TM reader nrChris writes: “I bought this Harbor Freight dial indicator to check runout on my new — and in need of a rehab — table saw. It’s amazing: flip the switch and it’s a very strong magnet. Flip it again and it’s inert. The best part is that this features a standard thread — 5/16″ I think — so you can re-purpose them nicely. I’m going back for a few more to use with tablesaw jigs and featherboards while they’re on sale.”
Checking online, we discovered it offers a 12″ reach with a swivel post, swivel snug, gauge rod, and indicator clamp, plus knurled thumbscrews to lock everything in place. Sadly, the sale Chris found doesn’t appear online, but they normally run $18. You might have better luck checking in HF’s brick-and-mortar locations, though.