Stuck Mic

I have a 1/2 inch mic (Browne and Sharp #6) with a ratchet. The spindle is stuck on the anvil and the thimble turns freely in either direction. I've removed the ratchet screw and its pieces from the rear. I'm soaking the mic in breakfree. I've tried turning the spindle with a soft jaw pliers but it won't turn free.

Any suggestions of how to get this mic back to working order.

Thank You

This method is not 100% perfect and there is usually some corrosion damage that needs fixing after.

First remove the thimble. The ratchet and screw are already off so just break free the taper that is holding the thimble to the stem. A sharp tap near the knurled area with a aluminum hammer or piece of aluminum stock will usually do it.

Once the thimble is off look at the backlash nut area checking for corrosion in the thread area. Remove the nut if needed to check. If there is lots of rust you might as well give up on the mics. If not soak this area in break free as well and replace the adjustment nut but leave a little loose.

Get yourself some strips of belt leather. I save old work belts for this purpose. (belts off trousers not machines). Put one strip in your bench vise and clamp the mic frame. Put the other on the jaws of a pair of small vise grips and clamp the stem just past where the stem and anvil touch. With luck you can now break it free without using heat.

I have only had one case where the anvil and stem had corroded together. Once free a hard stone will clean things up. Most of the stuck mics I worked on had galled or rusted threads. You can free them up a bit but they are not good for accurate measuring afterward.

Walter A.