Servicing Schlage F Series Locks

June 1, 2010
The keyed F Series locks have a five-pin tumbler “C” keyway lock cylinder.

Schlage F Series locks have become popular with residential applications in the past years. The F Series locks are available in keyed and non-keyed configurations having both lever and knob lock options for standalone applications and integration with handlesets. The keyed F Series locks have a five-pin tumbler “C” keyway lock cylinder.

To satisfy a number of requests for servicing information, I have compiled a brief history and servicing information for the keyed F Series knob and lever locks.

Using my Schlage Lock catalogs as a guide, Schlage introduced the F Series cylindrical locks in the early 1930s as “small” knob locks for residences and apartments. These locks were available keyless or with a five wafer tumbler lock operated by a single-sided utility lock type of round head key. One thousand changes were available. According to the catalog, locks could not be master keyed.

They disappeared from the Schlage Lock catalogs by the 1940s and returned as non-keyed cylindrical locks in the mid-1960s to accommodate non-keyed functions for other lock series.

Around early to mid-1980s, Schlage introduced the new F Series tubular keyed knobsets with pin tumbler lock cylinders. These residential entry knobsets, like the A and D Series, were equipped with a two-piece keyed knob. The A and D Series cylindrical knobsets during that time are manufactured to accept six-pin tumbler lock cylinders.

The five-pin tumbler lock cylinder for the F series two-piece knobset has been a zinc plug and body since it was introduced or very shortly thereafter. The zinc lock cylinder body of the F Series two-piece knob is similar in shape to the machined brass lock cylinders used by the A and D Series locks. The rear of the plug performs the task of driver cam and receiver of the locking/unlocking bar. A retaining ring secures the plug into the F Series lock cylinder body. The F series continues to use the zinc cylinder today. These lock cylinders are designed to rotate only 90 degrees in both directions.

To service these two-piece knob locks, the exterior knob is removed from the lock assembly. The operating key had to be inserted and rotated approximately 45 degrees to clear the catch obstruction. With the key rotated, press the catch to release the knob. Slide the keyed knob off of the lock assembly. With the knob free, slide the sleeve off the back of the knob. There is an open slot large enough for the standard sized lock cylinder to slide out.

The F Series keyed locks have a similar plug diameter as the machined brass lock cylinder. This means the same Schlage ten lengths of bottom pins (0-9) and three lengths of top pins (1-3) to combinate the F Series lock cylinders. The number one top pin is .235” long and is used with bottom pin lengths 0, 1, 2, 3. The number two top pin is .200” long and used with bottom pin lengths 4, 5, 6. The number three top pin is .165” long and used with bottom pin lengths 7, 8, 9. The three lengths of top pins are designed to balance out the pin stacks.

Schlage’s part number for the keyed “F” Series lock cylinder in the two-piece Orbit design knob is 29-003. For the Plymouth, Claremont, Georgian and Bell knob designs, the part number is 29-002. The different part numbers are not interchangeable.

During the last quarter of 2004, Schlage sent out notification of the F Series keyed lock’s exterior knob design change from two pieces to a one-piece knob. This change required shortening the height of the lock cylinder bible. In order to accommodate the zero through nine depths of cut and their top pins, the pin stack still needed the standard height dimension of the lock cylinders used in the two-piece keyed knobs.

Schlage solved this problem by developing a spring loaded spring retainer that could extend to the height needed to maintain the appropriate stack height and be compressed to permit removal and installation of the lock cylinder from and into a one-piece knob.

This new F Series lock cylinder’s almost rectangular-shaped spring loaded spring retainer provided the additional height. It clips on with tabs that slide up and down within the accommodating slots in the bible. When this new spring loaded lock cylinder was seated within the knob, the spring loaded spring retainer would raise up being lifted by the pin tumbler springs to provide the appropriate overall height.

The spring loaded spring retainer could be compressed onto the top of the bible enough to permit the lock cylinder to slide out of and into the one-piece knob. The lock cylinder could be pushed out of the back of the knob by applying pressure to the top of the lock cylinder plug face. If the lock cylinder will not slide out, use a lock pick, turning tool or similar object to compress the spring retainer.

Note: When sliding the lock cylinder into or out of the one-piece knob, make sure the spring retainer or the cylinder body does not line up with the knob guide. This punched indent in the knob body will obstruct the lock cylinder from being removed.

Schlage’s part number for the keyed “F” Series knob lock cylinder in the one-piece Orbit design knob is 29-017. For the Plymouth, Siena, Georgian and Bell knob designs, the part number is 29-016. The different part numbers are not interchangeable.

Schlage introduced the F Series leversets using a similar design to the F Series one-piece knobset with a different sized driver cam and receiver. A retaining ring secures the plug into the F Series leverset lock cylinder body.

The part number for the keyed “F” Series keyed lever lock cylinders in the Accent and the Flair is 29-018. For the “FA” Series keyed knobsets, Andover and Danbury designs, the part number is 29-016. For the “FA” Series keyed knob lock cylinders in the Andover and the Danbury designs, the part number is 29-300. For the “FA” Series keyed lever lock cylinders in the Callington, Champagne and St. Annes designs, the part number is 29-301. The different part numbers are not interchangeable.

Note: The FA Series locks can be distinguished from the F Series as the FA Series locks have concealed mounting screws.

The servicing procedure for the F and FA Series keyed levers is similar to the keyed one-piece knob locks. Both the lever and one piece knob locks use the Schlage spring loaded spring retainers.

Since these lock cylinders have a shorter bible, Schlage reduced the number of top pins to two and modified the overall length of the new Top T-Pin. These F Series locks continue to use the number three top pin that is .165” long and used in conjunction with bottom pin lengths 7, 8, 9. The modified Top T-Pin is approximately .170” long with the tapered upper portion approximately .105”. This smaller diameter permits the spring to slide down onto the tapered shaft. According to Schlage, use the T-Pin Top Springs only when using the Top T-Pins. These springs are manufactured of phosphor bronze and designed specifically for use with T-Top Pins. These springs have a bright finish, not brass. Brass springs are used with the number three top pin.

Use the Schlage F Series Keying Kit, part number 40-134, to combinate the F and FA Series one-piece knob locks and lever locks. This keying kit contains the ten (0-9) bottom pins, the number three (.165” length) top pin and the Top T-Pin. The number 3 top pin is designed for use with pin depths 7-9.

I checked the key bittings of a number of Schlage F Series one-piece knob locks and lever locks. Of the more than one dozen locks I examined, none of the key bittings contained a depth of cut of zero, one, two or three. In addition, each key bitting contained at least two depths of cut between seven and nine. For example, key bitting 87567 and 94469. Both of these key bittings contain at least two depths of cut seven or greater, having at least two #3 top pins.

When changing the combination of a Schlage F Series one piece knob or lever lock, change the top pins as well as the bottom pins to ensure proper operation and security according to factory specifications.

Editor’s Note: The information discussed in this article covers the F Series keyed knob and the F and FA Series keyed lever locks only. I would like to thank Schlage for their help in obtaining the following information.

For more information, contact your local locksmith distributor or Schlage at Web Site: www.schlage.com