Deltana S35R4N 3-1/2" x 3-1/2" x 1/4" Radius Hinge, NRP, Residential Thickness, Steel (Pair)

The S35R4N is a 3-1/2 x 3-1/2 inch full mortise hinge with 1/4 inch radius corners, so it drops into a mortise routed with a 1/4 inch radius corner cutter. If your existing mortises have square corners or a 5/8 inch radius (common on residential prehung doors), the leaf will not seat and you would need to re-route or pick a matching corner style. Pull one of the old hinges first and check both the leaf size and the corner radius against it.

NRP stands for non-removable pin. A set screw in the barrel captures the pin so it cannot be tapped out with the door closed. That matters on any out-swinging door where the hinge barrel is on the outside, exterior entries, storage rooms, mechanical closets. On an in-swinging door the barrels are already on the secure side and NRP buys you nothing. The S35R4N is the NRP version of the S35 radius corner hinge.

The Deltana S35R4N is made at 3-1/2 inch by 3-1/2 inch only. For a 4 inch by 4 inch leaf with the same 1/4 inch radius corner and plain bearing, the Orca Hardware 4014 Series is a 4 inch by 4 inch 1/4 inch radius corner plain bearing commercial hinge in medium duty. In square corner at that size the Orca 4040 Series is a 4 inch by 4 inch square corner plain bearing commercial hinge. On heavier doors calling for 4-1/2 inch, the Don-Jo HWBB74545 is a 4-1/2 inch by 4-1/2 inch heavy weight full mortise ball bearing hinge in satin chrome.

The Deltana S35R4N carries a non-removable pin and is built at residential thickness with a plain bearing at 3-1/2 inch by 3-1/2 inch, which addresses pin pulling on lighter interior and light residential openings. Where the opening calls for a heavier hinge with the same security feature, the Hager BB1168 is a non-removable pin full mortise ball bearing hinge rated heavy duty. For exterior residential doors without the NRP feature, the Delaney 4 inch by 4 inch bulk exterior residential hinge is a 5/8 inch radius pair.

They are both 3-1/2 inch by 3-1/2 inch steel residential hinges sold as a pair, but the corner radius differs. The Deltana S35R4N is cut with 1/4 inch radius corners, while the Delaney 3-1/2 inch by 3-1/2 inch bulk steel interior residential hinge uses a 5/8 inch radius. A 5/8 inch radius hinge will not fill a mortise routed for 1/4 inch radius, so check which radius the existing door was prepped for before swapping.

Wood screws are specified as #9 x 3/4 inch, which is the size that suits a wood jamb and a wood door stile. If you are hanging into a hollow metal frame or into a hollow core door edge you will want machine screws or a different fastener; the supplied wood screw is not the right fastener for steel frames.

Full mortise butt hinges like the S35R4N are non-handed, the same hinge works on a left hand or right hand door, you just flip it. Quantity is where people trip: they are sold by the pair, and a standard interior door takes three hinges, so one pair plus one more, or two pairs if you want a spare. Doors over 7 feet or unusually heavy slabs take four.

Eight finishes: Oil Rubbed Bronze, Brushed Nickel, Antique Nickel, Paint Black, Polished Chrome, Brushed Chrome, Polished Brass and Antique Brass. That covers the usual residential lever and knob finish families, so a property manager standardizing a building can pull hinges to match the locksets already on the doors. The finish is plated over a steel base.

The S35 steel hinges are a value choice for indoor applications, and the model is rated residential. Plated steel on an exposed exterior opening will corrode at the pin and knuckles over time, particularly in coastal or wet climates. For an exterior residential opening the Delaney 4 x 4 Bulk Residential Hinges for exterior use with a 5/8 inch radius are built for that duty, and the McKinney T2314 is a non-ferrous hinge if corrosion is the concern.

A plain bearing hinge has no bearing race between the knuckles, metal rides on metal, so it wears and can squeak under a heavy slab or a closer. The S35R4N at .085 leaf thickness is sized for a normal interior residential door. If the door is a solid core slab, has a closer on it, or has already worn its hinges out once, go to a bearing hinge instead: the Ives 3CB1HW is a heavy weight concealed bearing full mortise hinge, and the Orca 3535 Series is a ball bearing commercial hinge.

A plain bearing hinge such as the Deltana S35R4N does not stand in for hinges built around a specific function. An electrified opening needs a hinge that carries wire, such as the Command Access ETH-CB70 energy transfer hinge with a 3 knuckle standard weight steel base or the BEST CECB179-12C full mortise concealed bearing electrified hinge with 12-wire quick connect. Door position monitoring calls for the Command Access ETM-CB70 energy transfer monitor hinge with door position sensing. A self-closing opening needs the Stanley Security 4.5 inch by 4.5 inch full mortise square corner spring hinge, and a detention application uses the BEST BB855 heavy-duty steel double weight concealed ball bearing prison hinge.

The Deltana S35R4N is a plain bearing steel hinge at residential thickness, which is aimed at interior doors that see ordinary household or light traffic. Peers of the same construction include the Emtek 91013 residential duty plain bearing pair and the Ives 1010RP steel plain bearing residential hinge set of three, rated medium duty. Where the door is heavy or cycles constantly, the ball bearing peers are the Emtek 94013 heavy duty ball bearing hinge at 3-1/2 inch by 3-1/2 inch and the Orca Hardware 3535 Series 4-1/2 inch by 4-1/2 inch square corner ball bearing commercial hinge.

The Deltana S35R4N is a full mortise hinge, meaning both leaves recess into the door edge and the jamb. Full mortise peers include the Ives 3CB1 3-knuckle concealed bearing hinge in medium duty, the Don-Jo HWBB75045 heavy weight full mortise ball bearing hinge at 5 inch by 4-1/2 inch, and the McKinney MP79 MacPro 5-knuckle standard weight full mortise hinge. What is not interchangeable with a full mortise prep is the Hager 1129 half mortise plain bearing hinge or the Hager 990 STEEL full surface prison hinge, both of which mount differently at the frame.

At 3-1/2 inch by 3-1/2 inch, the Deltana S35R4N is a plain bearing steel hinge at residential thickness. Staying at the same leaf size in a heavier build, the Emtek 92013 is a heavy duty plain bearing hinge at 3-1/2 inch by 3-1/2 inch in plated steel with square corners, and the Emtek 96213 is a heavy duty hinge at the same 3-1/2 inch by 3-1/2 inch with square corners. Both use square corners, so confirm the existing mortise before ordering.

The unit of measure is a pair, and they are packed bulk in case quantities only. Plan the count in pairs across the whole job rather than per door, which suits a property manager rehanging a run of unit doors or a builder doing a subdivision. A single hinge is not an orderable unit here.

The S35R4N uses an arc hole pattern, meaning the four screw holes in each leaf are staggered on a curve rather than sitting in a straight line. Most residential butt hinges of this size use the same arc layout, so screws usually land in fresh wood next to the old holes rather than exactly in them. Have longer screws on hand if the old holes are stripped out at the jamb.

The Deltana S35R4N ships as a pair in steel at residential build, 3-1/2 inch by 3-1/2 inch. Other residential hinges sold by the pair are the Delaney 3-1/2 inch by 3-1/2 inch bulk steel interior residential hinge with a 5/8 inch radius, the Delaney 4 inch by 4 inch bulk exterior residential hinge with a 5/8 inch radius, and the Emtek 91013 residential duty plain bearing pair at 3-1/2 inch by 3-1/2 inch in plated steel. The Ives 1010RP residential plain bearing hinge comes as a set of three, which suits a single door in one order.

The Deltana S35R4N is a 3-1/2 inch by 3-1/2 inch steel hinge with 1/4 inch radius corners, offered in finishes including oil rubbed bronze, polished brass, antique brass, polished chrome and brushed nickel, so it already covers decorative finish work at that size. The McKinney SQ3331 is a square barrel 2-knuckle decorative hinge at 4-1/2 inch by 4-1/2 inch in standard duty, which is a different leaf size and barrel profile and needs a mortise cut for it rather than dropping into a 3-1/2 inch prep.