What is the DASMA extension spring color code chart?

If you have extension springs on your garage door, the colored paint stripe on the spring is a standardized weight code, not a manufacturer brand marking. DASMA (the Door and Access Systems Manufacturers Association) published TDS-171, which standardizes these colors across all compliant spring manufacturers. Here is how to read the code and why you cannot rely on color alone.

What DASMA TDS-171 defines and the complete color code table

DASMA Technical Data Sheet 171 (TDS-171) is the standard that defines extension spring color codes for residential garage doors. It was created so installers and homeowners could identify the weight rating of a spring without needing the manufacturer's catalog or the original installation records.

Before this standard, different manufacturers used different marking systems. A red spring from one maker could mean something entirely different from a red spring from another maker. TDS-171 resolved that by assigning specific colors to specific weight ranges and requiring all DASMA member manufacturers to follow the same scheme.

The color indicates the total weight that both springs together are rated to lift. Because extension spring systems use two springs (one on each side of the door), the color rating is for the pair, not each individual spring.

Paint Stripe Color	Lift Weight Range (per pair)
White	10, 110, or 210 lbs
Green	20, 120, or 220 lbs
Yellow	30, 130, or 230 lbs
Blue	40, 140, or 240 lbs
Red	50, 150, or 250 lbs
Brown	60, 160, or 260 lbs
Orange	70, 170, or 270 lbs
Gold	80, 180, or 280 lbs
Light Blue	90, 190, or 290 lbs
Tan	100, 200, or 300 lbs

The colors repeat across three 100-pound tiers. A white spring could be rated for 10, 110, or 210 pounds. A tan spring could be rated for 100, 200, or 300 pounds. The color tells you the rating within a tier but not which tier your door falls in.

Why colors repeat across tiers and what that means for you

Extension springs with the same color but different tiers have different physical characteristics. A spring rated for 210 pounds per pair has more coils, different wire gauge, or different stretch length than a spring rated for 10 pounds per pair with the same color. They are not interchangeable even though they have the same paint stripe.

This is the most important thing to understand about the DASMA color system: the color is not a full specification. It narrows the field but does not uniquely identify the spring. To order a replacement correctly, you also need the spring's stretched length, wire diameter, and coil count, or you need to know the door's actual weight so you can calculate the correct rating from scratch.

The color system was designed to help experienced installers identify springs in the field, not to allow homeowners to order springs by color alone. If you see a red-stripe spring on your door and order "red extension springs," you may receive springs rated for 50 pounds when your door weighs 150 pounds.

How to measure your door weight correctly

The only reliable way to get the right extension spring is to know your door's weight. Here are three methods:

Check the door manufacturer label. The side stile (the vertical edge of the door panel) usually has a label from the manufacturer that includes the door weight. Look for it near the top rail on the interior side of the door.

Read the spring dimensions and back-calculate. If you have the old spring in hand, measure the unstretched length, wire diameter, and inner coil diameter. Enter these dimensions into an extension spring rate calculator (available through spring suppliers). The calculator returns the spring's rate in pounds per inch. Multiply that rate by the standard extension (usually about 2 inches per foot of door height for most residential doors) to get the approximate lift force.

Use a fish scale or luggage scale. Disconnect the springs, prop the door open with a temporary support at mid-travel, and hook a scale to the bottom bracket. The reading tells you how much force is needed to lift the door at that point. This method is approximate and should only be done with the door secured against falling.

Extension springs vs. torsion springs and when to convert

Extension springs and torsion springs serve the same purpose (counterbalancing door weight) but in very different ways. Extension springs stretch as the door closes and store energy as tension. Torsion springs wind around a shaft above the door opening and store energy as torque.

Extension springs are common on older and lower-headroom doors because they fit in the horizontal track area. Torsion springs require a solid header above the door for the tube and shaft assembly. Extension springs are generally considered less safe than torsion springs because a broken extension spring can fly across the garage if safety cables are not installed. Safety cables inside each extension spring are required to contain a broken spring.

If your door has extension springs and you are replacing them, it is also worth evaluating a conversion to torsion springs. Torsion spring systems provide more even lifting force, last longer, and are safer when one spring fails. The conversion requires a torsion tube header bracket kit and is practical on most doors with 10 or more inches of headroom above the opening.

How to order replacement springs correctly and what to ask

When you contact a supplier, give them these four pieces of information:

1. Door weight in pounds
2. Door height in inches
3. Unstretched spring length in inches
4. Wire diameter in inches (measure with a caliper across the wire cross-section)

With those four numbers, the supplier can specify the correct DASMA-rated extension spring pair for your door. The color code they return should match the current spring if the original springs were correct for the door.

Also specify the wind direction: extension springs come in left and right versions for the left and right side of the door. These are not interchangeable. The springs coil in opposite directions so that they pull the cable in the correct direction on each side. If you order two left-hand springs by mistake, only one side will work correctly.

Extension spring stretch length matters too. Extension springs are sold in standard stretched lengths. Most residential doors use springs that stretch to about 2 inches per foot of door height. For a 7-foot door, that is roughly 14 inches of additional stretch when the door is fully closed. The spring must be long enough in its relaxed state to accommodate that stretch plus the mounting hardware on each end.

If you are buying online, confirm that the supplier is selling DASMA TDS-171 compliant springs and that they will match the color code to the weight tier you need, not just the color. A good supplier asks for door weight and door height before accepting an order for extension springs. If a site lets you add extension springs to a cart by color alone, that is a warning sign.

G Brothers Garage Doors serves the Denver metro and Front Range. We can identify the correct spring rating for your door, source the springs, and install them with safety cables. Free written estimates, same-day service available. Licensed and insured.