Can anyone briefly explain the differences between the standards of the Hollow Metal Manufacturers Association and the Steel Door Institute? I am sure there must be common ground.
The differences are BLURRED and they are on common ground. SDI members make custom hollow metal doors and pressed steel frames; HMMA member make standard hollow metal doors and pressed steel frames.
SDI members are members of HMMA and vice versa.
We kick off Part 2 with:
“Acceptable Manufacturers: Members of the Steel Door Institute (SDI) and of the Hollow Metal Manufacturers Association (HMMA) division of National Association of Architectural Metal Manufacturers or members of both, subject to compliance with the specified requirements.”
Wayne
When you study the actual standards, you will find minor differences in metal thicknesses, construction technique, etc. HMMA has several standards, so you can select one to specify around. Their most commonly cited standard, 861, was written around steel-stiffened doors which I don’t like. They now have 867 for laminated core doors which allows for other types of cores. Once I worked through all of these, I decided to write exclusively around HMMA 867 as it was closest to what I wanted, thus eliminating much of the need to ‘customize’ one of the standards. However, it was not a slam-dunk as to which standard to go with, and each of the others is good, too. I only recently decided this, after years of having it be a bit blurry to me, too. Although most manufacturers make doors to either SDI or HMMA, I think it’s best to pick one and stick with it througout.
Curious for me that this should come up today. I am spending most of the day updating my metal doors and frames section, because a contractor took exception to my required metal thicknesses for different door uses.
ANSI/SDI 250.8 lists 4 levels of doors:
Level 1, 0.032 (20 ga); Level 2, 0.042 ( (18 ga); Level 3 0.053 ( 16 ga.), Level 4, 0.067 (14 ga).
There are 2 models within each: full flush and seamless.
There are numerous variations on kinds of steel, core types, etc.
I had listed various levels for various uses.
The contractor in question wanted to use the old standard of 18 gauge doors, 16 gauge frames interior; 16 gauge doors, 14 gauge frames exterior.
Also I typically call for exterior and toilet room doors and frames to be made of galvanized steel. (Not that we get rain in Southern California, although it is pouring right now, but the sprinklers seem to be adjusted frequently to hit the doors halfway up). He didn’t say anything about those, so I don’t know if he will propose to furnish them, or just try to use primed steel. Once the primer is on, who knows the difference.
I’m interested to see what other specifiers are doing.
Thank you all for your constructive feedback.
I am somewhat ashamed to admit that HMMA is new to me - I’ve been specifying to SDI standards exclusively. I came across HMMA while updating Hans Meier’s “Library of Construction Specifications.” I naively assumed it was an outmoded reference.
Thanks again. This forum is monitored by so many knowing people.
The biggest difference has to do with the standard sizes of frames in SDI. SDI is built around “standard” sizes and profiles; HMMA is for “custom” work. You would use HMMA to specify a frame 8-3/4 inches deep with an 1-1/2 inch face and a return of 1/2 inch on one side and 7/8 inches on the other. Hey! It could happen. SDI frames simply would not be applicable.
As noted above, this difference is blurred because members of SDI are also members of HMMA and are capable of fabricating doors and frames to either standard.
Peter,
We regulary detail and specify exterior frames with 1" returns. Both SDI and HMMA member firms can provide this without heartburn. We also spec fully welded exterior frames with closed backs. Both SDI and HMMA member firms can provide this without heartburn.
We have asked the differences question with SDI members that furnish frames locally. These SDI members are also members of HMMA. No big deal.
Curries, SDI member, offers backbends to throat from 3/8" to 1-3/8".
Stiles is a HMMA member only and provide anything SDI members can provide. Depends on who is the low bidder that day.
It is not just membership, but the standard that makes a difference. The SDI standards do not deal with “custom” work while HMMA standards do. All frames (and doors) manufactured to SDI standards would, I believe, comply with with HMMA. Not all frames manufactured to HMMA standards would comply with SDI.
The fact that you want custom frames does not preclude using SDI standards. Reference standards should be used to define minimum requirements, then modified by stating exceptions to those standards. I’ve been specifying custom frames based on SDI specs for twenty years, haven’t had any problems. I looked at HMMA a few years ago, didn’t see anything that justified changing. As others have noted, many manufacturers are members of both SDI and HMMA, and should be comfortable bidding specifications based on either set of standards.