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How to Indicate a Vise True
Guide · Updated October 27, 2026
If the fixed vise jaw isn't parallel to the table travel, every cut along X comes out tapered relative to the part edge. Indicating the vise takes five minutes and saves scrap.
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Step by step
- Snug the vise: Leave the bolts snug but movable.
- Mount the indicator: Mount a test indicator in the spindle and bring it against the fixed jaw.
- Sweep: Traverse X along the jaw and note the reading at each end.
- Tap it in: Tap the high end with a dead-blow hammer, pivoting about the other end, until the reading is within 0.0005 in or better.
- Tighten and re-check: Tighten both bolts in stages and sweep again.
Tips
- Indicate the jaw itself, not the vise body.
- Check the jaw top or a parallel with an indicator too.
- Mount the indicator rigidly. See magnetic base setup.
Related: magnetic base setup, parallels.
Quick shop check
Sweep the fixed jaw across 6 in. If the indicator moves 0.004 in, tap the vise end toward the reading, then sweep again. Most shops aim for 0.0005 in or better over the jaw length. Snug one bolt first as a pivot, adjust the other end, then torque both bolts and recheck because tightening often moves it 0.0002–0.0005 in.
Worked example: truing a vise across 6 in
Mount a test indicator in the spindle and set the stylus against the clean fixed jaw. Jog the table so the stylus travels about 6 in along the jaw. If the reading goes from 0 to +0.002 in, leave one hold-down bolt snug, tap the high end of the vise lightly with a dead-blow mallet toward the low side, and sweep again. Repeat until the total change is within the job tolerance, such as 0.0005 in or less, then tighten both bolts evenly and sweep once more, since tightening can move the vise.
FAQ
How close should the vise be indicated?
Within 0.0005 in over the jaw length for general work, tighter for precision work.
Why does it move when I tighten it?
Tighten in stages, alternating bolts, then re-check.
Should I indicate every time?
After any move, and periodically after crashes.
What indicator?
A test indicator. Check it on gage blocks. Build any reference size free with the Gage Block Calculator at gageblockcalc.com.
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General shop information only — follow your gage manufacturer's instructions and your quality system.