specified in paragraph (b) (2) of this section.

(3) Where apartment buildings are equipped with self-closing, automatically-locking street entrance doors, access for delivery employees must be provided by an attendant, an electromechanical door lock system, or a key retaining box within convenient reach of the door. Both devices must incorporate an Arrow lock; to activate the electromechanical door lock, or for safekeeping of the building entrance door key.

(4) When new apartments are being erected or existing ones are remodeled, postmasters will inform buildings and owners of the requirements of the regulations in this part and will provide for a suitable inspection to see that approved receptacles of safe and durable construction are installed in conformity with the regulations in this part.

(5) Individuals or firms interested in the manufacture of apartment house mailboxes must submit to the Bureau of Operations for approval the following:

(i) Vertical style. A three-gang unit complete with individual door locks and provision for an Arrow lock in the master door.

(ii) Horizontal style. A four-gang unit (two over two) with locks as above. If rear-loaded, a door or screen on back of boxes is not necessary.

(b) Scope and classification—(1) Scope. This standard establishes the procedures for testing and accepting apartment house mail receptacles. The use of this standard is mandatory and boxes submitted which do not conform in all respects to this standard will not be considered for approval by the Postmaster General.

(2) Classification. This standard covers apartment house mail receptacles of the following types, as specified:

(1) Type I. Vertical. A minimum three-gang unit complete with individual door locks and provisions for an Arrow lock in the master door. The maximum number of boxes which may be installed under one Arrow lock is 10; the minimum number is three.

(ii) Type II. Horizontal. A front or rear loading, four-gang unit (two over two) with individual door locks. The front loading units shall have provisions for an Arrow lock in the master door.

(c) Applicable documents—(1) Specifications and standards. The following

documents of the latest issue form a part of this standard:

(i) Specifications.

Military:

MIL-T-704-Treatment and Painting of

Material.

(ii) Standards.

Federal:

Federal Test Method Standard 141, Method 6191.

Federal Test Method Standard 406, Method 2021.

(Activities outside the Federal Government may obtain copies of Federal Specifications, Standards, and Handbooks as outlined under General Information in the Index of Federal Specification, Standards, and Handbooks and at the prices indicated in the Index. The Index which includes cumulative monthly supplements as issued, is for sale on a subscription basis by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. Single copies are available without charge at the General Services Administration regional offices in Boston, New York, Atlanta, Chicago, Kansas City, Mo., Dallas, Denver, San Francisco, Los Angeles, Seattle, and Washington, D.C.)

(2) Other publications. The following publications of the latest issue form a part of this standard:

AMERICAN WELDING SOCIETY Recommended Practice C1.1.

Recommended Practice for Resistance Welding.

(Copies of American Welding Society publications may be obtained from the Society at 345 East 47th Street, New York, N.Y. 10118.)

Materials.

(d) Requirements—(1) Latitude will be allowed in the material used. Materials must be compatible with each other; nontoxic and nonirritating to humans. Dissimilar metals shall be protected against galvanic corrosion. The material used in the fabrication of this equipment shall be new, suitable for the purpose used, free of all defects and the best commercial quality for this type of equipment.

(2) Receptacle doors. (i) The doors shall be designed to operate freely without binding or excessive play. The doors shall, once opened, remain in the opened position until the patron pushes it in the closed position. The doors of vertical type receptacles shall have a 90° flanged edge of a minimum one-quarter inch on the

side, slightly less on top and bottom. If extruded aluminum doors are used, they shall provide strength and stiffness on the edge opposite the hinge side equivalent to the sectional modules of a quarter-inch bar. The fitting of the door into its frame shall be of such tolerances to preclude prying with thin instruments. The surface of the doors shall be unbroken with the exceptions as described in subparagraph (5) of this paragraph.

(ii) The dimensions of the clear opening of the door frame of each horizontal type receptacle shall be identical to the cross-section measurements of

receptacle itself.

the

(3) Master door. (i) The master door and frame shall be designed to operate freely without binding or excessive play. When the master door is in a minimum 90° open position, all individual boxes of front loading receptacles shall be accessible for deposit of mail by the carrier. All horizontal-type front loading receptacles shall have solid backs. The master door for both vertical-type and front loading horizontal-type receptacles shall remain in the open position while the carrier is depositing mail. The master door shall be formed to accommodate an inside Arrow lock furnished by the local postmaster for use by letter carriers. The key shall be in custody of postal employees. The master door shall be accurately assembled using jigs or fixtures to assure flatness and proper alignment for operation. The door shall be rigid, square, and true.

(ii) The master door frame for vertical-type receptacles shall be attached to the cabinet with either permanently affixed and side-mounted pivots, a suitable bottom-mounted full-length hinge or any other means which will preclude either cabinet from being easily removed from the master frame and which will pass the tests to be conducted by the Postal Engineering Test Laboratory.

(iii) The master door frame for horizontal-type receptacles shall be attached to the cabinet with full-length side-mounted hinge or any other device which offers equal or better security. The master door shall not be wider than 30 inches.

(4) Locking provisions. (i) Each receptacle door shall be secured by a fivepin tumbler cylinder lock with a minimum of 250 key changes. The locks must be securely fastened to the door. If locks are mounted on a backing plate, the plates shall be constructed of hardened

steel of proper design and thickness to preclude punching out of locks. Effective July 1, 1970, if the lock extends more than 5% inch on the inside of a vertical type box, a deflector shall be provided over the lock barrel for the easy deposit of mail.

(ii) Each lock shall be clearly numbered on the back. The lock number shall also be clearly shown on the inside of the master door directly above the individual box to which it is attached.

(iii) The master lock shall be attached to the master door by the postmaster's representative.

(5) Numbers and name cards. (i) Vertical-type receptacles shall be numbered or lettered in numerical or alphabetical sequence from left to right. Horizontal-type receptacles shall be numbered or lettered in sequence from top to bottom.

(ii) Each receptacle shall be equipped with a clasp or holder to accommodate a name card for identifying the patron or patrons using that box. The holder or clasp shall be located on the frame above each receptacle or inside at the rear of the box where the patron's name will be easily visible to the carrier when the master door is open. The holder shall be of sufficient size to hold a name card of a minimum 34 x 21⁄2 inches in verticaltype installation and in horizontal-type installation, as large as space permits. The use of permanent type pressure sensitive labels is permissible.

(6) Capacity. Both horizontal- and vertical-type receptacles must be of sufficient capacity to receive long-letter mail 41⁄2 inches in width and certain large and bulky magazines, unrolled as well as rolled, and must be so constructed and of such height or length and capacity that magazines 141⁄2 inches in length and 31⁄2 inches in diameter, if rolled, may be deposited and removed with facility.

(7) Color. Color of the receptacles is, in general, optional with the manufacturer. Colors and color schemes shall, however, be aesthetically pleasing, dignified and shall reflect good taste.

(8) Finish. (i) Treatment and Painting of Material shall comply with MIL-T704. Choice of materials for coating the interior and exterior of the receptacles is optional, provided all requirements of this standard are met. Finishes shall be compatible with the box materials. All metal parts not inherently corrosion resistant or otherwise treated to be cor

rosion resistant shall be cleaned, treated, and painted.

(ii) All parts to be painted shall be first buffed or sanded, if rust and other encrustation are present. The parts to be painted shall be thoroughly cleaned. Primer and enamel used shall be applied in such a manner as to provide a surface of high quality appearance free from runs, sags, cracks, flaking, peeling, blushing, orange peel effects, or other defects which may affect the drying characteristics, durability, and appearance of the painted surfaces.

(iii) Unless otherwise specified, primer and enamel may be applied by brushing, spraying, or dipping. Each application of primer and enamel shall be permitted to dry thoroughly before applying the succeeding coat.

(9) Marking. Marking of the boxes is optional. Manufacturers are authorized to place on each installation of apartment house mail receptacles the words "U.S. Mail" and a warning notice of the U.S. Penal Code's provisions of law. When the items submitted for approval have been approved by the Post Office Department, manufacturers are authorized to place inconspicuously on each installation their name and words "Approved by the Postmaster General".

(e) Installation provisions. All apartment house mail receptacle units shall be provided with the means for convenient installation.

(1) Instructions. A complete set of instructions for assembling and mounting the receptacles shall be provided with each unit of receptacles. The instruction sheet shall carry a notice that the receptacles meet all requirements of the Post Office Department.

(2) Workmanship. Workmanship shall be of the highest quality throughout in accordance with the best commercial practice for this type of equipment.

(i) Metal fabrications. The metal used in the fabrication of the equipment shall be free from kinks and sharp bends. The straightening of metal shall be done by methods that will not cause injury to the material. Shearing or cutting shall be done neatly and accurately. Corners shall be square and true. All bends of a major character shall be made with metal dies or fixtures, in order to assure uniformity of size and shape. Precautions shall be taken to avoid overheating and heated metal shall be allowed to cool slowly. Burrs, sharp corners and sharp edges shall be removed. All joints shall be

smoothly made and all exposed corners and edges shall be rounded.

(ii) Bolted connections. Bolted connections shall be accurately punched or drilled and shall have the burrs removed. Washers, lockwashers, self-locking nuts shall be used as specified on the applicable drawings. All bolts, nuts, and screws shall be tight. Sheet metal screws shall not be used. Machine bolts may be used where access to nuts would not be possible and where unbolting may be required in which case a sufficient thickness of metal shall be utilized to assure that several bolt threads are engaged. Machine bolts shall be securely held in place by proper lock washers.

(iii) Riveted connections. Rivet holes shall be accurately punched or drilled and shall have the burrs removed. Rivets shall be driven with pressure tools and shall completely fill the holes. Rivet heads shall be full, neatly made, concentric with the rivet holes, and in full contact with the surface of the member. Hollow-type rivets are not acceptable.

(iv) Welding. Welding shall be performed in accordance with applicable American Welding Society recommended practices and by a welder qualified under the referenced welding code. The surfaces of parts to be welded shall be free from rust, scale, paint, grease, and other foreign matter. Welds shall develop full strength in the parts connected. Welds shall be free from skips, blow-through holes, burred areas, excess metal, slag, incomplete fusion, cracks, gas pockets, residual stresses, incomplete penetration, undercutting, flash and spatter metal, electrode skids, excessive indentation, melted base metal, and undersized nuggets. Spotwelding shall be done in closecenters to ensure maximum strength and rigidity and to prevent buckling.

(v) Fabrication and assembly. All components and parts shall be fabricated and assembled to be permanently square, true, and rigid to preclude binding, warping, or misalignment which may reduce or prevent proper equipment operation or maintenance or may result in premature failure of any part or component.

(f) Quality assurance provisions(1) Requirements for approval. (i) Manufacturers of vertical-type receptacles shall submit two ten-gang units. Manufacturers of horizontal-type receptacles shall submit two four-gang units of each type: front loading and rear loading. Each unit shall be made of the exact materials, construction, coatings,

paint, etc., to be identical in every way with the boxes intended to be marketed. One of the boxes will be subjected to destructive testing. All parts of the boxes shall be identified by material, alloy, heat treatment, and (for nonmetallic parts) physical properties. The complete composition, formula, trade name, and designation of all paints and nonmetallics shall be specified.

(ii) The manufacturer shall also submit a copy of the instructions required by paragraph (e)(1) of this section and color samples showing all color schemes expected to be used. Receptacles must be submitted in the packaging proposed for shipping them.

(iii) Written notification of approval or disapproval, including reasons for disapproval, will be issued. All boxes submitted will be returned, including those damaged during testing.

(2) Test methods. The units shall be tested as specified herein. All units which fail to pass all tests shall be rejected.

(i) Capacity requirements. Conformance to paragraph (d) (6) of this section shall be tested by inserting a metal cylinder, 31⁄2 inch diameter by 141⁄2 inches long. The cylinder must be easily inserted and removed. The individual receptacle which has provisions for an Arrow lock shall be taken as an exception.

(ii) Operational requirements. Receptacle doors and master doors shall be capable of operating 10,000 normal operating cycles without breakage of parts and without failure to operate correctly and positively.

(iii) Doors. The doors shall be tested with a Tinius-Olsen tensile/compression testing machine. Resistance to prying shall be such that a force of not less than 35 pounds is required to deflect the unsupported corner of the door outward by 1 inch. The door shall be capable of withstanding 0.4 inch of deflection at that point without serious permanent deformation of more than 0.015 inch. (Effective July 1, 1970.)

(iv) Locks. A minimum of 8 footpounds of force shall be required to punch out the lock. (Two pound weight dropped 4 feet.) If the lock is slowly pushed inward, a minimum of 70 pounds of force shall be required. (Effective July 1, 1970.)

(v) Master door. Master doors shall be tested with a Tinius-Olsen tensile/ compression testing machine. A minimum stiffness for the master door when

pulled outward to simulate the effects of prying at an unsupported corner shall be 50 pounds per inch. The master door frame and assembly shall be able to withstand 0.4 inch of deflection at the corner without permanent deformation of more than 0.015 inch. (Effective July 1, 1970.)

(vi) Impact requirements. The boxes and any coatings applied to them shall not be cracked, chipped, broken, dented (more than one-sixteenth inch in depth), or visibly permanently deformed by a hard steel 2-pound ball with a 2-inch spherical radius dropped 2 feet onto any part of the top and sides of the door.

1

(vii) Coating abrasion resistance. The coating of all boxes formed from ferrous metal or other material subject to corrosion shall meet the abrasive sand test specified herein. Boxes formed from corrosion-resistant alloys of aluminum, stainless steel, and other corrosionresistant materials which are not painted or otherwise coated with a material subject to corrosion are exempt from this test. The test shall be conducted in accordance with Federal Test Method Standard 141, Method 6191.

(viii) Flammability. All boxes shall conform to local building codes. A flammability test shall be conducted on all plastic parts of all boxes. The test shall be conducted in accordance with Method 2021 of Federal Test Method Standard 406. The boxes shall be nonburning or self-extinguishing by this test.

(ix) Ambient conditions. The boxes shall operate properly under the following ambient conditions: Temperatures of 32° to 110° F.

(g) Preparation for delivery—(1) Packaging. The packaged unit and accessories shall be adequately packaged to withstand normal commercial shipping without damage to the unit. Sufficient wrapping, padding, blocking, and bracing shall be used to prevent damage to the box during shipment. The packaged unit and accessories must be capable of being dropped from a height of 3 feet six times (striking once on each of the six faces of the carton) without damage to the box or accessories.

(h) Installation—(1) Location and arrangement. (i) Receptacles in apart

1 "Corrosion," as used in this Standard, means any form of property change due to ambient conditions which seriously detracts from the appearance of the boxes, such as rust, obvious color changes, perforation, accelerated erosion, and disintegration.