How to Correct Straight Screw Marks

Straight Screw Marks on the Ground Surface of a part appear as scratches that go around the diameter of the Finished Part Surface. This condition can occur when speeds, feeds, or the condition of the grinding Wheel are not correct. When Straight Screw Marks are observed on a part it must be scrapped.

PROBABLE CAUSE:
1.
 Grinding Wheel has contamination stuck to it.
2.
 The Diamond Dresser is blunt or damaged and is therefore not dressing the Grinding Wheel correctly.
3.
 Coolant is contaminated.
4.
 Table Slide Speed is too high.
5.
 In-feed increments are too large.
6.
 Work Head Spindle Speed is too low.
7.
 Work Head Spindle Speed is too high.
8.
 Grinding Wheel is worn on one side.
9.
 Grinding Wheel has a sharp edge.
10.
 Grinding Wheel is cracked.

RECOMMENDED ACTION:
1.
 Inspect and dress the Grinding Wheel.
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2.
 Replace the Diamond Dresser.
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3.
 Replace the Coolant Unit Filter Paper.
4.
 Make sure the Table Slide Speed is set correctly. Call USACH Service Department.
5.
 Make sure the In-feed increments are set according to the current break point settings table. If In-feed increments are not set correctly, adjust them.
6.
 Make sure the Work Head Spindle Speed (variables 524 and 525) are set according to the Grinder 500 Variables Table. If the Work Head Spindle Speed is not set correctly, adjust the Work Head Spindle Speed.
7.
 Make sure the Work Head Spindle Speed (variables 524 and 525) are set according to the Grinder 500 Variables Table. If the Work Head Spindle Speed is not set correctly, adjust the Work Head Spindle Speed.
8.
 Inspect and dress the Grinding Wheel.
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9.
 Inspect and dress the Grinding Wheel.
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10.
 Replace the Grinding Wheel.
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