Deltana SS4540R4BN 4-1/2" x 4-1/2" x 1/4" Radius Hinge, Ball Bearing, NRP, Stainless Steel (Pair)

That is what the SS45 Series stainless hinges are built for. The whole hinge is stainless steel, base material and all, so it resists corrosion far better than a plated steel hinge on salt air, pool decks and waterside exposure. The pin is non-removable and the knuckle runs on ball bearings, which is the combination you want on an out-swinging exterior door.

Only if the existing mortise has 1/4 inch radius corners. The SS4540R4BN is a 4-1/2 x 4-1/2 inch full mortise hinge with 1/4 inch radius corners, so it seats in a router-cut pocket of the same radius. If the door and jamb are cut square (the usual commercial hollow metal prep), the corners will not fill and you want a square corner hinge instead, such as the Orca Hardware 3535 Series 4-1/2 x 4-1/2 square corner ball bearing hinge. A 5/8 inch radius prep, common on residential doors, is also the wrong match.

NRP is a non-removable pin: a set screw in the barrel captures the pin so it cannot be driven out while the door is closed. It matters on any out-swinging door where the hinge barrels sit on the outside, which is most exterior residential entries and a lot of ground floor unit doors, because without it an intruder taps the pins and lifts the door off. On an in-swinging door the barrels are protected anyway and NRP costs you nothing but a screw.

The SS4540R4BN is sold as a pair, two hinges. A standard door up to 7 feet tall normally takes three hinges, so for one door order two pairs and you will have a spare leaf, or order per door accordingly. Screws come with them: #12 x 1-1/4 inch wood screws for a wood jamb and #12 x 1/2 inch machine screws for a metal frame, so nothing extra is needed to hang the door.

Deltana lists the SS45 Series as residential. It suits house entries, condo and apartment unit doors, and light multi-family work. For a high traffic commercial opening, a stairwell, or a labeled door, go to a heavy duty commercial hinge instead: the Don-Jo HWBB74545 is a heavy weight full mortise ball bearing hinge in the same 4-1/2 x 4-1/2 size, and the Hager BB1168 is a heavy duty full mortise ball bearing hinge that also comes NRP.

No. The SS4540R4BN is 4-1/2 x 4-1/2 inches and will not fill a mortise cut for a 4 inch or 3-1/2 inch hinge. Hinge size follows the mortise, not preference. For the smaller openings, ZenSupply carries matching sizes in other lines, such as the Orca Hardware 3514 Series at 3-1/2 x 3-1/2 with 1/4 inch radius corners and the 4014 Series at 4 x 4 with the same 1/4 inch radius. Note those are plain bearing and plated steel rather than stainless, so a mixed building will not have identical hinges on every door.

Ball bearing knuckles carry the weight of a heavy or frequently used door without the knuckle wearing and the door sagging, which is where plain bearing hinges give up first. The SS4540R4BN uses ball bearings, two ball bearing races (2BB). For a light interior door that gets opened a few times a day, a plain bearing hinge like the Orca Hardware 4014 Series 4 x 4 inch with 1/4 inch radius corners does the job. For an entry, a door with a closer on it, or anything solid core, stay with the ball bearing.

Leaf thickness is .134 inch. That is the number to check against the hinge already in your jamb, because a thicker or thinner leaf changes how the door sits in the opening. If the outgoing hinge is a different gauge you will be adjusting the mortise depth or shimming to keep the reveal even.

No handing to specify. A 4-1/2 x 4-1/2 full mortise butt hinge with radius corners is symmetrical, so the same pair hangs a left hand or right hand door. Handing only comes into it on hinges with a built in function, like the Stanley Security concealed conductor electrified hinge, which is ordered left-handed or right-handed because the wire exit has to be on the right side.

No. The SS4540R4BN is a plain butt hinge with no wire path through it, so it cannot carry power to an electrified lock or exit device. You need an electric through-wire hinge in that position: the Command Access ETH-BB68 is a heavy duty 5 knuckle energy transfer hinge, and the ETM-BB68 adds an integrated door position switch if you also need to monitor whether the door is closed. The remaining hinges on the opening can stay standard.

One finish: stainless steel. There is no plated or painted option in the SS45 Series, which is the point of it. The finish is the base metal, so a scratch on the job site does not expose a steel core to rust the way a chipped plated hinge does.