Garage Door Spring Color Codes, Explained (DASMA TDS 171)

Look at the end coils of a torsion spring and you'll usually find a stripe of paint. That's not the manufacturer's branding — it's the wire size, coded per DASMA TDS 171, the industry standard that nearly every North American spring maker follows.

Two different color codes — don't mix them up

1. End-coil paint = wire size. Each standard wire diameter gets a color. Spot the color, and you know the wire gauge without measuring. The full chart is in DoorBot's free Spring Color Codes reference, in both inches and metric.

2. Cone color = wind direction. Red cone: right wind. Black cone: left wind. On a standard two-spring residential setup, the right-wind spring mounts on the left of the center bracket (viewed from inside), and vice versa. Install a spring with the wrong wind and the door won't balance — it physically can't.

The trap: colors repeat

There are more wire sizes than colors, so the sequence repeats. A gold stripe appears on more than one wire size up the range. On residential doors the door size and spring length usually make the answer obvious; on commercial work, or whenever the stakes are real, confirm with a quick 20-coil measurement. Color narrows it down; coil counting settles it.

When the paint is gone

Ten years of dust, rust, and garage life will erase the stripe. No paint, no problem: measure 20 coils with a tape, divide by 20, and the Wire Size tool snaps your number to the nearest standard gauge. Then run the spring through the spring identifier to see exactly what door weight it was built for.

Why this matters beyond identification

Reading the color code correctly is the difference between ordering a spring once and ordering it twice. It also catches the classic mismatched-pair problem — two springs of different wire sizes on the same door, which loads one spring harder and fails it early. If the colors on the left and right spring don't match, that door deserves a closer look with the diagnose flow.

Field rule: color to shortlist, coils to confirm, cones for direction. Bookmark the color chart — it works offline.