Dimensions Guide

Column
Nominal
Diameter
Shaft
Height
Shaft Bottom* Shaft Top*
Space Available
Inside Shaft:
Shaft Neck
Flute
Width (24
ea.)
Straight
Portion of
Shaft
Outside
Diameter
Inside
Diameter
Outside
Diameter
Inside
Diameter
For
Round
Post
For
Square
Post
Neck
Height†
Astragal
Ring‡
(A) (C) (D) (H) (I) (G) (F) (B)
18”
8’
17 3/8” 15” 14 5/16” 12 3/4” 12 3/8” 8 5/16” 7 7/8” 1” 1 1/2”
13 3/8”
9’ 25 3/8”
10’ 37 3/8”
12’ 61 3/8”
14’ 85 3/8”
16’ 26 1/8”
18’ 50 1/8”
20’ 74 1/8”
22’ 98 1/8”
24’ 122 1/8”
20”
6’
19 3/8” 18” 16 5/16” 14 7/8” 14 1/2” 10” 9 3/16” 1 3/8” 1 11/16”
0”
8’ 22 1/4”
10’ 46 1/4”
12’ 70 1/4”
14’ 40 3/8”
16’ 64 3/8”
18’ 88 3/8”
20’ 112 3/8”
24”
8’
23 3/8” 22” 19 5/16” 18” 17 5/8” 12 3/16” 12” 1 5/8”
8”
2 1/8”
10’ 32”
12’ 56”
14’ 24 13/16”
16’ 48 13/16”
18’ 72 13/16”
20’ 96 13/16”
22’ 120 13/16”
24’ 144 13/16”
* Diameters may vary ± 1/8”
† Neck Height is the distance from the top of the shaft to the top of the astragal ring, ± 1/8”.
‡ Astragal ring is only the ring portion, and does not include the fillet and cove.
(E)
(G)
(F)
(B)
(A)
(C)
(D)
(H)
(I)
Inside
Round
Top Diameter
Inside
Square
The “Space Available Inside Shaft” measurements are calculated
at the top inside diameter (with ± 3/8” tolerance), when using
Tuscan or Roman Doric caps. (Fluted columns may have reduced
tolerances.)
When structural or composite Ornamental Capitals are used, the
neck sleeve or plug will reduce the inside available space signifi-
cantly. If the column will not be required to carry a load, it may
be possible for the installer to modify or remove the neck sleeve
or plug to allow more interior space. Please contact Turncraft
Customer Service for more information.
These measurements are provided to assist in determining the
correct column diameter to go around a load bearing post or lally
column, or for clearance for water downspouts, conduits, etc. If
a larger diameter is required, it may be possible to specify the
Non-tapered Round columns instead.
POLY-CLASSIC ROUND SHAFT SPECIFICATIONS
ROUND TAPERED SHAFTS (CONT’D):
Column Diameter Concentric Load Eccentric Load*
6” 6,000 lb. 6,000 lb.
8” 10,000 lb. 6,600 lb.
10” 14,000 lb. 10,720 lb.
12” 18,000 lb. 13,200 lb.
14” 20,000 lb. 11,520 lb.
16” 20,000 lb. 13,200 lb
18” 20,000 lb. 9,040 lb.
20” 20,000 lb. 18,960 lb.
24” 20,000 lb. 13,200 lb.
*See testing documentation for full information on
eccentric loading values.
LOAD CAPACITIES:
Round Tapered Column Shafts