So far mine has struck evertime I tried. It's not a replace all IMO, it requires considerable force to strike. Not that it's hard, the fat handle knob makes it easy to use since it fits the palm with more surface area. I remember my hand getting sore when I needed to use an auto center punch so much in a short period of time. The knob is fixed with the rest of the handle, the entire handle turns when adjusting. For more delicate work/thinner materials I'd use a smaller one.
Here's the auto center punches I have in the garage. Left is a cheapie from Enco (not sure why I still have it), Starrett 18A & 2 Generals.
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Same order, max tension on all, 16ga square tubing. The arrow is pointing to the Enco in case you can't see it. Not sure why I haven't tossed that thing out already. It's worthless, barely leaves a mark on steel maxed out & doesn't strike half the time. The Rennsteig is just slightly stronger than the larger General I have but it's a lot more comfortable to use
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The adjustment for force doesn't seem to be a great range of change. Again on thinner materials I'd prefer to use something smaller. This is aluminum just under 60 thou thick. Top set of punches is the Rennsteig, set from low to high, no particular order. Bottom 3 is the Starrett 18A, set mediumish
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Backside
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I like it & I hope to use it more often than my I did with my others but still I prefer a punch & a hammer at home. Unfortuantely the thing is too fat to fit in the drawer that I keep my auto center punches in. Need to find a place for it where I don't forget & easily accessible otherwise It may never get used.