# AISC's Metric equiv. of HSS

• To: "'seaint(--nospam--at)seaint.org'" <seaint(--nospam--at)seaint.org>
• Subject: AISC's Metric equiv. of HSS
• From: "Sherman, William" <ShermanWC(--nospam--at)cdm.com>
• Date: Tue, 21 Mar 2000 12:51:16 -0500
```Charlie, do you have a "quick trick" to convert hollow structural shapes
(HSS) from US Customary to Metric? One of our engineers called AISC and was
told to do a precise conversion and call out to decimal millimeters, eg HSS
8x6 becomes HSS 203.2x152.4 (using 25.4 mm/inch). This seems overly precise
to me.

-----Original Message-----
From: Charlie Carter [mailto:carter(--nospam--at)aiscmail.com]
Sent: Tuesday, March 21, 2000 10:37 AM
To: 'seaint(--nospam--at)seaint.org'
Subject: RE: AISC's Metric equiv. of WT13.5X51

The Metric Conversion of the AISC LRFD Manual of Steel Construction, 2nd
Edition lists all shapes as far as how they correspond between the U.S.
Customary and Metric series correspond. So does ASTM A6/A6M.

If you don't have either of those documents handy, here's a quick trick to
get a close estimate (often the exact listing) of the metric equivalent of
any U.S. W-shape in ASTM A6/A6M. Take the nominal depth, multiply it by 25
and round the resulting number to an increment of 10. Then take the lbs. per
ft, multiply it by 1.5 and round the resulting number to the nearest
increment of 1. For example, with a W21x44:

21 x 25 = 530
44 x 1.5 = 66

So a W21x44 in the U.S. customary series is a W530x66 in the metric series
(see ASTM A6/A6M). You can apply the same process to any other shape, too.
Just keep use the right factor for the units of measure. Also, rounding may
be different, but you get the idea.

Charlie

```