How Does a Craftsman Bolt-Out Set Work?

Bolt-outs resemble the sockets of a ratchet wrench set but grip the head of a bolt with left-handed cutting jaws instead of hexagonal socket sides.


Bolt-outs sometimes remove rusted bolts easily.
Bolt-outs grip the sides of bolt heads already damaged by other tools. Driven by ratchet wrenches or impact wrenches, the bolt-outs give users a second chance at removing stubborn bolts and lag screws. Hasty use of a bolt-out can cause more damage, so prep the bolt correctly before starting. .

Craftsman bolt-out sockets come in a range of sizes that fit either metric or English bolts and nuts. After selecting the correct size for the task, users tap the open end of the bolt-out securely over the damaged bolt or nut. Careful tapping with a mechanic's hammer drives the cutting jaws of the bolt-out securely into the sides of the bolt head. Keeping the bolt-out in line with the bolt shaft gives the best grip. Setting the bolt-out in place at an angle causes uneven torque during removal. Inserting the square drive bit of an impact wrench or ratchet wrench allows counterclockwise rotation of the bolt.


Using too much force when driving the bolt-out into place can shatter the bolt-out itself. Tap the bolt-out just hard enough to move the socket gradually deeper. Unless the bolt-out socket bites securely into the bolt or nut, the jaws can slip and round off the hardware. Once the bolt-out socket strips the bolt head, the bolt-out can't get a new grip, so check things twice before starting. For the best chance of success, repeat all possible steps that can loosen the problem hardware before risking the bolt-out method. Using heat, lubricants and other techniques first can prevent bigger problems.


Cleaning up the bolt and the hardware it fits gives the bolt-out a stronger surface to grip. A stiff wire brush removes surface rust and dirt that can interfere with removal. Once the visible parts are clean, soaking the threaded shaft with penetrating oil can reduce the force needed to extract the bolt by 50 percent, according to Popular Mechanics website. Give the oil 12 hours or more to soak in before trying to loosen the part. If the bolt cracks loose, stop and treat the parts with penetrating oil again before completely extracting the bolt. Don't rock the bolt clockwise, since that breaks the bolt-out's hold.


Stubborn, rusted bolts that don't yield to penetrating oil might loosen if heated. Torches can also ruin any combustible fittings near the problem part. Clean all oil off the parts before using a torch and clear the work space of any fire hazards. Heating one side of a rusted nut expands the metal unevenly and breaks the nut loose. Heating metal around a bolt expands the fitting instead. Metal threads break loose more easily while hot, but bolt-outs used on hot metal can also bend or shear bolt shafts. Heating can open gaps that admit penetrating oil, applied after the metal completely cools.

About the Author

James Young began writing in 1969 as a military journalist combat correspondent in Vietnam. Young's articles have been published in "Tai Chi Magazine," "Seattle Post-Intelligencer," Sonar 4 ezine, "Stars & Stripes" and "Fine Woodworking." He has worked as a foundryman, woodturner, electronics technician, herb farmer and woodcarver. Young graduated from North Seattle Community College with an associate degree in applied science and electronic technology.