This geometry produces virtually no stress concentration. Chisel away enough material from around the screw head to allow you to grip the screw with pliers or vise grips. Next, a metal ruler or straight strip of steel is laid against the other side of the drill and clamped to the drill press table. Maybe you start with the slot pointing North and it goes in 5 turns and fetches up pointing ENE. What is the thinnest slitting saw you can buy?
Extracting Phillips, Torx and Robertson Screws
If you can use a screwdriver or drill, you can conquer the keyhole-picture hanger. Hang your pictures with a keyhole opening securely the first time; no guesswork and no extra holes to fill. Obtain bear-claw anchor hangers, or double-headed screws with heads large enough to stay in the topmost slot of the keyhole.
If your picture weighs over 30 pounds, you will need a bear-claw screw with an anchor. Determine the approximate wall position for each picture. Trace around each picture in the grouping onto a large piece of butcher or brown wrapping paper and tape it to the wall if you are hanging several pictures at the same time.
This gives you an idea of the picture layout for the wall. Remove the paper before hanging your pictures. Measure from the top edge of the picture frame to the top edge of the keyhole opening. Measure from the side edge of the picture frame to the side edge at the top of the keyhole opening.
Place a small piece of painters' tape on the front of the picture at the junction of these measurements from the back. When complete, you will have marked the corresponding location of the keyhole opening onto the front of the picture.
Pull off a dime-sized piece of removable adhesive and insert it inside the top straight slot of the keyhole opening. Slide a thumb tack, head side against the adhesive, into the keyhole opening. The point of the thumb tack sticks out at the end of the long slot of the keyhole. Wiggle the thumbtack to make good contact with the top surface of the tack and the adhesive; ensure that the point protrudes at a degree angle from the surface of the frame.
Hold the picture on the wall at its chosen location. Gently push on the spot marked with the painters' tape on the front of the picture. Insert a self-drilling wall anchor into the point marked by the tack, using a screwdriver or drill with the appropriate bit to match the screw, such as a flat-head or Phillips. Insert a bear-claw hanger into the anchor with a screwdriver or drill.
Some likely candidates include:. You sometimes can work a small flat-head screwdriver into one of the crossed slots on a Phillips screw, and you may be able to work a corner of the blade into the slot of a torx or Robertson -- square-head -- screw. If you don't even have a flat-head screwdriver, you're not completely out of luck. Some likely candidates include: Choose one with a rounded tip, such as a butter knife.
Insert the tip of the blade into the screw slot and angle the handle down a bit to give yourself leverage. Remember "righty tighty, lefty loosey," which reminds you to turn the screw counterclockwise. A coin -- preferably a dime, which is thin enough to fit in most screw slots. If you can't turn the coin with your fingers, grip it with pliers. If the screw isn't screwed in very tightly, you may be able to turn it with any plastic card -- even your driver's license.
Put the rubber band over the screw and press down in it with your finger or a hard implement and apply a counterclockwise force. The traction of the rubber against the screw often is enough to make it turn.
A chisel , which does an even better job of turning single-slot screws than a flat-head screwdriver.