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COMBI thread/depth Gage

COMBI Calibration Master and Depth Calibration Procedure

MPH Power thread gage

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Calibration Master

 Leitech's inch or metric Calibration Masters make it easy to reset the specified calibration length after changing or replacing gaging members on any size COMBI Gage currently manufactured.
1. Dial in the required thread pitch on the Master to establish the specified calibration length.
2. Loosen the two locking set screws (A) on the COMBI Handle.
3. Place the gage in the appropriate size hole in the Master.
4. Turn the NOT GO end in either direction to set the COMBI Gage measuring scale on the sleeve to either the .400 line for the inch model, or the 10,0 mm line on the metric.
5. Re-tighten the locking screws.
Your COMBI Gage is now set at the correct calibration value for accurate functional thread depth measurement. This fast and foolproof method eliminates the need for a vernier caliper, depth micrometer, or gage blocks.
Note: Common size nuts
available from customer inventories are tightened against the removal sleeve (similar to a jam nut) to remove the taperlock member from the Leitech handle.

 

Calibration Procedure

 The gaging members on the Leitech COMBI gage are of a special taperlock design which can be easily changed with a removal sleeve that can be purchased from Leitech U.S. and a nut of the correct size available from customer inventories.
1. Slide the COMBI removal sleeve (
Green for the GO & Red for the NOT GO) over the gage member to be removed.
2. Thread the nut (supplied by the user) on to the gage member, and tighten it against the removal sleeve (similar to a jam nut) until the gage member is pulled loose from the handle.
3. Insert the new thread member and give it a light tap against a soft surface to seat the tapered portion of the gage member in the handle.
4. Loosen the two locking screws "A" on the COMBI handle to permit depth calibration of the measuring sleeve. Now, the user can turn the threaded inner portion of the handle body which extends or retracts the face of the GO gage member in relation to the face of the measuring sleeve. Note: The measuring sleeve is set a few threadsback from the face of the GO member to permit easier entry into the product thread.

5. Place the gage in a Leitech Calibration Master as described on the reverse side. As an alternative, a gage block stack corresponding to the calibration length (X) in the chart below may be used. In this procedure, the face of the measuring sleeve should be resting on the block stack and the face of the GO member should be against a reference plane,such as a surface plate. A depth micrometer or a vernier caliper may be used in a similar fashion.
6. Turn the NOT GO end in either direction and line up the measuring scale on the sleeve with the .400 line on the inch model, or the 10,00 mm line for the metric, at the intersection of the measuring sleeve and the handle body.
7. Re-tighten the locking screws finger tight.
Your COMBI gage is now set at the correct calibration value for accurate functional thread depth measurement. The user can discriminate thread depths to an accuracy of approximately 1/2 division or .012 in. (0,25 mm).

 

Calibration procedure Illustration


These values are calculated by the formula:

Inch calibration length (X) = .400 in. + [.50 x 1/pitch]

Metric calibration length (X) = 10,0 mm. + [.50 x pitch]

This method will provide conformance to FED-H28, Sec. 6A. The crest of the first full thread of all Leitech GO thread members is held to a 0.5 pitch, plus 0 minus .06 pitch tolerance from the front face of the thread member.

INCH and METRIC Pitches and Calibration Legnths for the Leitech COMBI Calibration Master

PITCH

CALIBRATION
LENGTH (X)

PITCH

CALIBRATION
LENGTH (X)

 64  .408 in.  0,00 mm  10,00 mm
 56  .409 in.  0,20 mm  10,10 mm
 48  .410 in.  0,30 mm  10,15 mm
 44  .411 in.  0,40 mm  10,20 mm
 40  .412 in.  0,45 mm  10,22 mm
 36  .414 in.  0,50 mm  10,25 mm
 32  .416 in.  0,60 mm  10,30 mm
 28  .418 in.  0,70 mm  10,35 mm
 24  .421 in.  0,75 mm  10,38 mm
 20  .425 in.  0,80 mm  10,40 mm
 18  .428 in.  0,90 mm  10,45 mm
 16  .431 in.  1,00 mm  10,50 mm
 14  .436 in.  1,25 mm  10,62 mm
 13  .438 in.  1,50 mm  10,75 mm
 12  .442 in.  1,75 mm  10,88 mm
 11  .445 in.  2,00 mm  11,00 mm
 10  .450 in.  2,50 mm  11,25 mm
 9  .456 in.    
 8  .463 in.    

COMBI Removal Sleeves

Leitech U.S. Limited - 908 Sharon Road - Janesville, WI 53546-5220
Phone 608-531-0021 - Fax 608-531-0022