Ask THIS OLD HOUSE
Q) My Phillips-head screwdriver can’t get a good grip on many of my screws, even though it looks like it should fit. What’s the story? —VAL BARDAWIL, WORCESTER, MASS. A) You need a different screwdriver. Pozidriv screws, like the ones shown here, do look a lot like Phillips-head screws, but each recess has four extra notches, which prevent the bit (inset, right) from slipping out when torqued. Phillips bits (inset, left) are actually meant to back out when twisted hard and thereby save the screwhead from being snapped off.