CHASSIS METAL WORK
Weld Slag and Spatter
Weld slag shall be removed before application
of finish, evidence after finishing is cause for rejection.
Weld spatter on a mounting surface is cause
for rejection; permissible on all other surfaces.
Burrs
If present, burrs
shall not exceed the limits of paragraph
Removal of burrs shall comply with the
requirements of the previous paragraph
Corners
Corners shown sharp on a blanked part may be
produced with a radius, chamfer, or break complying with paragraph.
Sheared Edges
A sheared edge shall be square within 10⁰
The extreme edge as illustrated in before
shall be used when measuring to or from the edge.
Squareness
Unless otherwise specified, sheet metal
cabinets, panels, doors, chassis, etc. (over 12" in the smallest
dimension) shall be square within .015 in/ft. not to exceed .12 max.
Squareness to be within dimensional limits.
Squareness of a Right Angle Bend
Unless otherwise specified, 90⁰
forms 1 inch or under in length shall be square within the locating
dimension. Forms beyond 1 inch shall be square within .005 in./in.
of bend length. The long leg is considered to be datum.
Squareness of structures, fabricated by welding or riveting
together sheet metal and or structural pieces shall be square and free
from twist or lean within tolerance.
"U" Forms - Legs of the "U" form shall be
square to the common axis of the two datum holes within .005 in./in.
Squareness is measured radially from the common axis.
Edge Squareness
Between two sheared edges or two formed
sides, the squareness shall be within .015" per linear foot.
Between a sheared edge and a formed side, the squareness shall be within
.020" per linear foot. Dimensional tolerances shall apply if
tighter.
Intersecting Surfaces Shown at 90⁰
Unless otherwise specified, intersecting
surfaces shown at 90⁰ shall be square within the tolerance
on the dimension of the longest surface. The long surface is used
as the datum for checking squareness.
Parallelism
Surfaces
Unless otherwise specified, the parallelism
of surfaces shall be controlled by the tolerance of dimension between
the two surfaces. The longest surface shall be used as datum.
Sheet metal cabinets, panels, doors, chassis,
etc. (over 12 inches in the smallest dimension) shall be flat within .03
in./ft. not to exceed .12 max. At any point flatness variation
shall not exceed .03 in./ft. applied over a smooth curve. Flatness
includes dishing, bow, and twist.
Bend Line Straightness
Unless otherwise specified, bend line shall
be straight within .010 in./ft. not to exceed .06 max. At any
point the straightness variation shall not exceed .010 in./ft. applied
over a smooth curve.
Mounting Plane Flatness
All points on members which form a mounting
surface shall form a true plane surface within the limits. All points
within a 12" x 12" area must form a plane within .016, and 24" x 24"
area must from a plane within .031", and the entire surface must form a
plane within .062".
Grain direction shall be perpendicular to
formed bends unless otherwise specified. This minimizes crazing or
material fracture on bends.
COMPONENT ASSEMBLY
General - Card cages, doors, panels, side
plates, electro-mechanical subassemblies, cabling and
hinge/latch/locking mechanisms shall conform to the requirements
specified herein or as required by referenced paragraph.
Damage
There shall be no damage beyond the limits
specified in applicable sections of this document.
Hardware Assembly Sequence
Acceptable
The sequence of mechanical hardware assembly
conforms to specific product documentation.
Unacceptable
Any deviation from product documentation.
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