Marks USA Classroom Intruder Series Locks

Teachers can lock or unlock their classroom doors from the inside for added safety in an emergency.

Note: The levers come pre-assembled in the box. The interior rose is separate to insure proper assembly.

  1. Remove the inside lever by inserting the key and rotating the plug a quarter turn. Depress the lever catch.
  2. With the lever catch depressed, pull the lever off the lockset.
  3. Carefully remove the inside rose assembly.
  4. Install the latch into the mount. Secure using the two Phillips head screws.
  5. Slide the lock housing into the cross bore opening, making sure the thru bolts (rose posts) slide into the openings. The retractor must engage the latch tail, and the latch prongs engage the inside lock housing. Check to make sure the latch retracts.
  6. Slide the inside rose assembly onto the spindle. Secure using the two Phillips head screws.
  7. Install the rose cover onto the inside rose assembly. The notch in the rose cover must align with either the notch at the 3 o'clock or 9 o'clock positions in order for the cover hole to align with the lever catch.

IMPORTANT: When completing the following steps, be sure the key is removed from the outside lock cylinder.

  1. Insert a Phillips screwdriver into the inside key cam slot and turn counterclockwise as far as possible. This times the inside mechanism with the outside lock cylinder mechanism.
  2. Insert the key into the inside lever lock cylinder.
  3. Rotate the key approximately one-quarter turn counterclockwise.
  4. Slide the inside lever onto the lever tube. The lever should click into place as the lever catch latches. Test the operation of the outside and inside levers using a key to be certain they are properly timed.

Using the key in the outside lever should engage and disengage the outside lever. Using the key in the inside lever should also engage and disengage the outside lever. If not, repeat steps eight through 11.

The Intruder Function cylindrical locksets accept many other original equipment standard, high security and interchangeable core cylinders using the Marks adapter tailpieces. The Grade 1 factory standard is the Marks "C" keyway six-pin lock cylinder. The Intruder Function cylindrical locksets are available in six- or seven-pin interchangeable core models for Best™, Corbin/Russwin, Keymark™, Schlage, and Yale.

The Intruder Function latch bolt and deadbolt mortise locks are handed. The handing is field changeable without requiring any additional parts.

Marks USA Classroom Intruder Function cylindrical locksets and mortise locks have a lifetime mechanical limited warranty.

For more information, contact your local locksmith wholesaler or Marks USA, 5300 New Horizons Blvd, Amityville, NY 11701. Telephone: 631-225-5400 or 800-526-0233. Fax: 631-225-6136. Web site:

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