procedure covers the selection and use of precision
measuring equipment for verification of product
dimensions. Note: If
there is any question at any point about this procedure,
contact the QC Specialist, QC Supervisor, or
Machining Department QC Inspector.
INFO TO USE
WHAT TO DO
||Anyone (typically QC
||As needed to take precision
||Possibly Production Floor
Traveler, Machining Department Inspection
Order, print or inspection sheet
||Determine which measurements are to be taken and,
if appropriate, the frequency with which they are to
be taken and any special sampling or other criteria;
determine the accuracy required for the reading (5%
of the tolerance interval, .003" maximum for
forging, .002" maximum for
||Clear mental picture of the needs of the
measuring task at hand
||After Step 1
||Decision from Step 1; Inspection Order,
Machining Department Inspection Order, print or Part Inspection
Choose the correct measuring
equipment to be used per these
1) Equipment specified by the QC
Forging Supervisor, CMM Programmer/Operator, QC
Specialist, QC Machining Supervisor or Machine
2) Equipment specified on the
Traveler or noted on the Part Inspection Sheet.
3) [Forge Division only] Equipment
chosen per the table below.
|Measuring equipment choice
||After Step 2
||Decision from Step 2
||Obtain the necessary measuring equipment (if do
not already have ready access to needed equipment,
see QC Specialist, QC Forging Supervisor,
Calibrations Clerk, or QC Machining Supervisor;
ensure that equipment has been calibrated/verified
per TOP-CALIB. DO NOT adjust the equipment so as
to invalidate the calibration; when employees own
their own measuring equipment, the selection of
equipment is covered in Step 2
||Needed measuring equipment ready to use;
equipment not adjusted by unauthorized
||Before tool is used to verify
||Decision from Step 1; Inspection Order, Machining
Department Inspection Order, print or Part Inspection
||Record Tool ID Number, Date, and Operator Stamp
on Tool Verification Log Sheet.
||Traceability of tool recorded.
CRITERIA FOR SELECTION OF LINEAR MEASURING
standard-issue 8" digital calipers, unless measuring
a dimension with a tolerance interval of less than
.060" or where the configuration of the part
indicates one of the following.
intervals of less than .060" use a micrometer or a
caliper specifically verified to be accurate to within
1/20 of the tolerance interval.
beyond 8" use longer digital, dial or vernier
For an external
distance perpendicular to a large, flat surface, use a
height gage on a surface plate.
the depth of a depression, use a depth
the thickness of webs, use spring
radii use a radius gage or CMM.
angles use angle plates or CMM.