A Purchasing Checklist for Metal Hose, Nylon Conduit, and Electrical Conduit Fittings

Who This Checklist Is For

If you're the person ordering conduit fittings for a facility, a contractor, or an internal project, you already know a $3 part can hold up a $3,000 install. I've been handling these orders since about 2022—roughly 60-70 purchase orders a year across maybe 8 different vendors—and I still get surprised. After one very avoidable mess in early 2023, I started using a fixed checklist before placing any order.

This works whether you're buying metal hose, nylon corrugated conduit, or electrical conduit glands. The principle is the same: match the spec to the actual installation, not to what the catalog listing calls it.

Five steps. Plus the mistakes I've already made so you don't have to.

Step 1: Match the Conduit Type to the Environment

Before you look at a single product page, answer this: where does this conduit actually go?

Indoor, dry, no vibration → nylon corrugated conduit is usually fine. Light, cheap, fast to run.

Outdoor, sun exposure, temperature swings → you need UV-rated outdoor nylon conduit. Standard nylon goes brittle in months. I've seen it crack along the flex lines after one summer.

Near motors, compressors, or anything that vibrates or gets hot → metal hose is the safer call. A flexible metal jacket handles heat and mechanical abuse in ways that no nylon product will. Not even close.

If you're ordering multiple types for one project, separate them by environment before you send the PO—not after the boxes arrive. Sounds basic. I've still watched someone install indoor-rated nylon on an exterior run (not me that time, thankfully).

Step 2: Split or Non-Split? This Is Where People Get Burned

Here's something most people don't realize until they've already ordered the wrong thing:

Non-split corrugated conduit requires you to feed the wire through it. You cannot wrap it around an existing run. The wire goes in first, then the conduit. That's the only way.

Split conduit—which, by the way, a lot of suppliers won't proactively suggest—opens along one side so you can fit it over wires that are already terminated and in place.

If you order non-split corrugated conduit for a retrofit job where the cables are already landed in a panel, you now own a pile of useless material and a rush order. That exact scenario cost me about $180 in wasted product plus a weekend of downtime I had to explain to operations. Not my best week.

Here's something vendors won't tell you: in a lot of catalogs, "non-split" and "split" conduit are the same base material. The difference is one manufacturing step—the cut. But the price difference is 15-20%. Confirm which you actually need before ordering either.

Step 3: Don't Forget the Supports—Outdoor Nylon Conduit Hangers and Nylon Bellows Brackets

The most common mistake I see from first-time buyers is ordering the conduit and forgetting the hardware that holds it up.

Every run needs support. For outdoor runs, that means outdoor nylon conduit hangers rated for UV exposure, temperature cycling, and the kind of weather that turns cheap metal brackets into rust stains within a year. Same thing for nylon bellows brackets—you need to verify the bracket matches the actual outside diameter of your conduit, not the nominal size.

That last point catches people off guard. A "3/4-inch" nylon conduit from one manufacturer can measure a few millimeters different from another brand's "3/4-inch." Check the OD on the spec sheet. Then measure a sample if you can.

And if you're selecting hangers for an outdoor run, leave a little slack. Conduit expands and contracts with temperature. A hanger that's too tight in July will crack the conduit in January.

Step 4: Electrical Conduit Glands—Check Threads and IP Rating

This is where things get technical fast. Electrical conduit glands have to match on two levels simultaneously: the thread and the seal.

Threads. NPT and metric are not interchangeable. Plenty of suppliers default to NPT, but if you're working with equipment enclosures from Europe or Asia, metric threads are increasingly common. Get the thread spec confirmed in writing before you order. If it's wrong, the gland won't seat, and forcing it damages the enclosure.

IP rating. For anything outdoors or in a washdown area, you want at minimum IP66, ideally IP68. IP54 keeps out splashes and might survive rain—but power washing will get through it. Specify the rating on the PO. Do not write "waterproof." That word means whatever the supplier wants it to mean.

Material compatibility. Nylon housings with brass glands in salt-air environments will corrode. Slowly at first, then all at once. For coastal installations, go with polyamide or PVC housings. If you're not sure, ask the supplier—that's a question that separates the ones who know their product from the ones who are just reselling.

Step 5: Vet the Vendor, Not Just the Product

Not every supplier should sell you everything. Took me a while to accept that.

The vendor with the best price on conduit might also list electrical conduit glands on their site. Maybe they even stock them. But stock isn't expertise. Stock is inventory. And there's a difference.

I've learned to pay attention when a supplier says, "We don't specialize in that—here's who does." That's a good sign. It means they know their lane and they're not going to sell you something they can't support. The distributor who claims to be great at everything is usually mediocre at most of it.

If I'm ordering nylon conduit and hangers, I want a vendor who can tell me the UV ratings and temperature ranges off the top of their head. If I'm buying electrical conduit glands, I want someone who asks about my thread standard before I bring it up. Those questions tell you whether you're dealing with a specialist or a middleman.

Common Mistakes That Cost Me Time and Money

• Ordering on price alone. The cheapest gland is often the one with the wrong IP rating printed on the bag. If the price seems too good, it probably is.
• Ignoring temperature range. Standard nylon softens around 105°C (221°F). If there's heat nearby—exhaust, motors, direct sun in summer—either switch to metal hose or specify a high-temp nylon grade.
• Estimating length instead of measuring. Corrugated conduit compresses slightly on bends, which eats usable length. Order 10% more than your measured run, not 10% less.
• No spec sheet from the supplier. If they can't provide written material specs, IP ratings, and thread standards, you're not buying a fitting—you're gambling on one.

These price ranges were accurate as of Q1 2025. Nylon and metal pricing shifts with resin and copper costs, so verify current rates before committing to a budget. If I remember correctly, nylon conduit went up almost 12% between 2023 and 2024—but don't quote me on the exact figure, it might have been closer to 9%.

When in doubt, ask for a sample before the full order. A supplier who won't send one is probably not planning to honor a return, either.