Why I'm Comparing Nylon and Teflon
I've been managing procurement for a mid-sized injection molding shop for about 7 years now. Our annual spend on engineering resins is roughly $180,000, and I've negotiated with maybe 15 different suppliers over that time. When people ask me which material is better—nylon or Teflon—my honest answer is: it depends on what you're trying to avoid paying for.
This isn't a debate about which polymer has higher tensile strength. I'm not a materials scientist. What I can tell you is which one has cost me less in rework, downtime, and warranty claims over the last six years of tracking every invoice in our ERP system.
Cost Per Part: The Surprise Wasn't Unit Price
Here's the part that threw me early on. I calculated the unit cost for a specific bushing we make—about 50,000 units per year. Nylon 6/6 from a Celanese supply chain was $0.32 per part. A comparable Teflon (PTFE) part from a different supplier was $0.78. On paper, the choice seemed obvious.
Except: the Teflon parts lasted 3.7 times longer in our customer's high-friction application. Over a 12-month period, the nylon bushings failed after 4 months on average. The Teflon ones were still going at 18 months. That means the customer replaced the nylon part three times per year. At $0.32 each, that's $0.96 per year in material cost. The Teflon part at $0.78 lasted the full year—plus some. So the Teflon was cheaper on a per-year basis.
And that doesn't include the labor cost for replacement or the production downtime. Our customer reported about $200 per unplanned shutdown. That made the nylon version effectively $0.96 + (3 shutdowns × $200) = $600.96 per year in downtime. The Teflon version: $0.78 + $0 downtime. You see the difference.
Thermal Performance: Where Nylon Falls Short
If your application runs hot—say above 180°F continuous—nylon starts to degrade. I've seen it firsthand. We had a batch of nylon gears that deformed during a 200°F bake cycle. The customer rejected the entire lot. That was a $4,200 write-off.
Teflon, on the other hand, handles 500°F continuous without issues. It also doesn't absorb moisture, which nylon does. Nylon can absorb up to 8% water by weight, which changes its dimensions and mechanical properties. Teflon absorbs virtually nothing. For applications in humid environments, like marine or food processing, this matters a lot.
But here's the trade-off: Teflon is softer. It has lower wear resistance under abrasive conditions. If your part is rubbing against a rough surface, nylon might actually outlast Teflon. I learned this when we replaced a Teflon seal with a nylon one in a conveyor system. The nylon lasted 6 months; the Teflon failed in 2. So the advantage flips depending on abrasion vs. heat.
Chemical Resistance: Teflon Wins, But At a Cost
For chemical exposure, Teflon is basically unbeatable. It's inert to almost all acids, bases, and solvents. Nylon will degrade in strong acids (like sulfuric) and some alkalis. If your part contacts brake fluid or paint thinners, nylon is a bad idea.
However, processing Teflon is harder. It requires higher temperatures (around 675°F melt point) and special tooling. Most injection molding shops can't run PTFE efficiently. That adds to the tooling cost. I've paid up to $1,500 more for a custom Teflon mold compared to a nylon one because of the required hardness and heat control.
When to Pick Nylon (and When to Pick Teflon)
Based on my experience auditing Celanese contracts and tracking actual part performance, here's how I'd advise my team:
- Choose Nylon (Celanese Nylon 6/6 or 6/12) when:
- Your operating temperature stays below 180°F continuous
- There is no significant chemical exposure
- Wear resistance is the primary concern (nylon is tougher)
- You need fast cycle times and standard mold tooling
- Choose Teflon (or a PTFE-based resin) when:
- Your part sees temperatures above 250°F
- Chemical attack is inevitable (like in lab equipment or fuel systems)
- Dimensional stability in humid conditions is critical
- Lower friction (coefficient of friction around 0.05-0.1) is required
There's also a middle ground: Celanese's TPU (thermoplastic polyurethane) family, which bridges some of the gap. TPU offers better abrasion resistance than Teflon and better chemical resistance than nylon. But that's a different comparison. For today, if you're choosing between nylon and Teflon, think about the total cost over the part's lifetime—not just the unit price.
Honestly, I've made the wrong call on this before. In my first year, I ordered nylon parts for a high-heat application because the price was $0.05 cheaper per part. Cost us $4,000 in rework when the parts warped. That's a classic rookie mistake. Learn from mine.