Electronics Inc. • (574) 256-5001 • www.electronics-inc.com
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Ball Plane Flatness Check
This is a pass/fail test. Place a qualified flat surface, such as a step block or the flat check block, on the gage head to
determine if one of the balls is lower than the other three balls. Check if the gap is larger than ±.002 inch by
attempting to insert a .002 inch (0.05 mm) feeler gage between any one of the four balls and the flat surface. If the
feeler gage can be inserted between any ball and the flat surface while the remaining three balls are in contact
with the flat surface, the ball plane flatness exceeds the tolerance and the gage head must be replaced. Record
“Pass” or “Fail” in the column of the form. Use the Notes column to record any repairs or replacements.
A .002 inch feeler gage verifies that the ball plane flatness is within tolerance
As Found
The “As Found” readings are the initial observations of the gage. These are made before any adjustments are made
(including any adjustments to the Spindle Starting Position) and entered into the appropriate cell on the
Certification form. If no adjustments are made, these values are then copied into the “As Returned” columns of the
form. Note: If adjustments are made, the new value must be within tolerance allowed and entered into the “As
Returned” section. If adjustments cannot bring the gage reading into the allowed tolerance, the gage must be
returned for repair to Electronics Inc.
As Found Bezel Spindle Starting Position
Place a flat check block onto the gage and determine the Spindle Starting Position. Do not rotate the bezel (rim of
indicator) on the gage until all of the “As Found” readings are taken. The bezel synchronizes the spindle to the dial
face readings. If the bezel zero alignment is near either end of travel of the spindle, the readings may not be
accurate. The most accurate readings are achieved when the spindle center position is aligned with the bezel zero.
Take the “As Found” readings first then check the actual alignment of the bezel. If no adjustments are required,
the “As Found” readings will be copied to the “As Returned” column. If the bezel needs correction, the additional
step block readings will be required and recorded in the “As Returned” column.
Step Block Readings
The accuracy of the dial indicator is not stated in SAE AMS-S-13165 but is a requirement of Electronics
Incorporated. Step blocks confirm the indicator accuracy of ±.001 inch over the expected range of travel of 0 to
+.0240 inch.
Place each of the five (5) step blocks on the Almen gage head in the following sequence: Place the step block to
one side, allowing the indicator tip to touch the flat zero reference surface of the step block (not the recessed
step). Loosen the threaded thumbscrew on the bottom left side and rotate the indicator face to align the “0” with
the needle. Tighten thumb screw when completed.
