BEST 1ED7D4C228RP3626, E Series 7-Pin Slabbed Direct Motion Mortise Cylinder

The BEST 1ED7D4C228RP3626 is a 7-pin slabbed direct motion mortise cylinder from BEST's E Series. It's sold less core — the housing and cam assembly ship without any SFIC core installed, and the cylinder will not operate until a BEST 1C Series Small Format Interchangeable Core (SFIC) is inserted. If you're ordering this cylinder, you need to pair it with a compatible core. The part number tells you exactly what you're getting once you know the ordering procedure.

Breaking Down the Part Number: What 1ED7D4C228RP3 Means

BEST uses a structured part numbering system. The 1ED7D4C228RP3626 breaks down as follows:

1E = E Series slabbed cylinder family. D = Direct Motion (as opposed to E for Lost Motion — more on that below). 7 = 7-pin SFIC housing. D4 = Specific core configuration step in BEST's ordering procedure. C228 = Cabinet cam (C228 standard for 1E slabbed cylinders). RP3 = Ring Package 3 — the standard 7-pin mortise ring package. 626 = Finish: Satin Chrome (US26D).

Direct Motion vs Lost Motion: What the "D" Means

Direct motion (1ED Series) means the cam moves simultaneously with the plug as the key turns. The key turns, the cam turns, the lock operates. One-to-one action.

Lost motion (1EE Series) means the cam has a delay relative to the plug rotation. The key can be turned a certain degree before the cam engages. This is used in specific electrified lock applications where direct cam movement at the moment of key actuation is not desired.

For standard commercial mortise lock applications, the direct motion 1ED is the correct specification. Lost motion cylinders are specified for particular electric lock configurations — if you're not sure which you need, the 1ED is the default.

Slabbed Cylinder: What It Means and Why It Matters

"Slabbed" refers to the flat surfaces machined on both sides of the cylinder body. Standard mortise cylinders are round and can rotate in their mounting hole if the set screw backs out. A slabbed cylinder is threaded to the head and slabbed on both sides to prevent rotation in the mounting hole even if the set screw is removed or fails.

The 1E slabbed cylinder is threaded to the head and uses a hex nut for mounting. Cylinder diameter is 1-5/32" with the slab creating a 7/8" measurement across the flats. Thread specification: 1.150-32 (NS-2A).

C228 Cabinet Cam

The C228 is the cabinet cylinder cam standard for the 1E slabbed series. The cabinet cam prevents the key from being withdrawn in the unlocked position — the key can only be removed when the cylinder is in the locked position. This is intentional for cabinet and specific mortise applications where the key needs to confirm the locked state before it can be pulled.

Physical Specifications

Cylinder type: 1E Series slabbed, direct motion motise.

Diameter: 1-5/32" (slabbed), 7/8" across flats.

Length (7-pin, head to cam): 1-15/32" (37mm).

Thread: 1.150-32 (NS-2A).

Material: Solid brass or bronze.

Ring package: RP3 (7-pin mortise ring package — RP2 and RP5 rings).

Cam: C228 cabinet cam standard.

Finish: 626 Satin Chrome (US26D) standard.

Core: Less core — requires BEST 1C Series 7-pin SFIC core ordered separately.