By Kent · Lock Depot Staff Writer

Measure the stile before you pick the device

The stile is the vertical edge of an aluminum or glass door, the frame of metal around the glass. It is the first thing I measure on a storefront, and it is the number that decides which Von Duprin rim exit device fits. Order the wrong width and the touch bar overhangs the glass, the latch does not land on the strike, or you cannot mount it at all.

Two part families get confused: the Von Duprin 55 and the Von Duprin 35A. Both are ANSI/BHMA A156.3 Grade 1 rim exit devices, UL listed for panic exit hardware with hex key dogging standard. They are built for different doors.

The 55: narrow stile

The 55 Series is the narrow stile rim device. It is made for aluminum storefront and glass doors where a standard-width exit device will not fit, and the catalog lists a minimum stile width of 1-3/4 in. (44 mm). It uses a crossbar design that spans nearly the full width of the door, so there is a wide area for someone to hit in an emergency. The mechanical warranty is 5 years.

The 55 is a handed device. It is set at the factory for left-hand reverse or right-hand reverse, so you have to know your door before you order. The listings I would start with, all in satin chrome (US26D):

• 55EO-US26D: exit only. Outside trim is not included.
• 55DT-US26D: with a dummy trim.
• 55NL-US26D: with a night latch.
• 55L-US26D-LHR: with a left-handed lever.

The 35A: wide stile

The 35A is the wider cousin. Its touch bar is non-handed and field-reversible, so one part number covers either swing. It carries a 10-year mechanical warranty. The catalog describes it as the wide stile version of the 33A, and says that if your stile is 4 inches or wider, the 35A is the best fit and gives the best look. The 3-foot listings are the ones to look at:

• 35A-EO-US26D-3: exit only.
• 35A-DT-US26D-3: dummy trim.
• 35A-NL-RHR-US26D-3: night latch, ships less cylinder.
• 35A-L-US26D-3-LHR: lever, ships less cylinder.

The measurement that decides it

Take a tape measure to the door and read the width of the stile, the flat metal border beside the glass, on the lock side. Measure the actual stile, not the door. A common mistake is to measure the door leaf and assume the stile is wider than it is.

• Under 1-3/4 inches: the 55 is not listed for it. Call us before you buy anything.
• 1-3/4 inches and up, on a narrow storefront stile: the 55 is the device built for it.
• 4 inches or wider: the 35A.

The catalog does not give a cutoff between those two, and I will not guess at one from here. If your stile falls in the middle, send a photo of the door with a tape measure held against the stile and we will tell you which one will sit properly. If you are working on a narrow aluminum storefront, the related reads are our piece on the Von Duprin 33A for an aluminum storefront door and our write-up on the Sargent 80 narrow stile exit device, which tackles the same stile question from another maker.

Handing: another reason to be careful

The 55 is handed and the 35A touch bar is not. That changes how you order. On the 55 you stand outside the door, decide which way it swings, and tell us left-hand reverse or right-hand reverse. Get it wrong and you have a device that does not fit the door. On the 35A you can relax on the touch bar, but the lever trim version is still handed, so check that too.

What the function letters mean

The same four functions appear on both. EO is exit only, with nothing on the outside. DT is a dummy trim, a pull with no function. NL is a night latch, where the outside is locked and opened by key and the inside is always free. L is a lever on the outside. The night latch and lever versions of the 35A ship less cylinder, so plan for the cylinder when you order.

Why not use the 35A on every door?

A customer asked me that last year, and on a wide stile it is the right instinct. The 35A has the longer warranty and the touch bar that works for either swing. The reason it is not the answer on every door is simple geometry: the device has to fit on the stile. On a narrow aluminum storefront there is nowhere to put it. That is why the 55 exists. It is a handed crossbar device listed for stiles down to 1-3/4 in., so it goes where the 35A does not fit.

The reverse mistake is rarer but I have seen it. Someone puts a narrow stile device on a wide stile door because that is what was in the truck. It will probably work, but the appearance and the fit are not what the wide stile device was designed to give you, and the catalog says plainly that the 35A is the better choice at 4 inches or wider.

Dogging on both

Both families carry hex key dogging as standard, so either one can be held open during business hours and released at night. As always, a dogged device is an unlatched door, so check with your inspector before you make it a habit on a door with a fire label.

Common questions

What is the minimum stile width for a Von Duprin 55?

The catalog lists a minimum stile width of 1-3/4 in. (44 mm).

Is the Von Duprin 55 handed?

Yes. It is factory-set for left-hand reverse or right-hand reverse, so verify the swing before you order.

Is the Von Duprin 35A handed?

The touch bar is non-handed and field-reversible. The lever trim version is handed.

Which Von Duprin device fits a wide stile?

The 35A. The catalog recommends it for a stile of 4 inches or wider.

Do these devices come with a lock cylinder?

The exit only versions need no cylinder. The 35A night latch and lever versions ship less cylinder.

The full range is on our Von Duprin page. Send us a photo of your door and the stile measurement and we will point you to the right one.