Cable materials FAQ


There’s a whole mess of complications behind the custom cable design and assembly process. A struggling supply chain. Booklets upon booklets of specification information and technical best practices guidelines.

Manufacturers should lean on their custom cable assembly suppliers for help. We’ve lent our ear to thousands of questions over the years. In this article, we answer some of the most common questions we receive from manufacturers.

What type of wire should I use for a general electronics cable?

We usually recommend UL 1569 wire for use in general applications. It’s rated for 300 volts and 105°C, PVC-insulated and typically available in high volumes and at affordable prices. We stock miles of it in every color, since we use it frequently.different wire types

What type of wire should I use in transportation applications?

We recommend GXL-rated wire for use in transportation applications because of its oil resistance. It’s insulated with cross-linked polyethylene (XLPE), which has a higher oil resistance than PVC. Pretty much every wire harness in your car is GXL-rated, and it’s both highly functional and easy to source.

What type of wire is best for extreme conditions?

When a customer needs their custom cable to perform in truly extreme conditions, we recommend Teflon-insulated wire. Teflon offers outstanding resistance to any type of disturbance or wear you could think of — other than, like, nuclear radiation. M16878/4 wire is a well-known military-specification wire rated for 200°C (and -70°C), but it is the most expensive wire type that is readily available on the market.

How can I make my cable more flexible?

The simplest way to change a cable for improved flexibility is to change the insulation type. Most cable jackets are made from PVC, but we steer customers toward cable with polyurethane (PUR) insulation when flexibility is a concern.

Another method to improve flexibility is to use wire with a higher strand count (the number of individual strands in the wire). Most 16 AWG wire is made of around 30 strands of 26 AWG wire. If you want a more flexible 16 AWG cable, look for 16 AWG wire with a strand count around 80, rather than 30. That performance comes at a cost, so take care to know what you need, or you’ll spend on extras that don’t add value.

What type of insulation is best for outdoor applications?

Cables that need to perform outdoors typically need UV resistance, weather resistance and heat resistance. Teflon insulation performs well in these conditions but is expensive. Polypropylene (PP) and high-density polyethylene (HDPE) also make for reliable outdoor wire insulation.

This chart by Olympic Wire provides a simple comparison of insulation materials.

What type of waterproof connector should I pick?

Plenty of connectors are rated for submersible use or resistance to high-pressure streams of water. An IP69 rating suggests best-in-class waterproofing. We tend to recommend two different connector series.

One is Aptiv’s Metri-Pack or Weather-Pack series. The other is TE Connectivity’s DEUTSCH connector series. Both perform well, but we prefer the Deutsch connector series because the sealing portion of the connector is a part of the connector itself, requiring no additional assembly. The sealing element of Aptiv’s connectors need to be applied to the terminal before assembling the cable, which adds a step to the production process.

How can I work around long cable component lead times?

Get creative with component sourcing if you’re worried about the lead time on some components you’ll need for your custom cable. One method that works well is making a risk buy.

If your product design isn’t finalized yet, and you’re unsure of market demand, but you’re confident that you’ll need a hard-to-acquire connector for the part’s cable, it could make sense to purchase a volume of the connector in advance.

When time comes to produce the cable, you can consign the connectors to your custom cable supplier.

Or, you could try something we’ve helped customers with before. Ask your cable supplier for a quote to buy an amount of a component and store it at their facility, so you’re not fighting a sluggish supply chain when you need it.MTI's Parts Tracker

How can I find cable component lead times?

If you’re in the process of cable component selection, you can always reach out to your cable supplier and ask about component lead times. If you want to do your own digging, we recommend searching for a part on or findchips.

Do I need my cables labeled?

There are three different situations where labelled custom cable makes sense.
1. A label would make cable installation significantly easier.
If you’re an OEM whose equipment requires complex installation with myriad electrical components, and you want to ensure simple and foolproof installation, then labelled cable probably makes sense for you. We build a lot of cables with multiple legs on them, and we use labels to make sure installers know what plugs in where.

Think about whether you need legs of cables, individual cables or cable bunches labelled. This depends on the point in your assembly and installation process where the label would provide the most value. Sometimes labelling cable bundles instead of individual cables can save manufacturers lots of money while still delivering the intended value.
2. Your part designs undergo frequent revisions
If your product’s design changes frequently, labels help you make sure customers receive up-to-date parts and can help maintenance technicians identify and solve problems. We’d recommend tagging each cable with a part number and revision number, so that anyone who grabs the cable from a part bin knows what version they’re holding.
3. You are dual-sourcing your cable
If you are sourcing a custom cable from more than one vendor, labels can help you identify and react to problems in case of quality issues. A vendor ID and date of manufacture makes a huge difference in these cases.
If none of these three factors apply to you, labels probably aren’t worth the cost. A good rule of thumb is about $0.75 per label. Depending on your order volume and the amount of labels per part you’re considering, that cost can add up fast.cable-management

Does the type of heat shrink I specify matter?

While most of the cable designs customers send our way don’t even specify a particular heat shrink type — merely “heat shrink tubing as required” — heat shrink characteristics can affect cable performance.
If you need to cover a splice point on a cable that will be outside, we’d recommend a dual-wall, adhesive-lined heat shrink tubing instead of single-wall heat shrink without adhesive. The reason: Water can breach single-wall heat shrink and cause your cable to fail at the splice point. Dual-wall heat shrink offers additional resilience against the elements.

Have more questions about custom cable?

Just get in touch with us. We love talking shop, and we respond to online requests in less than three business days.

We can lend you some engineering expertise, offer design advice or even kick off your next custom cable project. If you’re looking for more answers online, our manufacturer’s guide to custom cable is a great place to start.