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Quick Verdict

Three decisions, in order. Side: a regular arm mounts on the pull side; top jamb and parallel arm mount on the push side, so exterior out-swinging doors get one of those two, keeping the closer inside. Stop: if a wall, floor, or overhead stop exists, order a plain arm (LCN REG or Rw/PA, EDA, Norton PR7500, Sargent 351 UO); if no stop is possible, buy it in the arm (LCN CUSH, SCUSH with a spring for wind, Norton CPS7500, Sargent 351 CPS). Hold-open: mechanical hold-open arms (LCN HCUSH, Norton CLP7500T, Sargent 351 PSH) go on non-rated doors only; fire doors get an alarm-released holder or nothing. The suffix changes the arm, not the cylinder: a 4040XP CUSH and a 4040XP REG share one cast iron body.

Regular arm, parallel arm, or top jamb: which side of the door does each mount on?

Regular arm (hinge side, pull side). Body on the door face on the side the door swings toward you, arm projecting perpendicular to the frame. Per Norton, the most power-efficient application and the only pull-side one with a double lever arm.

Top jamb (push side). Body on the frame face above the door, arm down to the top rail. It needs a top rail of just 2-1/8", the default for narrow-stile aluminum storefront, and Norton rates it the best door control for exterior out-swinging doors.

Parallel arm (push side). Body on the door face on the push side, forearm folded almost parallel to the door, soffit shoe under the frame stop. Least projection, hardest to grab, the only mount that accepts stop arms. The cost is efficiency (about 25% below a regular arm per Norton) and top rail: 5-3/8" to 6-3/8", or a drop plate.

Mounting	Body on	Door side	Top rail / clearance	Use it when	Drawbacks
Regular arm	Door	Pull	Frame face and ceiling room	Interior doors, maximum power, 180° swing	Projecting arm, exposed to abuse, no stop arm
Top jamb	Frame	Push	2-1/8" top rail, frame face height	Exterior out-swing, narrow-rail storefront	Projecting arm, frame carries the body, no stop arm
Parallel arm	Door	Push	5-3/8" to 6-3/8" top rail, else drop plate	Exterior push side, corridors, schools, any door needing a stop arm	About 25% less efficient, stop arms cap swing

No frame face, no top rail, or an all-glass opening means no surface arm; see the guide to floor closers and pivots. Template layout and drilling live in the door closer installation guide.

Which door closer arm do I need for my door situation?

The mount answers "which side"; the arm answers "what happens at full open".

Door situation	Mount	Arm to order	Why
Exterior out-swing, wall stop exists	Parallel arm or top jamb	LCN Rw/PA or EDA, Norton PR7500, Sargent 351 UO	Plain arm costs less, swings wider
Exterior out-swing, no stop possible, wind or vandals	Parallel arm	LCN SCUSH, Norton CPS7500, Sargent 351 CPS	Cushioned stop absorbs slams
Corridor or classroom, door would hit a wall	Parallel arm	LCN CUSH, Norton CloserPlus, Sargent 351 CPS	Dead stop in the soffit shoe
Aluminum storefront, top rail under 5-3/8"	Top jamb	LCN 1461 REG, Norton 1601 tri-pack	Needs only 2-1/8" of top rail
Interior pull side, 180° swing	Regular arm	LCN REG, Norton 7500, Sargent 351 UO	Most efficient, no stop to limit swing
Non-rated door, hold-open plus stop	Parallel arm	LCN HCUSH or SHCUSH, Norton CLP7500T, Sargent 351 PSH	Holds at the stop, no wiring

Two things the table does not decide. Spring size (1 to 6) depends on door width, weight, and exposure, covered in the door closer sizing and adjustment guide; the only arm-related rule is to size for the mount. And when abuse is routine, no arm is enough alone: Norton sends extreme conditions to a Unitrol arm, and trade practice adds an overhead stop; see the overhead door stops and holders guide.

LCN arm codes decoded: REG, Rw/PA, EDA, CUSH, SCUSH, HCUSH, H, and ST-1630

LCN sells one cylinder per series and changes the suffix. On the 4040XP that cylinder is cast iron, 1-1/2" piston, Grade 1 to ANSI/BHMA A156.4, UL 10C, non-handed, size 1 to 6 on the Green Dial. Every code from EDA down is a parallel arm (push side) mount.

Code	Arm	Stop in arm	Hold-open	Order when
REG	Regular arm, hinge (pull) or top jamb (push)	No	No	Pull side or top jamb, stop by others
Rw/PA	Regular arm plus parallel arm shoe, any of the three mounts	No	No	Stocking SKU
EDA	Extra Duty Arm, forged	No	No	Abusive door that already has a stop
CUSH	Cush-n-Stop, forged steel main arm and forearm, stop in soffit shoe	Dead stop	No	No auxiliary stop possible, moderate abuse
SCUSH	Spring Cush-n-Stop, spring-loaded stop in soffit shoe	Spring stop	No	Wind, slamming, heavy abuse
HCUSH / SHCUSH	Hold-open Cush-n-Stop; SHCUSH adds the spring and a control handle	Dead or spring stop	At the stop	Non-rated door held open at the stop
H / Hw/PA	Hold-open regular arm with PA shoe, any of the three mounts	No	Yes	Non-rated pull side or top jamb

ST-1630 is a factory special template on the REG closer, not a different arm. The 4040XP REG regular arm closer is the pull-side default; the Rw/PA is the same closer with the parallel arm shoe added. The 4040XP SCUSH, about $621 at NLS, is the exterior push-side workhorse: the spring in the shoe takes the slam a rigid shoe sends into the top rail. The plain CUSH, about $551 at NLS, is the buy for interior corridors where the abuse is a cart, not the wind; the 4040XP HCUSH adds hold-open at the stop.

Norton and Sargent arm codes: 7500, CPS7500, PR7500, CLP7500T, and the 351 Powerglide

Both brands ship tri-pack closers that mount regular, top jamb, or parallel arm from one box, so their arm codes are about stops and hold-open.

Situation	LCN	Norton	Sargent
One SKU, any of the three mounts	4040XP Rw/PA	7500 Tri-Style	351 UO universal package
Pull-side regular arm, stop by others	4040XP REG	7500 or 8301/8501 regular arm	351 UO, regular position
Push side, heavy traffic, stop by others	4040XP EDA	PR7500 parallel rigid arm	351 UO, parallel position
Push side, dead stop in arm, moderate abuse	4040XP CUSH	CloserPlus arm, 85° to 110° in 5° steps	351 CPS compression stop, 85° to 105°
Push side, cushioned stop, wind and abuse	4040XP SCUSH	CPS7500 CloserPlus Spring	351 CPS, dead stop within 3°
Push side, stop plus hold-open	4040XP HCUSH / SHCUSH	CLP7500T, one point 85° to 110°	351 PSH, six positions 85° to 110°
Pull side or top jamb hold-open	4040XP Hw/PA	7500H ball-and-detent, 85° to 110°	351 UH universal hold-open

Norton. The CloserPlus arm dead stops the door at a soffit-plate stop set between 85° and 110° in 5° increments, and Norton limits it to moderate abuse. The CPS7500 CloserPlus Spring closer, about $575 at NLS, adds a steel buffer spring at the end of the opening cycle and comes with or without hold-open. The body-to-body verdict is in the LCN 4040XP vs Norton 7500 comparison.

Sargent. The 351 Powerglide body is non-handed, size 1 to 6 (factory set at 3), thru-bolted, UL 10C, ADA-compliant in every mount except push-side track. The 351 CPS heavy-duty parallel arm with compression stop is forged steel, stops between 85° and 105°, and is handed but field-reversible. The 351 PSH adds a six-position hold-open from 85° to 110° with a disengage.

Hold-open door closer options: hold-open arm, CUSH hold-open, track, or electromagnetic holder

1. Hold-open regular arm (LCN Hw/PA, Norton 7500H, Sargent 351 UH). Hold-open built into the arm; Norton's 7500H uses a ball and detent or roller effective from 85° to 110°. No stop function.

2. Hold-open stop arm (LCN HCUSH and SHCUSH, Norton CLP7500T, Sargent 351 PSH). Stop and hold-open in one forged parallel arm, holding at the stop angle. The fix for wedged doors.

3. Hold-open track. A slide track replaces the double lever arm, so nothing projects or can be hung on. The LCN 4040SEH-3038 track is listed to ANSI/BHMA A156.15, the closer-holder release-device standard, which makes it alarm-released hardware for LCN's electrically controlled 4040SE closers.

4. Electromagnetic holder or electrified closer. A wall or floor magnet, or an electrified closer, drops the door on alarm signal. More parts and wiring, but the only hold-open permitted on a fire door.

NFPA 80 requires fire door assemblies to be self-closing and positive latching, and a mechanical hold-open arm defeats both, so every mechanical hold-open arm belongs on non-rated openings. Rated doors that must stand open get an A156.15 release device tied to the alarm; the NFPA 80 annual fire door inspection guide lists what the inspector checks.

Retrofitting: changing the arm on an existing closer body, templates, drop plates, and handing

Same side, different arm. A 4040XP mounted parallel arm takes a Cush-n-Stop or spring hold-open arm without a new cylinder. The 4040XP-3049SCNS spring hold-open Cush-n-Stop arm, about $293 at NLS, is non-handed, forged, spring-loaded stop in the soffit shoe, handle-controlled hold-open. Pull the CUSH template first: the soffit shoe position differs from the PA shoe, so expect new soffit holes even when the body holes stay put.

Different side. Converting a pull-side regular arm to a push-side parallel arm is a relocation, not an arm swap: new body and shoe holes, a filler plate, priced as a new installation.

Different brand or series. Hole patterns do not cross over: LCN 4040XP 2-1/4" x 5", 4050A 2-3/8" x 6-3/4", 4111 2-1/2" x 6", 1461 1" x 7-1/2"; Norton 7500 ships retrofit plates; Sargent 351 ships thru bolts.

Drop plates and shoes. A drop plate lowers the body on a top rail under the 5-3/8" parallel arm minimum, or raises it on a frame face too narrow for top jamb; order it with the closer. The LCN 4050A-62A auxiliary shoe replaces the -62PA shoe when a parallel-mounted regular arm must coexist with an overhead holder or stop; it needs a 7-13/16" top rail.

Handing. Every body above is non-handed except the LCN 4111; Sargent's CPS and PSH arms and Norton's CLP7500T stop are handed but field-reversible. On the 4040XP only the metal cover (MC) is handed, ordered LH or RH, which is why NLS lists a 4040XP Rw/PA LH MC as its own SKU.

Common mistakes when ordering door closer arms

1. Regular arm on an exterior out-swinging door: the body ends up outside, on the vandal's side.

2. Stop arm on a door that already has a wall or floor stop: two stops fight and the arm loses. Use EDA, PR7500, or a plain parallel arm.

3. Rigid CUSH shoe on a wind-exposed door: specify the spring version, plus an overhead stop when gusts are routine.

4. Mechanical hold-open on a fire-rated door: an NFPA 80 violation on day one.

5. Parallel arm on a top rail under 5-3/8": the screws land in the glass stop. Add the drop plate to the order.

6. Stop arm on a door that must swing 180°: stop arms cap opening between 85° and 110°; only plain arms allow 180°.

FAQ

What is the difference between a parallel arm and a regular arm door closer?

A regular arm mounts the closer on the pull side with the arm projecting from the frame; a parallel arm mounts it on the push side with the arm folded along the door. The regular arm is about 25% more power-efficient; the parallel arm is cleaner, harder to vandalize, and accepts stop arms.

What does CUSH mean on an LCN 4040XP?

Cush-n-Stop: a forged parallel arm with a dead stop in the soffit shoe, for doors where a wall stop cannot be installed. SCUSH adds a spring-loaded stop, HCUSH adds hold-open at the stop, SHCUSH combines both.

Can I put a hold-open arm on a fire door?

Not a mechanical one. NFPA 80 requires fire doors to self-close and latch, so HCUSH, 7500H, PSH, and similar arms are limited to non-rated openings; rated doors that must stand open use an ANSI/BHMA A156.15 holder that releases on alarm.

What is the best parallel arm closer for an exterior door?

With no auxiliary stop, the LCN 4040XP SCUSH, Norton CPS7500, and Sargent 351 CPS are the Grade 1 answers; each puts a forged, cushioned stop in the parallel arm. With a wall or overhead stop in place, the 4040XP EDA or Norton PR7500 costs less and swings wider.

Next step

Match the door to a row in the decision table, then order the arm code, not just the series. Browse surface-mounted door closers, and for the most common case, an exterior push-side door with no stop, go straight to the LCN 4040XP CUSH closer. Orders placed before 3:00 p.m. EST ship same day from the Brooklyn, NY warehouse by UPS or FedEx, and ground shipping is free at $450 and up. For a mixed schedule, call the commercial desk at 718-814-6300; the desk will confirm arm codes, drop plates, and finishes before the order ships.