Tom Rowland | Which is Stronger? Welded Loop vs Nail Knot | Tom Rowland Podcast Ep. 959

In this How 2 Tuesday episode of the Tom Rowland Podcast, host Tom Rowland tests which fly line loop connection is actually stronger: the manufacturer's pre-welded loop that comes on modern fly lines like the Cortland Precision, or the traditional loop created by doubling the line and tying nail knots with a Ti Fast nail knot tool. Many experienced fly fishermen cut off the welded loops because they don't trust them, especially when targeting species like tarpon. Tom puts both methods to a breaking test with surprising results that challenge conventional wisdom. If you've been cutting off those factory loops or wondering whether you should trust them on your next big fish, the results of this test might change how you rig your fly line forever.

The Old School Method: Nail Knot Loops

When you buy a new fly line today, most come with pre-made loops welded on both ends for easy loop-to-loop connections. But many experienced fly fishermen who've been at it for years simply don't trust these factory loops. Their reasoning is simple: they've never lost a tarpon the traditional way, so why start now? The old method involves cutting off the welded loop and creating your own by doubling over the fly line and securing it with nail knots. Tom demonstrates this technique using a Ti Fast nail knot tool, which he describes as probably the cheapest piece of fishing gear you could ever buy—a simple folded piece of aluminum that makes a really good knot every time. For anglers not confident in tying nail knots by hand, this tool ensures a perfect knot. But does this trusted traditional method actually hold up under pressure? Watch Tom demonstrate the nail knot loop technique starting at 00:02:37.

The Modern Alternative: Welded Loops

Modern fly lines like the Cortland Precision come with manufacturer's loops already welded onto both the front and back of the line. These loops are designed for quick loop-to-loop connections with your backing or leader, making rigging faster and supposedly more reliable. The welding process creates what manufacturers claim is a permanent connection that won't slip. Tom admits that many fly fishermen he knows automatically cut these off based on decades of habit and skepticism about factory connections. The question is whether this skepticism is justified or if technology has actually improved to the point where the welded loop outperforms the hand-tied alternative. Tom sets up to test the Cortland Precision's welded loop against his own nail knot creation. See the welded loop construction at 00:01:58.

The Break Test Results

Tom puts both loops under tension to see which fails first, and the results are genuinely surprising—even to him. When he asks if it surprised you, it's because it sure surprised him. The manufacturer's welded loop wasn't just stronger than the nail knot loop he created; it proved to be stronger than the fly line itself. The line actually broke down below the welded loop, while the loop remained perfectly intact with no compromise whatsoever. On the nail knot loop side, what happened was completely different: the loop didn't break, it slipped out of the nail knots. Tom acknowledges he could have possibly tightened them down better, but notes that he pulled pretty hard during the rigging process, as hard as he would on any actual fishing situation. The welded loop didn't slip at all. See the exact moment of failure at 00:03:29.

What This Means For Your Fly Fishing Rig

Based on these test results, Tom declares he will have 100% confidence in the manufacturer's welded loops going forward. This is a significant statement from someone who understands that many of his fellow fly fishermen have been cutting these loops off for years based on the assumption that hand-tied connections are more reliable. The data from this simple break test tells a different story: the welded loop is not the weak point in your system. In fact, it's stronger than the fly line itself, meaning your connection will hold before your line breaks. The nail knot loop, while traditional and trusted by many, actually failed by slipping rather than breaking, which could be even more problematic during a fight with a big fish. For tarpon anglers and anyone targeting species where every connection matters, this test provides clear evidence that modern manufacturing has caught up with—and surpassed—traditional hand-tied methods. Hear Tom's full conclusion starting at 00:03:40.

Final Thoughts from Tom

I'll be honest—this test surprised me. I've been around enough experienced fly fishermen to know that cutting off those welded loops is almost automatic for a lot of guys. They've caught fish their whole lives using nail knots, so why change? I get that mentality. But when you actually put these two methods side by side and pull until something fails, the results don't lie.

The welded loop didn't just hold—it held while the line itself broke. That means the connection is stronger than the weakest link in your system, which is exactly what you want. Meanwhile, the nail knot loop I tied slipped out. Could I have tied it tighter? Maybe. But I tied it the way I'd tie it if I was actually rigging a rod, and it still failed first. That's the kind of information you need to know before you hook into a big tarpon or any fish you really don't want to lose.

This is what How 2 Tuesday is all about—testing the things we assume we know and seeing what actually holds up. Sometimes the old ways are still the best ways. But sometimes, like in this case, the new technology has quietly gotten better than what we've been doing by hand. This test changed my mind about welded loops, and I think it's worth your time to watch the whole thing and see for yourself.