If the screw head is worn but intact, purchase a screw extractor. A typical extractor is essentially a screwdriver bit made of extra-hard metal, reverse threaded right at the tip. This is one of the most consistent ways to remove a stripped screw, but it does require caution. If the extractor breaks off in the screw, it may require a professional to finish the job. To reduce the chance of this happening, choose an extractor no more than 75% of the diameter of the screw shank (not the head). For Torx or socket cap screws with an exposed cylindrical body, use a multi-spline extractor. This fits over the head of the screw, and engages it with splines (teeth) on the inner surface. Instead of following the instructions below, tap this type of extractor gently into place, then turn with a socket wrench. Place a center punch on the exact center of the screw head. Strike the end with a hammer to create a dent for your drill. Wear eye protection to protect yourself from flying shards of metal. Keep them on throughout this process. Use a drill bit designed for hard metal. The screw extractor should have the drill bit size stamped somewhere on the tool. Drill slowly and stabilize it with a drill press if possible. Start with a hole ⅛ to ¼ inch (3–6 mm) deep; going too far may break the screw. It helps to start the hole with a small drill bit to give the larger one a place to grip. The extra-hard metal of the extractor is brittle, so an iron or steel hammer could break it. Tap it in until the extractor has a firm grip on the walls of the hole you drilled. If the torque is too forceful or uneven, the extractor may break, leaving you worse off than before. A tap handle that fits snugly over the head of your extractor is by far the safest way to remove the extractor and attached screw. The drilling should have loosened the screw, so you can often remove it without much force. Some extractor kits come with a nut that fits over the extractor head. Grip the nut with two wrenches about 180º from each other, for a more equal torque. If the screw doesn't budge or you're concerned the extractor might break, remove the extractor. Heat the screw with a torch, then drip paraffin wax or water on it to lubricate the threads. Try the extractor again once the screw has cooled. Take care not to damage the surrounding material. Even when working with metal, it's best to stick to heat guns or propane torches. Move the torch around the screw constantly to avoid heating any one spot for more than a second at a time.
एक स्क्रू एक्सट्रैक्टर लें: स्क्रू हेड के बीच में एक छेद पंच करें: स्क्रू हेड पर एक छेद ड्रिल कीजिये: एक्सट्रैक्टर को पीतल (ब्रास) की हथौड़ी से टैप करें: एक्सट्रैक्टर को सावधानी से घुमाएं: अगर स्क्रू न निकले तो उसे गर्म करें: