REV:04/15/09
SCOPE: This
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.
| STEP |
WHO
|
WHEN
|
INFO TO USE
|
WHAT TO DO
|
RESULTS
|
| 1 |
Anyone (typically QC
Inspector) |
As needed to take precision
measurements |
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
machining) |
Clear mental picture of the needs of the
measuring task at hand |
| 2 |
Anyone |
After Step 1 |
Decision from Step 1; Inspection Order,
Machining Department Inspection Order, print or Part Inspection
Sheet |
Choose the correct measuring
equipment to be used per these
criteria:
1) Equipment specified by the QC
Forging Supervisor, CMM Programmer/Operator, QC
Specialist, QC Machining Supervisor or Machine
Operator.
2) Equipment specified on the
Traveler or noted on the Part Inspection Sheet.
Machining Department
3) [Forge Division only] Equipment
chosen per the table below.
|
Measuring equipment choice |
| 3 |
Anyone |
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
personnel |
| 4 |
Anyone |
Before tool is used to verify
dimension |
Decision from Step 1; Inspection Order, Machining
Department Inspection Order, print or Part Inspection
Sheet |
Record Tool ID Number, Date, and Operator Stamp
on Tool Verification Log Sheet. |
Traceability of tool recorded. |
CRITERIA FOR SELECTION OF LINEAR MEASURING
EQUIPMENT
Typically use
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.
For tolerance
intervals of less than .060" use a micrometer or a
caliper specifically verified to be accurate to within
1/20 of the tolerance interval.
For dimensions
beyond 8" use longer digital, dial or vernier
calipers.
For an external
distance perpendicular to a large, flat surface, use a
height gage on a surface plate.
For measuring
the depth of a depression, use a depth
micrometer.
For measuring
the thickness of webs, use spring
calipers.
For measuring
radii use a radius gage or CMM.
For measuring
angles use angle plates or CMM.
|