METRIC DESIGN GUIDE
Use metric bolt sizes in metric construction even though the steel sections are conversions.
See Structural/General section. It is important in modern friction fittings in steel construction
that bolts and holes use the same dimensioning system. Since the documents are metric, round
metric avoids confusion. A benefit of using ASTM A615M sizes is that there is a reduction in
the number of sizes of bolts, from nine to seven.
There are at least 20 firms that can make metric sizes. Minimum orders may be given in
dollars (0), or by number (500) or by at least a keg. Where minimums exist they are in this
Suspended Ceiling Systems
Suspended ceiling systems use round metric size in full scale metric construction. Many
manufacturers currently make these metric sizes.
Armstrong World Industries, PA, currently manufactures and sells round-metric-size
ceiling products. Except for selected specialty items, the major portion of the Armstrong
product line has already been or can be manufactured in round metric dimensions (Dan
Kennard, 717-396-2684/Deb Kantner, 717-396 3045).
Capaul Architectural Acoustics, Plainfield, IL, a medium-sized manufacturer, can produce
and bid round-metric-size projects (Tom Stanton, Baltimore MD, 410-234-0010).
Celotex Corporation, Tampa, FL, offers an entire product line of round metric sizes
(George Mitchell, 813-873-4027).
Chicago Metallic Corp., Chicago, IL, produces round-metric-size grids (Craig Trotier, 800-
National Rolling Mills, Malvern, PA, regularly makes round metric sizes (Rich Mattion
USG Interiors, Chicago, IL, regularly makes round-metric-size ceiling systems. Starting in
1994, this company will show all its round metric products and prices in its catalogue
(William E. Nelson, 312-606-5358/David C. Vanosdall, 312-606-3804).