TOP-MSURE

Trinity Operating Procedures - TOPs

TOP-MSURE: Selection & Use of Measuring Equipment

Rev: 06/29/2021

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.

Procedure:

STEP WHO WHEN INFO TO USE WHAT TO DO

1 Anyone (typically QC Inspector) As needed to take precision measurements Possibly Traveler, Machining Department Inspection Order print or Part 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)

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 Forging QC Supervisor, CMM Programmer/Operator, QC Specialist, Machining QC Supervisor or Machine Operator.

2) Equipment specified on the Traveler or noted on the Part Inspection Sheet. Measuring equipment stated on the Part Inspection Sheet cannot be changed without approval from the QC Mgr/QC Supervisor or Production Supervisor. Accuracy of the new measuring equipment must be equal to or better than the original stated equipment. Machinig Department

3) [Forge Division only] Equipment chosen per the table below.

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, Forging QC Supervisor, Calibrations Clerk, or Machining QC 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

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 Measuring Instrument Verification Log .

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.

Revision history:

Release Date	Description of Change	Owner	Approver
12/06/2017	Updated to comply with revised Quality Manual and new TOPs format.	Tim Ellis	Todd Sheppard
06/29/2021	Updated to add notes on step 2 in "what to do" column.	Dustin Jump	Todd Sheppard

Documents are controlled only when viewed on-line at trinityforge.com in the original English -- printed copies or translations are not controlled documents.
? Trinity Forge & Machine

STEP	WHO	WHEN	INFO TO USE	WHAT TO DO
1	Anyone (typically QC Inspector)	As needed to take precision measurements	Possibly Traveler, Machining Department Inspection Order print or Part 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)
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 Forging QC Supervisor, CMM Programmer/Operator, QC Specialist, Machining QC Supervisor or Machine Operator. 2) Equipment specified on the Traveler or noted on the Part Inspection Sheet. Measuring equipment stated on the Part Inspection Sheet cannot be changed without approval from the QC Mgr/QC Supervisor or Production Supervisor. Accuracy of the new measuring equipment must be equal to or better than the original stated equipment. Machinig Department 3) [Forge Division only] Equipment chosen per the table below.
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, Forging QC Supervisor, Calibrations Clerk, or Machining QC 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
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 Measuring Instrument Verification Log .