Planning and Dimensional
Information

11 Ft. Diameter, Half Turn Series, Spiral Stair

Stock Number: USS11-42-HT
Stair Diameter: 11' - 0" (335.28)
Minimum Opening: 70" x 136" (177.8cm x 345.44cm)
Outside Radius: 66" (167.64cm)
Inside Radius: 21" (53.34
Stringer Width, Outer: 12 1/2" (31.75cm)
Stringer Width, Inner: 8" (20.32cm)
Stringer Thickness: 2" (50.8mm)
Tread Width at Outer Stringer: 16 5/8 " (42.22cm)
Tread Width at Inner Stringer: 6 7/8" (17.46cm)
Tread Thickness: 1 - 1/2" (38.1mm)
Tread Passageway: 41" (104.14cm)
Handrail Width: 3 - 1/2" (8.89cm) - Opt. 4 - 1/2" (11.43) or 5 - 1/2" (13.97cm)
Handrail Thickness: 2" (50.8mm)
Baluster Spacing: Approx. 6" (15.24cm), - Opt. 4" (10.16cm), or alternating 2", 3", 2"
Turn per Inch of Rise: 1.9 Degrees
Rise per Degree of Turn: 0.52" (1.32cm)
Floor to Floor Risers Degrees of Turn
74' to 82' (187.96cm to 208.28cm) 9 127 to 140 Degrees
>82" to 90" (208.28cm to 228.60cm) 10 140 to 155 Degrees
>90" to 98" (228.60cm to 248.92cm) 11 155 to 171 Degrees
>98" to 106" (248.92cm to 269.24crn) 12 171 to 186 Degrees
>106" to 114" (269.24cm to 289.56cm) 13 186 to 201 Degrees
>114" to 122" (289.56cm to 309.88cm) 14 201 to 216 Degrees
>122" to 130" (309.88cm to 330.20cm) 15 216 to 232 Degrees
Tread Capacity
lbs. / kgs.
528 / 238 Stair Capacity
lbs. / kgs.
@ 114" Ht.
6043 / 2741

Specifications for heights up to 190" (4.83m) are available upon request.