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400 Series Aluminum Single Sided Step Ladders

>Series Callout
The aluminum 400 series of Step Ladders has a duty rating of 375 pounds and features heavy gauge a TOOL-TRA-TOP®. All steps are knee braced and the TRACTION-TRED® steps are slip resistant. The rear rail is a full U channel and a full set of rear horizontals are spaced one per foot. The 14 ft and 16 ft models carry a duty rating of 300 pounds.


  • Aluminum top
  • Designed for one person jobs
  • Dual Drill Holster Top
  • Full set of rear horizontals
  • Knee-braced top & bottom steps and horizontals
  • Slip-resistant foot pad
  • Slip-resistant Traction-Tred steps

Performance Overview

StyleSizeReach HeightLoad Capacity
Single-Sided4 ft -- 16 ft8 ft -- 20 ft300 lbs -- 375 lbs


Top DimensionFront Rails DimensionFront Flange DimensionRear Rails DimensionRear Flange DimensionSteps Dimension
7 in x 14 in3-1/8 in1-1/8 in1-3/4 in1 in3 in


Model No.SizeReach HeightMax. Standing HeightLoad CapacityApprox. Product WidthApprox. SpreadBuy Online
4044 ft8 ft1 ft 11 in375 lbs21.24 in30-1/8 in
4066 ft10 ft3 ft 10 in375 lbs24.72 in42-7/16 in
4088 ft12 ft5 ft 9 in375 lbs28.25 in54-3/4 in
41010 ft14 ft7 ft 8 in375 lbs31.68 in67 in
41212 ft16 ft9 ft 7 in375 lbs35-1/4 in79-3/8 in
41414 ft18 ft11 ft 6 in300 lbs38.64 in91-11/16 in
41616 ft20 ft13 ft 5 in300 lbs42.24 in104 in

Type IAA duty rating is for stepladders up to 12 ft Designed for one or two person jobs. Note: When used as a double stepladder, the maximum load per side, including person and materials, shall not exceed the duty rating of ladder


Different types of ladders are designed to keep you safe and productive when climbing or standing. Using the wrong style of ladder or simply ignoring the limitations of climbing equipment can result in a fall or serious injury.
Height is referring to the actual ladder height. Extension ladders should be 7 to 10 feet longer than the highest support or contact point, which may be the wall or roof line. The highest standing level is four rungs down from the top. The highest permitted standing level on a stepladder is two steps down from the top.

Reach height is the maximum reach assuming a 5’6” person with a vertical 12” reach.
Ladders are designed to safely hold up to a specific amount of weight. The Werner Performance System defines five different capacities using a color and star rating system. The Duty Rating is defined as the maximum safe load capacity of the ladder. A person’s fully clothed weight plus the weight of any tools and materials that are carried onto the ladder must be less than the load capacity.

Werner offers ladder made from fiberglass and aluminum. Each material has characteristics which make it best for certain applications, or one material may simply fit the personal preferences of the user. For example, if working around electricity users should select fiberglass products due to their non-conductive side rails.