P900 Series
-
The "P"
The “P” in the part number stands for Plug-End, which refers to the style of the spring’s end. You’ll see this type of end in the product photo.
-
The "9"
The first number after the "P", in this case, 9, refers to the gauge of the wire. The P900 Series is the smallest in the "P" series.
-
The Last 2 Numbers
The last two numbers in the spring code (like “28") tell you the length of the spring, measured in inches. So if you see “28,” that means the spring is 28 inches long, not including the end.
Collapsible content
Spring Weight
P928 = 4.1 LBS
Spring Length
The length has nothing to do with the weight of the door, but everything to do with the height of the door.
P928 = 7'0" High
Initial Tension
The initial tension is determined by how many pounds of pull force it takes to stretch the spring 1 inch.
Our P900 Series spring, length 28 has an intial tension of 45-55 pounds.
Wire Type
All of our springs are composed of ASTM (American Society for Testing and Materials) 229 oil-tempered wire.
This specific one-piece extension spring uses 9 gauge wire which refers to the thickness of the wire.