1、MIL-C-3774B 14 June 91 SUPERSEDING 21 September 62 MIL-C-3774A MILITARY SPECIFICATION CBATES, WOOD; OPEN 12,000- MD 16,000-BOUND CAPACITY This specification is approved for use by all Departments and Agencies of the Department of Defense. E. Scope 1.1 scope,. This specification covers open crates. 1
2、.2 Classification. The crates shall be of the following types and styles, as specified (see 6.2): Type 1 - Nailed (for loads not exceeding 12,000 pounds or sizes not greater than 16 feet in length, 8 feet in width, and 8 feet in height. Style A Skid base, nailed assembly. Style B - Sill base, nailed
3、 assembly. Type I% - Bolted, fully demountable, skid base (or loads not exceeding l6,OOO pounds or sizes not greater than 40 feet in length, 8 feet in width, and 16 feet in height). For further lmitatons based on load and length combinations see Table VI11 and X. 2. APPLICAI3LE DOCUMENTS 2.1 Governm
4、ent documents 2.1.1 .Smxifications and standards. The fo%lowing speciications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifica
5、tions and Standards (DoDISS) and supplement thereto, cited in the solicitation (see 6.2). IBenefictal comments (recommendations, additions, deletions) any pertinent I Idata which may improve this document should be addressed to: I ICommanding Qffie (code l56), Naval Construction Battalion Center, Po
6、rt I IHuenenie, CA 93043-5000, by using the self-addressed Standardization I IDocument Improvement Proposal (DD Form 1426) appearing at the end of this I Idocument or letter. I AMSC N/A PSC 8115 pISTRIBUT1ON STATEMENT A. Approved fol- public release; distribution is un1 imite d. Provided by IHSNot f
7、or ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-3774B SPECIFICATIONS FEDERAL FF-B-561 - Bolts, (Screw) Lag. FF-3-575 - Bolts, Hexagon and Square. FF-B-584 - Bolts, Square Neck and Tee Head FF-N-105 - Nails, Brads, Staples and Spikes; Wire, Cut and Wrought. FF-N-83
8、6 - Nut: Square, Hexagon, Cap, Slotted, Castle, Knurled, NN-P-530 - Plywood, Flat Panel Welding and Single Ball Seat. STANDARD MI LI TARY MIL-STD-105 - Sampling Procedures and Tables for Inspection by MIL-STD-129 - Marking for Shipment and Storage. MIL-STD-731 - Quality o Wood Members for Containers
9、 and Pallets. MIL-STD-1186 - Cushioning, Anchoring, Bracing, Blocking and Waterproofing; with Appropriate Test Methods Attributes, (Unless otherwise indicated, copies of federal and military specifications, standards, and handbooks are available from the Standardization Document Order Desk, Bldg. 40
10、, 700 Robbins Avenue, Philadelphia, PA 19111-5094.) 2.2 Other Government documents, drawings and publications. The following other Government documents, drawings, and publications form a part of this specification to the extent specified herein. Unless otherwise specified, the issues are those cited
11、 in the solicitation (see 6.2). ASTM ASTM D 3953 - Standard Specification for Strapping Flat Steel and ASTM D 4442 - Standard Test Methods for Direct Moisture Content of ASTM D 4444 - Standard Test Methods for Using and Calibration of Seals Wood and TJood-Base Materials Hand-Held Moisture Meters (Ap
12、plication for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.) NATIONAL MOTOR FREIGHT TRAFFIC ASSOCIATION, INC., AGENT National Motor Freight Classification (Application for copies should be addressed to the American Trucking As
13、sociation, Inc., Traffic Department, 1616 E Street, N.W., Washington, DC 20036. ) 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Uniform Freight Classification (Application for copies should be addressed to the Uniform Classification Committee, Ta
14、ri% Publishing Officer, Room 1106, 222 South Riverside Plaza, Chicago, 1% 60606.) (Non-Government standards and other publications are normally available fom the organizations that prepare or distribute the documents. These documents also may be available in OE through libraries or other information
15、al services.) 2.3 Order of precedenee. In the event of a conflict between the text o this specification and the references cited herein (except for related associated detailed specifications, sheets OK MS standards), the text of this specification shall take precedence. Nothing in this specification
16、, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 preproduction p-ack. When specified (see 4.3 and 6.2) the contractor shall furnish a preproduction pack for examination and test within the time frame specified (see 6.2) eo prove
17、 prior to starting production packaging, that the applied preservation, packaging, packing, and marking comply with the requirements of this specification. Examination and test shall be as specified in section 4 and shall be subject to surveillance and approval by the government (see 6.3). -3.2 Mate
18、rials,. Material shall be as specified herein and in applicable speci%ications and standards, and other referenced documents. Materials not specified shall be selected by the contractor and shall be subject to all the provisions of this specification. Materials shall be free of defects which adverse
19、ly affect performance or serviceability of the finished product (see 6.4). 3.2.1 New materials. procedures are encouraged and recommended and shall be permitted under conditions specified herein, provided the are equal or better than the specified materials OK procedures. The use of newly developed
20、packaging materials OK 3.2.2 Safety. Materials used for the crates shall present no environment or toxicological hazards as defined by current industry standards federal or state lav7s or regulations. OK applicable 3.2.2 Lumber. Wood members shall be selected from the WOO groups listed in and shall
21、conform to the requirements of MIL-STB-731 as follows: Class 1 - All load-bearing floorboards, Skids and all framing members. Class 3 All rubbing strips and non-load-bearing floorboards. Unless otherwise specified herein, the nominal sizes as specified in MIL-STD-731, Table 1 shall be the minimum ac
22、ceptable sizes for lumber components. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-C-3774B AL 0 9999986 8484682 T E MIE-C-3774B 3.2.2 ,pP:rc.ood. Unless otherwise specified (see 6.2), plymod shall conform to NN-P-530, type EI, class E or 2.
23、 3.2.3 Nails and staples. Nails and staples shall be steel. and shall conform FF-N- 105. 3.2.4 Bolts and nuts. Bolts shall conform to FF-575, FF-B-584, and FF-N-836, type and style as applicable. 3.2.5 Lag bolts. Lag bolts shall conform to FF-B-561, Type and grade as applicable. 3.2.6 bletal strappi
24、ng. Strapping used to reinforce crates shall conform to ASTM D 3953 Type 1, 2, or 3 as applicable. Strapping finish shall be as specified herein. 3.3 Construction. (for definitions see 6.8). 3.3.1 mon. The following rules shall be followed to determine the size, placement, and quantity of nails for
25、fabrication and assembly of the crates when not specifically covered in detailed requirements. 3.3.1.1 ?lai$ types. All nails, that are not clinched shall be cement coated or etched (see 6.9). Nails used for assembly (nailing of side, end, top and base panels to form the crate) shall be cenent-coate
26、d esuntersunk head (sinkers), cement-coated standard (coolers), cement-coated countersunk railroad (corkers) , or common. 3.3.1.2 Fastening methods. Nails shall be driven through the thinner into the thicker member whenever possible. +Then the flat faces of two pieces of lumber, whose combined thick
27、ness is 3 inches or less, are nailed together, nails used shall be long enough to pass through both pieces and shall be clinched not less than l/4 inch. Unless otherwise specified (see 6.2), nails shall not be clinched when the combined thickness of two pieces is more than 3 inches or when the flat
28、face of one or more pieces is nailed to the edge of another. Unclinshed nails skialP be as %mg as practicable without splitting the niatesrial However, that portion of the nail in the thicker piece shall be not less than two times the length of the wail in the thinner piece %OK tenpenny nails and sm
29、aller, and not less than l 1/2 inches far twelvepenny nails and larger. 3.3.1.3 -. The pattern to be used for the fabrication nailing (fastening together of wood pasts to farm panels) of two flat pieces of lumber shall foll the patterns shown in figure l. Nailing sf members to the edges of specified
30、 herein. Nail sizes designated in table VI1 for assembly of crates are based on group E and 1% woods. When group I% and IV woods are used, nail sizes shall be not more than onepenny size smaller than those specified. other member shall conform es details ShoPm in figure l when not otherwise 3.3.2 ,L
31、ag bolt apglication. The portion of the lead hole for the shank of the lag bolt shall be the same diameter as the shank. %he portin of the lead hole for threads of lag bolts shall be as shown in table E. 3.3.3 polt application. Countersinking o% bolts shall not be permitted. Moles shall be prebored
32、to receive bolts and shall be the exact diameter of the 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-3774B AL 9999906 0484683 E MIL-C-3774B bolt shank. A flat washer shall be used-undar the head and nut of each machine bolt and under the n
33、ut of each carriage bolt and step bolt. 3.3.4 .Spslieinq. Splices and butt joints in frame members and sk%ds of long crates shall be as shown in figure 2. TABLE 1. Lead holes for lag bolts I Diameter of lead hole Diameter of threaded portTon o% lag bolt Inch l/4 5/16 3/8 l/2 5/8 3/4 Group a, 11, and
34、 I I I Inch I I 3/16 I I I 1/4 I l/4 I I l/4 I I 3/8 I 3/8 I 3/8 I 1/2 I %/a I 5/8 I11 woods l GKOUP IV woods. Inch 3/16 5/16 I I 3.3.5 Clearance. A minimum clearance of l inch shall be provided between the contents and the inner surfaces of the sides, ends, and top of all crates. 3.4 .Tvpe I, naile
35、d crates,. The dimensions of the crates shall be as specified (see 6.2) but shall not exceed the riiaximum dimensions specified in 1.2 fole type 1 crates. 3.4.1 skid base (style A). The skid base shall be constructed of longitudinal skids fleamid with crossnienibers. figures 3 or 4, as applicable, a
36、nd as specified herein. Variations in skid bases for h%gh, nalpro crates (when height is three or more time greater than width) shall be as shovm in figure 4 and as specified in 3.4.1.5. Construction shall be as shovm in 3.4.1.1 Skids Any species of wood except group 1 shall. be used for skids. Skid
37、s shall be spaced no frther apart than 48 inches, center to center, across the width of the skid base. 1.Jhere a heavy concentrated load is invobved, intermediate skids may be placed closer together under the points of load concentration. The minimum sizes in table %I shall be followed, and when eit
38、her the crate length OK net load exceeds the maximum shown, the next larger skid shall be used. The 2- by 4- and 3- by 3-inch skids shall be used in one piece without splices. TABLE II. Skid sizes - I Maximum length I .axiniUm net load I of crate I Size o sleids. Inches 2x4 3x3 4 x 4 Feet: I 12 I 12
39、 I 16 I 16 1 gounas I 500 I 2,000 I l0,000 I %2,00Q I 4 x 6(on edge) I I 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-3774B BL 9999906 84B4bf34 3 MIL-C-3774B 3.4.1.2 Rubbing stris. Rubbing strips shall be used on each skid, and shall be ma
40、de of 2-inch-thick lumber, and be approximately the same width as the slcid. Rubbing strips shall be attached to the skid with two rows of twelvepenny nails staggered and spaced 12 inches apart in each row. The strips shall be beveled full depth at an angle of 45 degrees, and provisions shall be nad
41、e at each end for sling handling and at the center of balance for forklift handling (see figure 3). 3.4.1.3 End headers. The end headers shall be located as shown in figures 3 The sizes of end and 4 and shall be bolted to each skid with one carriage bolt. headers and bolts are outlined as Eollows: S
42、kid size Header size Bolt diameter ( inche a ) (inches) (inch) 2x4 2x4 3/8 3x3 3x3 3/8 4x4 4x4 1/2 4 x 6 (on edge) 4x4 l/2 3.4.1.4 Load-bearing floorboards. Load-bearing floorboards shall be placed where the concentrated loads occur. The cross section for various spans shall be specified in table X.
43、 The end floorboards of 2-inch flooring may be considered as load-bearing within limits of their assigned values. The load-bearing members chai% be placed with the ends flush with the outside faces of the skids, as shown in figures 3 and 4, and bolted to each skid with carriage bolts. One bolt shall
44、 be used at each skid crossing for widths not exceeding 4 inches and two bolts, for greater widths. The size of carriage bolts shall be the same as those used in the end headers. 3.4.1.5 Forklift area flooring. The reinforcement of the base for forklift handling at the ends shall consist of one of t
45、he following, as specified (see 6.2). (a) Forklift headers spaced 20 and 40 inches from each header (b) 2-inch-thick boards extending 42 inches from each end. (c) Plywood for narrow crates. Forklift headers shall. be the same size as the end headers. The forlclift headers shall be placed and bolted
46、to the skids, including intermediate skids, as shovm in figure 3. 3 and 4) shall consist of 2-inch boards and shall be bolted to the outer skids with 3/8-inch carriage bolts. shall be fastened to the center skids with nails as speciied in 3.3.1 and as shown in figure 1. For high, narrow crates (when
47、 height is three or more times the width) the base as shovm in igure 4 shall be used. Plywood-sheathed bases shall be used 7hen high, narrow crates are 30 inches or less in width. The l/2-ineh p$ywood shall cover the entire base and shall be nailed to the skids as shown in figure 4. The flooring cov
48、ering 42 inches of each end (see figures When intermediate skids are used, the boards 3.4.1.4 Piaaona1s - Diagonals l by 6 inches in size shall be used between forklift areas and load-bearing floorboards, or between floorboards, and shall be nailed to the skids and to each other at the point of inte
49、rsection. When intermediate skids are used, the diagonals shall be nailed to the intermediate skid. Nailing shall be as specified in 3.3.1 and as shown in figure l. O 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-3774B BE M 9979706 0484685 5 MIL-C-3774B Diagonals shall be placed in an X pattern as close to a 45 degrees as possible, except 7hen the crate width is one and
