MIL-T-62518 Trucks, Maintenance: With 9 To 37 Meters 30 To 120 Foot Multi-Position Aerial Platform, Modified CommercialThis specification covers diesel and gasoline engine driven, four-wheel, two-rear-wheel drive; four-wheel, four-wheel drive; and six-wheel, four-wheel-drive trucks having minimum gross vehicle weights GVW of 6800 kilograms kg 15,000 to 22 700 kg 50,000 pounds, equipped with maintenance bodies and 9 to 37 meters m 30 to 120 foot multi-position, articulating, boom type aerial platforms. Vehicles procured under this specification are commercial items which are warranted by the manufacturer as specified in acquisition documents.

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MIL-T-62518A

*    3.9.1  Welding.  Adequate preparation of metal, prior to welding of the body and aerial tower components, shall be provided.  Surface of parts to be welded shall be free of rust, scale, paint, grease and other foreign matter.  Welding rods (electrodes) shall be compatible with the metal being welded.  All critical arc welds shall be magnaflux or dye penetrant inspected.  The following defects shall not be acceptable:

(a)     Slug or plug welding

(b)    Undersize of fillet welds, overlaps, inadequate fusion and penetration, undercutting of

weldments, and vertical down welding

(c)     Unremoved slag and spatter

(d)    Cracks

(e)     Spot, tack, or intermittent welds for strength.

Weld penetration shall be such as to provide transference of maximum design stress through the base metal juncture.  Intermittent welding shall be permissible when in accordance with 3.9.2 through 3.9.3.

3.9.2  Workmanship specimens.  Workmanship specimens shall be prepared by the manufacturer, for the body and aerial tower components, to simulate all welding conditions.  The specimens shall represent the minimum acceptable weld quality and cleaning procedure to be used in production.  Upon submittal of these specimens by the contractor, the quality level and identification shall be subject to approval by the Government.  The specimens shall be prepared using the welding procedures to be employed in production.  Specimens prepared to represent multiple pass welds shall be made in such a manner as to leave at least two inches of each layer

of weld metal exposed.  Approved specimens shall be retained at the contractor's plant.

3.9.3  Welding procedures.  The welding procedure shall be recorded prior to production of any weldment, but no procedure qualification other than workmanship specimens shall be required.

3.9.4  Factors.  The factors listed below which are applicable shall be included in the recorded welding procedures:

(a)     Joint sketch

(b)    Joint type and preparation

(c)     Base metal type

(d)    Filler metal, size and type

(e)     Position of welding

(f)     Arc-voltage, current range and polarity

(g)    Manual or machine

(h)    Travel speed (machine only) (i)     Pre-heat and post-heat.

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