, although aside from “everyone knows” online info, I haven’t found a definitive statement. I’ve seen third-party websites describe Iwata hoses as using a 1/4” NPT fitting on the compressor end, despite having the same part number as those sold overseas. Iwata is mysteriously silent on this, and doesn’t list part numbers or fitting dimensions in their current catalog, except for their quick-disconnects, which are described as 1/4” with no further detail. My examination of one of their hoses suggests it’s BSP. There aren’t enough threads (depth of fitting) for a good NPT-type seal, and there’s an O-ring on the inside.

I tried connecting an Iwata hose to the NPT fitting on my Paasche regulator, and it only went 3 turns before jamming, not enough to engage the O-ring. I didn’t pressure test it, but I doubt it holds air. There is definitely a difference between NPT and BSP connectors (no surprise, but it’s always nice to see for myself).


iwata-ab-hose-ends
Iwata BT-010 1/4” - 1/8”, with O-ring seals

They also sell quick-connect fittings for both ends:

I1603, 1/8” - 1/8” (hose and Iwata airbrush fitting)
I1604, 1/8” airbrush fitting (to add 2nd airbrush)

Additionally, I’ve seen the following, although the part numbers may vary by store. Iwata doesn’t appear to list the part numbers, or even all of the fittings they sell, anywhere.

J001, Adapter - Iwata Airbrush to Paasche hose
J002, Adapter - Iwata Airbrush to Badger hose

012001, 1/4” male to 1/4” male adapter
012002, 1/4” male to 1/4” female adapter
022013, 1/4” female to 1/4” female adapter

HPA-J1, Airbrush Joint, 1/8F to 1/4M
HPA-J2, Airbrush Joint, 1/4F to 1/8M
HPA-QJP, quick-connect set


Paasche


Paasche is a U.S. company, and claims to use 1/4” NPT connectors. However the 6’ hose that came with my VL airbrush uses an O-ring seal. It’s not quite identical to the Iwata connector, being a few threads deeper, but otherwise they appear to be the same. This could be NPT in truth, or NPS without the chamfer that Badger uses. I’ve no way at present to check the threads to be sure. To deepen the mystery, 4’ and 10’ hoses I bought (A-1/8-4 and A-1/8-10) use a Badger-like tapered metal seal (see photos below), which could be a more normal NPT fitting or something Badger-compatible. Paasche’s own R-75 regulator clearly uses an NPT coupling on the output side, but screw onto my Badger compressor (with some thread tape) fairly well.

The airbrush end of their hoses is described as a: 1/8-1/4-40 coupling. I’m not sure what that means.

Coiled smooth airhose (100 psi rating):
CH-10, 10’, coiled hose with 1/4” and 1/8” connectors

Braided Nylon (red) hoses (100 psi rating):
A-1/8-4, 4’ Braided Nylon, 1/4” and 1/8” connectors
A-1/8-6, 6’ Braided Nylon, 1/4” and 1/8” connectors
A-1/8-8, 8’ Braided Nylon, 1/4” and 1/8” connectors
A-1/8-10, 10’ Braided Nylon, 1/4” and 1/8” connectors
A-1/8-15, 15’ Braided Nylon, 1/4” and 1/8” connectors
A-1/8-20, 20’ Braided Nylon, 1/4” and 1/8” connectors

A-1/8-10Q, A-1/8-10 plus quick-release
A-1/8-15Q, A-1/8-15 plus quick-release

Braided Nylon (red) hoses with inline moisture trap:
A-1/8-8MT, 8’ with 1/4” and 1/8” connectors
A-1/8-10MT, 10’ with 1/4” and 1/8” connectors
A-1/8-20MT, 20’ with 1/4” and 1/8” connectors

Braided Heavy-Duty (black) 3/16” airhose (appears to have 1/4” fittings on both ends):
HL-3/16-6, 6’
HL-3/16-8, 8’
HL-3/16-10, 10’

They also make quick-release couplings:
A-191, set for 1/8” hose and airbrush
A-192, additional 1/8” airbrush quick-release

And other adapters:
A-151, 1/8” NPT male to M5 female (Badger airbrush)
A-188, 1/8” NPT male to 1/8” BSP female (Iwata airbrush)
A-189, 1/8” NPT male to Aerograph Airbrush
DB-40, 1/8” NPT male to “62-1-3 or 62-2-3, 3 oz Sprayers”
HF-116, 1/4” NPT male to 1/8” NPT female (see note)

Note: HF-116 is explicitly described as being for Paasche Hose to Badger compressors, but Badger compressors don’t use a 1/8” NPT female fitting. This may be a M5 female to connect to Badgers own 50-023 adapter, but I haven’t seen a photo or anything to confirm that.

paasche-ab-hose-ends
Paasche, 6’ hose from VL Airbrush set, 1/4” - Paasche 1/8”, with O-ring seals

paasche-a-1-8-10
Paasche A-1/8-10, 1/4” - Paasche 1/8”, with metal seals