Best way to stop vise jaw lift

I’m getting a slight curl on parts when clamping in a Kurt-style vise on the Bridgeport; a sweep with the dial shows the movable jaw lifting about 0.002" when I bear down. Beyond tapping down on parallels and a paper shim at the fixed jaw, what old-school fixes have worked for you — stone the bed, small spacer at the back, or change the clamping order?

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I’d pull the moving jaw, clean and lightly stone the ways and the jaw’s underside, then snug while pushing down on the jaw cap — tiny burrs there are usually the 0.002 culprit. Step jaws to “clamp low” help the seesaw effect; @OP are you on a swivel base?

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After cleaning like @hscott77 said, the biggest change for me was ditching the swivel base and bolting the Kurt straight to the table — on my Bridgeport it cut jaw rise from about 0.002" to nothing; if you have to keep the swivel, put a tiny top-toe on the soft jaws. Are you on a swivel base?

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Soft jaws with a shallow step so the part contacts “below centerline” will preload it down and wipe out that about 0.002" rise. If you don’t want to cut jaws, a narrow shim only at the top of the movable jaw (not the fixed) does the same trick. Are you clamping near the screw or way out at the toe?

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Quick trick: slip a short 1/8" dowel behind the moving jaw, up near the top, snug to preload the slide down, pull the pin, then finish torque — that “back pin” move usually erases about 0.002 like a tiny crowbar. If it works, make it permanent with a setscrew pin behind the jaw instead of fussing with shims; do you have clearance back there?

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On my Bridgeport, the quickest fix was a thin shim under the rear mounting ear of the Kurt — about 0.0015" — to cancel a about 0.002" rise; , that curl drove me nuts. It’s cheap and reversible, but it will shift if you relocate the vise or change how hard you crank, so I still ‘stone the bed’ lightly and keep the sliding side spotless like @hscott77 noted. What torque are you putting on the handle?

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